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green Roofs

A Resource Manual for Municipal Policy Makers

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Authors

Gail Lawlor Beth Anne Currie Hitesh Doshi Ireen Wieditz

May 2006

Canada Mortgage and Housing Corporation supports the Government ofCanada policy on access to information for people with disabilities. If youwish to obtain this publication in alternative formats, call 1 800 668-2642.

Canada Mortgage and Housing Corporation

Green Roofs:A Resource Manual for Municipal Policy Makers


Green Roofs : A Resource Manual for Munic ipa l Pol icy Makers

Advisory Committee

Region Name Contact Information

West (B.C.) Dale Mikklesen City of Vancouver (604) [email protected]

West (Alta.) Kerry Ross Studio T Design (403) [email protected]

West (Man.) Rodney McDonald McDonald and Hardess Sustainability Group Inc.(204) [email protected]

Central (Ont.) Karen Moyer City of Waterloo (519) [email protected]

Central (Ont.) Jane Welsh City of Toronto (416) [email protected]

Central (Que.) Owen Rose Urban Ecology Centre, Montreal (514) [email protected]

Véronique Jampierre Vivre en [email protected]

East (N.S.) Kendall Taylor Kendall Taylor Architect (902) 441–[email protected]



Executive summary

This Manual is an overview of international and Canadian green roofpolicies and programs. By reviewing the reasons municipalitiesthroughout the world have set green roof policies and program, policymakers can better determine which policies suit their needs.

European jurisdictions have long used green roof technology forstormwater management, to reduce energy use in buildings and toincrease amenity space. Green roofs are gaining acceptance throughoutNorth America as knowledge of the environmental benefits and as thetechnology for green roofs improves.

In Europe, intensively competitive market forces are drivingdevelopment of green roof technology. These forces include years ofaccumulated research on membrane technology, roof design and plantperformance. Social ideals in Europe that value environmentalprotection and increasing green space in urban areas also drivedevelopment of green roof technology.

Canada does not have the same social conditions and market forces asEurope, but Europe’s experience has lessons for Canadianmunicipalities considering green roof policies and programs. ThisManual gives examples of North American and world green roofpolicies and programs. From the examples, policy makers may find agood fit for their situations.

Green roof policies and programs are most often one feature of wide-ranging policies and programs that promote more green space in denseurban areas and propose alternatives to standard stormwaterinfrastructure.

Research program

This Manual features 12 jurisdictions that demonstrate leadership in

green roof policy development. These jurisdictions have successfullyestablished supportive programs and succeeded in significantlyadvancing the green roof movement in their communities.

Discussion of 13 additional jurisdictions with less developed greenroof policies also has useful insights and benchmarks to give a morecomplete picture of green roof development. Understanding thedriving influences behind the widespread application of green roofs isthe key to developing programs supporting the technology.

An advisory committee made up of representatives from acrossCanada guided the Manual’s research team. The committee wasessential in selecting the example jurisdictions and advised on thecontent of each case study.

The advisory committee and the research team picked the 12jurisdictions because of the maturity and type of their green roofpolicies or programs, key motivators and their success in promotinggreen roofs.

Green roof policy and programs in each municipality are unique tothe local climate, political position, environmental motivators andresource capacity. To capture the different approaches and diversenature of green roof programs, the following headings highlightactivities in the selected jurisdictions:

� Description of jurisdiction

� Key motivators

� Green roof policy

� Process to establish policy

� Effectiveness

� Lessons learned

� Future predictions

� Applicability to Canada (international jurisdictions only).

The key motivators are the need to:

� Control stormwater runoff

� Reduce urban heat-island effect

� Lower building energy consumption

� Reduce air pollution

� Increase green amenity space

� Maintain biodiversity

� Reduce escalating infrastructure costs.

The Manual features the following municipalities:

Canada United States International

Montréal Chicago, Ill. Basel-City, Switzerland

Toronto New York city Münster, Germany

Vancouver Portland, Ore. Singapore

Waterloo Stuttgart, Germany

Tokyo, Japan



The Manual outlines six phases in setting appropriate green roofpolicies and programs:

� Introductory and awareness

� Community engagement

� Action plan development and implementation

� Technical research

� Program and policy development

� Continuous improvement

Municipalities can use many tools and incentives to encourageimplementation of green roofs and stimulate the local market. They include:

� Education and champions

� Indirect financial incentives

� Direct financial incentives

� Regulatory measures

� Performance rating systems

Building codes and regulations



Table of Contents

Advisory Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Executive summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Part 1 — Introduction to green roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

What is a green roof? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Key motivators for green roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Green roof policy development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Tools to encourage green roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

FLL guidelines for green roof design, construction and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Background — the green roof movement in Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Part 2 — Green Roof policies worldwide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Montréal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Toronto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Vancouver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Waterloo, Ont. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

United States of America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Chicago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

New York . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

Portland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

International . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Basel-City, Switzerland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Münster, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Singapore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Stuttgart, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

Tokyo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

Part 3 — More case studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

Calgary, Alta. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

Halifax, N.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Ottawa, Ont. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Québec City, Que. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89

Winnipeg, Man. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93



United States of America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96

Atlanta, Ga. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97

Minneapolis-St. Paul, Minn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100

Pittsburgh, Penn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103

Seattle, Wash. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106

Washington D.C and Chesapeake Bay Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109

International . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112

Berlin, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113

London, U. K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

North-Rhine Westphalia, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120

Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122



Part 1 — Introduction to green roofs

This section of the Manual is a general description of green rooftechnology, key motivators, policy phases, incentive tools and buildingcodes.

What is a green roof?

In this Manual, a green roof is a conventional flat or sloped roofamended with some or all of the following layers or elements:

� structural support

� vapour control

� thermal insulation

� a waterproofing membrane

� a roof drainage layer

� a root-protection layer

� synthetic planting media

� hardy, drought-resistant plants.

As Figure 1 shows, designer or building owners may adjust or enhancegreen roof layers based on their vision and guiding principles.

Figure 1 — Green roof layers1

Green roof terminology

“Extensive” and “intensive” are the two main terms describing greenroof design. These terms describe differences in construction, designand costs. Extensive green roofs, which have a thin growing medium,are the most typical.

Extensive green roofs use a substrate depth ranging between 5 and 15 cm (1.97 and 5.91 in.) and weigh between 72.6 and 169.4 kg/m2

(160.06 and 373.46 lb./sq. ft.). This shallow planting media (low-weight, soil-less) helps minimize costs and the total structural load.These low-weight synthetic planting media, combined with thechallenging winds, drought and high-temperature microclimates on anelevated surface, make hardy, low-height, drought-resistant plantspecies necessary.

Comparatively less maintenance is needed to install and maintain anextensive green roof; however, the success of any roof is measured bythe survival of the plants. Ongoing plant and substrate research iscontributing to green roof success across North America.

Intensive green roofs can be designed for unique and esthetic amenityor recreational space, including public access. Intensive green roofsfeature deeper planting media, irrigation systems, complex landscapingfeatures and a broad range of plant species. They can support largeplant species such as trees, shrubs, ponds, waterfalls and otherdecorative features. Engineered roof surfaces that can accept heavierweights support the deeper growing media of intensive green roofs.Intensive green roof retrofits may require roof structure upgrades.They may also cost more for materials, labour, design features andheavy equipment, such as overhead cranes to get materials to the roof.

Key motivators for green roofs

Key motivators are factors that lead communities to consider greenroofs as an effective way to reduce pollution and to reduce the effectsof dense urbanization.

Key motivators include:

� stormwater runoff affecting drinking water and habitat in localrivers and lakes

� increased impervious surface areas and urban heat island effect

� energy demand in commercial and residential buildings;

� deteriorating air quality

� lack of green space for social and recreational use

� increasing loss of biodiversity.

7

1 Moran,A., Hunt, B. & Jennings, G. (2003). A North Carolina Field Study to Evaluate Green Roof Runoff Quantity, Runoff Quality and Plant Growth. St. Joseph,Michigan:ASAE (American Society of Agricultural Engineers) and Currie, B.A. (2005) Air Pollution Mitigation with Green Roofs Using the UFORE Model.Unpublished MASc. thesis, Ryerson University,Toronto

8 Canada Mortgage and Housing Corporation


Stormwater management

Impervious surfaces—concrete sidewalks, paved parking lots, streetsand highways, building walls and conventional roofs—dominateurban landscapes. These impervious surfaces direct stormwater intostorm gutters, sewers and engineered channels.

Some older urban areas still have aging combined storm and sewageinfrastructure. In these areas, the sewers reach maximum capacitymore quickly and discharge runoff water mixed with untreated sewagedirectly into receiving lakes and rivers. Runoff reaches these receivingwaters in uncontrolled surges that destroy natural habitats and depositcontaminants, such as suspended solids, heavy metals, chlorides, oilsand grease, into local waterways.

Stormwater management is a concern for municipalities everywhereand they are looking at green roofs as an alternative to costlyinfrastructure. Vancouver, Toronto, Waterloo, Portland and severalcities in Germany are examples of municipalities concerned aboutstormwater management.

Urban heat island effect

The most frequently documented climatic effect of urbanization is thedifference in surface and air temperatures between urban andsurrounding rural areas.

Dense urban areas can cause temperature increases as high as 10°C(50°F). This heat results from modifications to surface areas, such asincreased use of asphalt and concrete, coupled with the atmosphericchanges caused by motor vehicles.

The hard, heat-absorbent surfaces of cities retain more heat than areaswith more vegetation and plant life. This “heat island” phenomenon isthe result of ground-level air temperature being much higher than insurrounding rural areas, where the vegetation and plant life cool theair through moisture retention and subsequent evaporation andtranspiration through their leaves. New York and Chicago are bothparticularly concerned with urban heat island effect.

Figure 2 — Rural and urban area heat characteristicsSource: http://www.epa.gov/heatisland/about/index.html

Energy demand

Recent green roof research 2 in Canada supports European findingsthat green roofs (coupled with insulation) reduce overall buildingenergy demand. The insulating effect of a green roof also reduces thepenetration of ultraviolet energy in summer. Together, these effectsprolong the life of the roofing membrane. Green roofs, though, maybe less effective at preventing the escape of heat in the winter.

Nonetheless, the greater energy savings in the summer are significant.The savings are the result of the cooling effects of evapo-transpirationwithin the plants and the evaporation of retained moisture from thesoil. Since climatic conditions and architectural standards vary acrossCanada, research results must be interpreted in terms of where thestudy was undertaken and how relevant they are to that particular area.

Air pollution

Air pollution is a trans-boundary issue. Pollution is worse in hotsummer conditions and exacerbates pre-existing health concerns for

both young and the elderly. Local solutions to air quality concernsinclude anti-idling bylaws, smog summits, improved urban transitsystems, bio-diesel for city vehicle fleets, hybrid vehicles and phasingout coal-fired electricity plants.

Among the solutions is restoration of biological systems that helpreduce airborne contaminants, such as more urban trees, shrubs andgreen roofs. Singapore and Toronto, two of this Manual’s examplemunicipalities, have primary research quantifying the effect of greenroofs on air pollution.

2 Bass, B., Stull, A., Krayenhoff, S., & Martilli, R.B. (2002). Modeling the Impact of Green Roof Infra-structure on the Urban Heat Island in Toronto.The GreenRoof Infrastructure Monitor. 4 (1).Bass, B., Krayenhoff, S., Martilli, A., Stull, R.B. & Auld, H. (2003, May).The Impact of Green Roofs on Toronto's Urban Heat Island. Presented at the GreeningRoofs for Sustainable Communities Conference, Chicago, Ill.Liu, K. & Baskaran, B. (2003, May).Thermal Performance of Green Roofs through Field Evaluation. Presented at the Greening Rooftops for SustainableCommunities Conference, Chicago, Ill.Liu, K. & Minor, J. (2005, May). Performance Evaluation of an Extensive Green Roof. Presented at the Greening Rooftops for Sustainable CommunitiesConference,Washington, D.C.



Amenity space

Many urban buildings stand on busy streets and transportation routesand have little access to green space. Green roofs provide a measurablepsychological benefit to urban dwellers by adding tangible, accessible,natural space for social interaction, recreation and relaxation.

A green roof offers building occupants proximity to green commonspaces. Residential condominium developers are starting to realizepositive economic benefits from green roofs as the rate of occupancy,the index of satisfaction and the overall positive experience from greenroofs become brisk sales and longer tenancies. Green roofs have beenshown to provide positive amenity space in Singapore, Vancouver,Toronto and Ottawa.

Biodiversity

The expansion of urban spaces and built form has led to habitat lossand fragmentation for many animal species. Green roofs can providesuitable habitat and refuge space for many bird and invertebratespecies in urban areas. Green rooftops can be designed to play two keyroles: they can be a “stepping stone habitat,” connecting naturalisolated habitat pockets with each other, or an “island habitat” that isseparate from habitats at grade for less mobile species. Becauseroofscapes make up 15 to 35 per cent of the urban footprint, theyhave great potential to mitigate lost biodiversity. Basel, Switzerlandand London, England have successfully used green roofs for beneficialhabitat for bird and invertebrate species.

Phases become successively more time- and resource-intensive. Phase 6involves improving current programs, usually because new challengesarise or current programs are not successful. This typically involvesrevisiting Phase 4 to conduct further research or revisiting Phase 5 todevelop new programs better suited to current challenges.

9

Figure 3 — The six phases in developing green roof policies and programs



Green roof policy development

There are six phases in establishing a green roof policy. This Manualdiscusses jurisdictions that represent each phase in more detail in latersections. The policy phases this Manual describes are not rigidclassifications. Jurisdictions may be at different phases at the sametime and they may return to an earlier phase if they need to.

Phase 1: Introductory and awareness

In this phase, a jurisdiction looks at the merits and environmentalbenefits of green roofs. The municipality may hold a green roofworkshop, send delegates to a green roof conference or visit ajurisdiction with existing green roofs or a green roof policy.

Green Roofs for Healthy Cities (greenroofs.org3) has been key in helpingNorth American municipalities organize green roof workshops to bringlocal stakeholders together. In this phase, a local champion is usuallydeclared who may act as a spokesperson for the jurisdiction. Winnipeg andOttawa are examples of municipalities in this phase. (www.Greenroofs.com4

has a comprehensive overview of green roof technology).

Phase 2: Community engagement

A local champion or a green roof committee may seek any number ofcreative methods to raise the profile of green roofs. There may be meetingswith community leaders, mayors, architects, landscaping professionals,building owners and environmental groups to gain support for greenroofs. Funding sources, such as government programs, utilities orgreen roof manufacturers, will be explored and negotiated.

The champion or committee will outline the opportunities, threats,strengths and weaknesses of green roof development in the municipality.An extremely harsh climate is a potential threat; a large number of flatroofs are an opportunity. Halifax and Calgary are in phase 2 and arenearing phase 3, with plans for green roof demonstration sites and research.

Phase 3:Action plan development and implementation

The municipality or the community may establish a green roof advisoryor working committee made up of key community leaders. A greenroof demonstration project may be launched with or without scientificmonitoring equipment, depending on the need for local research data.Green roof tours and ongoing planning meetings often include sitevisits to buildings with different types and designs of green roofs, leadingto the establishment of a green roof database or inventory. A review ofexisting policy options and tools may be explored in this phase andvarious programs and policy opportunities identified. Minneapolis-St.Paul, in Minnesota, is an example of a municipality in this phase.

Phase 4:Technical research

The local green roof advisory committee or the local champion(s), orboth, along with a possible consortium of public-private partnershipsset up a research site. In some cases, the technical research is demonstrationprojects or green roof installations on prominent site, such as the greenroofs on the Toronto and Chicago city halls. A jurisdiction exploringgreen roofs as a step in setting green roof policy needs local researchdata with outcomes that can be applied to any or all of the key motivatorsprioritized in the jurisdiction. The National Research Council of Canada(NRC) has provided technical assistance to many research projects.

In the technical phase, researchers investigate and quantify the benefitsof green roofs, which will become part of green roof policy and designguidelines. Research typically involves assessing the ability of green roofsto manage stormwater, mitigate the urban heat island, or provide othernecessary environmental benefits. Typically, jurisdictions with monitoreddemonstration sites collect and prepare findings for conference proceedings,which are shared at international green roof conferences. Sharing dataand research findings is an important part of the technical research phase.Toronto, Waterloo, Vancouver, Montréal and New York are examplesof municipalities in this phase.

Phase 5: Program and policy development

The green roof advisory committee may expand to include more professionals,such as landscape designers, horticulturalists, designers and municipalurban planners. This phase translates local and regional research into policyoptions and tools. This involves establishing ways of offering incentivesto contractors, developers and building owners to retrofit or plan newbuildings with green roofs. This can include financial incentives, tax creditsor density bonuses. Chicago, Portland and Singapore are in this phase.

Phase 6: Continuous improvement

At this phase, a jurisdiction has achieved maturity and familiarity withgreen roof technology. Now, the jurisdiction assesses the effectiveness ofpolicies and programs and decides whether to continue on the samepath or explore other policy options.

To gather information and assess program success, there must be a mechanismto collect and analyze constructive feedback from users, professionalsand the building community. Phase 6 typically involves exploring otherpolicy options or further research to fine-tune existing programs.

One German jurisdiction had to include policy language requiringmaintenance of green roofs for a specified period, as some owners neglectedtheir green roofs and the roofs did not achieve their expected environmentalgoals. The German cities of Stuttgart, Münster and Berlin and thestate of North Rhine Westphalia are in this phase.

3 Retrieved November, 2005. English only.4 Retrieved November, 2005. English only.



11

Jurisdiction Phase 1Introductory

Phase 2Communityengagement

Phase 3 Action plan and implementation

Phase 4 Technicalresearch

Phase 5 Program and-policy development

Phase 6 Continuousimprovement

Montréal Done Started in thelast year

Demonstrationroofs

Ongoing forseveral years atuniversity level.Field monitoringstarting soon

Very initial stages Not there yet

Toronto Done Started in 2001 Demonstrationand researchprojects (univer-sity and commu-nity) and a prolif-eration of greenroofs across city

Technical datasupportingconference papers/proceedings since2003;partnershipswith EnvironmentCanada/NRCongoing;Cost-benefitanalysis 2005

Predicted for 2005 Not there yet

Vancouver Done Started in 2001 Stormwatermanagementplanning forGVRD includesgreen roofs

B.C. Institute ofTechnologylaunched the firstCanadian greenroof researchcentre in 2004

Each munici-palityconsidering program/policyoptions for 2006

Not there yet

Waterloo Done Well underwayfor a few years

Green Roof Feasi-bility Studycomplete

Demonstrationproject withresearchcomponent hasbegun

Initial stages Not there yet

Chicago Done Started in 2001 DemonstrationProject on Chicago City Halland the Centrefor Technology

Proliferation of greenroofs across the city;technical datasupportingconferenceproceedings;major is local champion;proliferation of greenroof technology inthe State

Programs sup-portstormwater mitigation,public education andmunicipal incentivesoffered at the buildingpermit level

Not there yet

New York Done Well underwayfor few years

Demonstrationroofs

Significant primaryresearch completedincluding cost-benefit analysis

Very initial stages Not there yet

Portland. Well past Well past Many plans implemented

Significant technicalresearch related tostormwater benefitsdone

Well underway Started



Table 1— Policy phases of selected jurisdictions

Jurisdiction Phase 1Introductory

Phase 2Communityengagement

Phase 3 Action plan and implementation

Phase 4 Technicalresearch

Phase 5Program and-policy development

Phase 6 Continuousimprovement

Basel Well past Well past Well past Significant amountof research onbiodiversity

Incentive program in1996–97.Another programplanned for2005–06.Required for all flatroofs

Looking intoquality controlmeasures

Münster Well past Well past Well past No evidence Had various incentive programs(now defunct).Stormwater fee.State-level incentive program

Not mentioned

Singapore Well past No evidencefound

Well into it Significanttechnical researchrelated to life cyclecosting and energybenefits done

In place Underway

Stuttgart Well past Well past Well past No evidence Financial incentiveprogramRegulated in localdevelopment plans

Looking intoquality controland inspectionmeasures

Tokyo No evidence Not much evi-dence

Well into it Some researchcompleted and noevidence anythingongoing

In place and beingextended to beyondTokyo and at countrylevel

Started



Tools to encourage green roofs

There are a number of incentives and tools to encourageimplementation of green roofs. These vary in financial, time andadministrative commitment.

Indirect financial incentives

Indirect incentives recognize green roofs as one environmental toolamong many. The tools range from improving the energy efficiency ofa building to Münster’s tax for stormwater disposal. In Munster,installing a green roof along with other stormwater source controlsreduces the amount of tax paid, which gives building owners anindirect financial incentive to install a green roof. The Ontariomunicipality of Waterloo is considering a reduced stormwater utilityfee for buildings with green roofs.

Direct financial incentives

Direct financial incentive programs cover some building costs forgreen roofs. There are usually specific conditions, verified in anapplication process, to qualify for the funding. The conditions caninclude minimum water-retention capacity, growing-mediumthickness and a contract binding the building owner to regularmaintenance of the green roof.

Cities in Germany, Belgium and the province of Quebec have directfinancial incentive programs running from three to 20 years.

Other financial incentives, such as tax credits, fee waivers and densitybonuses, do not require substantial financial investment.

For example, a municipality can waive all or part of the developmentcharges for buildings designed with green roofs. Municipalities canalso waive fees for official plan and zoning bylaw amendments,consents, development agreements, minor variances and buildingpermits for buildings designed with green roofs.

Density bonuses are another tool. The municipality allows floor spaceor building height beyond zoning bylaw regulations if there areresulting community benefits.

In Portland the “ecoroof” (or green roof ), floor area ratio (FAR)bonus is expected to provide additional development potential. Thisadditional potential can be anywhere from one square foot to threesquare feet of additional development for one square foot of greenroof. Portland now applies the bonus to targeted areas, mainly in thecity’s central district.

Regulatory measures

Compulsory green roof installation can ensure that a specificgeographic area or urban space roofscape is greened. Regulatorymeasures can achieve specific and sustainable urban goals such asimprovements in air quality, urban heat island effect, stormwatermanagement and amenity space.

Regulatory measures can also set minimum properties for the greenroof, such as growing medium thickness or types of plants used. Thisapproach has been widely used in Germany. The following is aregulation from a German municipality:

All buildings with flat and sloping roofs up to an incline of 15 degrees are to be permanently greened with ground-coveringplants. Areas of vegetative decline greater than and equal to five m2

are to be replanted. Roofs with a total area less than 10 m2 areexempt from this rule, however, must be kept in good state.Growing medium depths must be at least eight to 10 cm in depthand plants, seeds, or sprouts must be indigenous to the area. 5

Municipalities can also mandate compulsory roof greening for publicbuildings. Stuttgart sets aside funds every year to green the roofs ofpublic buildings. These roofs are usually greened when they areretrofitted.

Tokyo requires at least 20 per cent of a roof to be greened in newdevelopments or extensions to existing developments larger than1,000 m2 (10,764 sq, ft.) for private developments and 250 m2

(2,691 sq. ft.) for public developments. Failure results in a penalty ofapproximately 200,000 yen ($2,000 US).

Other tools and incentives

Green Roofs for Healthy Cities (GRHC), led by Steven Peck, is amajor force in green roof education, research and policy in NorthAmerica. GRHC initiated Green Roof workshops that have beencatalysts in awakening professionals and municipalities to the manybenefits of green roofs. This organization also launched the NorthAmerican Green Roof Conferences, which have been a focus of theNorth American green roof industry for several years. Theseconferences publicize research on technology advances,implementation case studies and policy. Most recently, GRHCinitiated green roof training workshops and has linked with the 2005World Green Roof Congress in Europe.

13

5 Ackermann,A. (1995), “Dachbegrünung aus der Sicht des Stadtplaners,” Das Gartenamt, 44(2), 73–80, and Dürr, A. (1993), “Dachbegrünung imBauplanungsrecht,” Landschaft Architektur, 23(3), 48–51.



LEED™

Throughout North America, Leadership in Energy and EnvironmentalDesign (LEED™) is raising the profile of green roofs and othersustainable or green building practices that are more typical in Europe.

LEED is a U.S.A.-based, non-governmental, rating system, which theU. S. Green Building Council (USGBC) administers. It is a voluntarysystem for rating new and existing commercial and institutional buildings.Developers and building designers who want accreditation for a projectuse LEED. Portland, Atlanta and Chicago promote LEED certificationfor all new and retrofitted buildings that meet specific dimensions,particularly for city-owned projects.

LEED evaluates environmental performance based on a “wholebuilding design” perspective over a building’s life cycle. This provides a standard to measure against the proposed components of a newbuilding. For more information about life-cycle analysis, see theAthena website at www.athenasmi.ca/index.html.6 LEED criteria guideconsideration of several environmental design features, including waterand energy conservation, innovative design, indoor air qualityimprovements, reduced urban heat island impacts, reduced impacts onwildlife and several other criteria that green roofs may support to agreater or lesser degree.

LEED provides ratings in credits or points: LEED Certified (26–32points), LEED Silver (33–38 points), LEED Gold (39–51 points) andLEED Platinum (52–69 points).

LEED™ Canada — Canada Green Building Council

The Canada Green Building Council (CaGBC) promotes the designand construction of green buildings. The Council is a coalition ofrepresentatives from different segments of the design and buildingindustry. The Council works to change industry standards and

develop best design practices and guidelines. Seehttp://www.cagbc.org/7 for more information.

LEED Canada for New Construction and Major Renovations version1.0 is an adaptation of the USGBC LEED Green Building RatingSystem, tailored specifically for Canadian climates, constructionpractices and regulations. The LEED Canada 1.0 Rating Systemrecognizes buildings that incorporate design, construction andoperational practices that combine healthy, high-quality and high-performance advantages with reduced environmental impacts. It ispromoted by the CaGBC.

LEED Canada’s rating system is voluntary, consensus-based, market-responsive criteria that evaluate a project’s performance from a whole-building, whole-life perspective and provides a common

understanding for what constitutes a “green building” in the Canadiancontext.

Some of the benefits of adopting LEED for Canada include:

� defines “green” within a common North American framework

� prevents “green-washing” as LEED is based on an externalcertification process

� relatively simple to implement

� flexibility, based on individual building specifications

� can be modified for local climate and building standards

� has legitimacy and consistency around the world

� provides credit for the installation of green roofs.

LEED Canada organizes its prerequisites and credits into the fiveprincipal LEED categories:

1. Sustainable Sites

2. Water Efficiency

3. Energy and Atmosphere

4. Materials and Resources

5. Indoor Environmental Quality.

“Innovation and Design Process” is an additional category for Canada.This category addresses sustainable building expertise and designmeasures not covered under the five principal categories

A unique aspect of LEED Canada is the credit for Durable Building(Envelope), which is credit MR 8 (Materials and Resources credit 8).It is based on CSA credit (CSA S478-96 (R2001) – Guideline onDurability in Buildings. This credit is relevant for Canada. While thiscredit does not deal directly with green roofs, it applies to green roofsas they are purported to considerably extend the lifespan of roofmembranes. Currently, there is one LEED product approved forCanada—LEED NC 1.0 (NC=New Construction).

See http://www.cagbc.org/8 for more information about LEED Canada.

Earning LEED™ Canada credits with green roofs

Green roofs are a recognized technology that can help designers anddevelopers achieve LEED credits. Green roofs may contribute up to11 LEED building credits by providing stormwater retention, energysavings through shading, heat island reduction by evaporative cooling,acoustical insulation, improved air quality and airflow, waterconservation, wildlife habitat and other environmental benefits.

5 Retrieved November, 2005. English only.6 Retrieved November, 2005. English only.7 Retrieved November, 2005. English only.



The following are some ways to earn LEED credits:

� Two LEED credits under the roofing credit by installing greenroofs to reduce urban heat island effect.

� One LEED credit under the non-roof credit for a green roof on thetop deck of a parking structure for reducing urban heat islandeffect.

� Two LEED credits for stormwater management as green roofsreduce runoff rates, peak flow and suspended solids.

� One LEED credit for green roofs, as they mitigate site disturbance

� One LEED credit for redeveloping a green space.

� Two LEED credits if the plants used on the green roof are drought-tolerant and require no irrigation, which improves the buildingwater efficiency.

Additional LEED credits can be sought by demonstrating that a greenroof (of a specified planting medium thickness and canopy coverage)may reduce the HVAC (Heat Ventilation Air Conditioning) loadrequired by a building, particularly in summer peak-demand. LEEDcredits may also be earned by optimizing energy performance.

British Columbia shows the most leadership in using LEEDcertification. In Winnipeg, the new Mountain Equipment Co-opbuilding, which includes a green roof, has earned LEED Goldcertification.

Green Globes

Green Globes is an online environmental auditing tool for designers,property owners and managers to assess and rate their existing buildingsagainst best practices and standards in areas such as energy use, wateruse, pollution management, hazardous waste, waste management andthe health of the indoor environment.

Similarly, Green Globes integrates principles of green architecture atevery stage of a project delivery for retrofits and the design of newbuildings. The Green Globes program produces a detailed online reportbased on a confidential questionnaire that can be filled out by buildingmanagers. Green Globes may also certify third-party verified projects.

There are several versions of Green Globes for different types ofprojects including; Green Globes U.S.A., GEM (GlobalEnvironmental Method) U.K. and Green Globes Canada, whichincludes a section for existing office buildings, existing light industrialbuildings and MURB’s (multi-unit residential buildings), design, fit-up and building emergency management.

Green Globes is the newest addition to the Building ResearchEstablishment Environmental Assessment Method (BREEAM)/GreenLeaf suite of environmental assessment tools for buildings. GreenGlobes audit criteria are based on the internationally acceptedBREEAM assessment method. The Canadian Standards Association(CSA) publishes BREEAM Canada as Plus 1132/BREEAM Canada.

The core premise of Green Globes is that environmental leadershipand responsibility make business sense. The following Canadianorganizations use BREEAM/Green Leaf tools:

� Public Works and Government Services Canada (PWGSC) for allfederally owned buildings.

� The Department of National Defence for the design of newbuildings

� The Federation of Canadian Municipalities for its MunicipalBuilding Retrofit Program

� The Hotel Association of Canada

� The City of Toronto Better Building Partnership

� Major property management firms

For more information about Green Globes go towww2.energyefficiency.org9

Local improvement charges

The Pembina Institute, an independent, not-for-profit environmentalpolicy research and education organization, promoted localimprovement charges (LICs) as a way to encourage energy efficientbuilding design and a tool that can be applied to green roofimplementation.10

This approach associates the additional cost of a measure with thebuilding property, rather than with the current building owner. Inother words, all owners, not just the current owner, share theadditional costs.

LICs are now used to help cover of infrastructure improvement costson public property, such as roads and sidewalks, which benefit a specificneighbourhood. The municipality pays for the improvements (usuallyfrom its annual capital budget). The municipality assesses the LIC onthe property taxes of the benefiting property owners until their shareof the improvements is paid. There must be an approval process,which includes obtaining agreement from a certain percentage of theproperty owners who benefit, before the municipality can levy LICs.

15

9 Retrieved November, 2005. English only.10 Pembina Institute. (2004). Using Local Improvement Charges to Finance Building Energy Efficiency Im-provements: A Concept Report. Drayton Valley,Alberta: Climate Change Control and BC Hydro.



For new construction, the additional cost of a green roof is includedin the LIC. This, for instance, would remove the capital cost ofbuilding a green roof from the sale price of a new home. The LICallows a homeowner to pay the additional cost in annual installments.

A major benefit of LICs is that by allowing the additional cost of thebuilding to be shared by all owners over time they deal with barrierssuch as long payback periods and higher up-front costs,. According toPembina, the Regional Municipality of Waterloo and Oshawa inOntario have LIC bylaws.

Ottawa is exploring LICs for capital projects, including green roofs.

The Pembina Institute web address is www.pembina.org11

FLL guidelines for green roofdesign, construction andmaintenance

A key player in the development of the green roof movement in Germanyis the FLL (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbaue.V. [The Research Society for Landscape Development and Construction]).Eight professional organizations established the FLL in 1975 toresearch plants and using them for environmental improvement. TheFLL is a not-for-profit, membership-based organization with about20,000 members that coordinates research, holds seminars andsymposiums and produces publications about landscaping and plants.

The FLL is widely known for its technical guidelines on green roofdesign, construction and maintenance. The guidelines set standardsfor the individual components of the system, construction techniquesand outline the maintenance for different types of roofs.

The FLL guidelines have been highly successful in setting quality standardsfor green roof systems throughout Germany. When the green roofconstruction boom first took off, many unqualified green roof companiessurfaced, leaving behind a legacy of poorly constructed green roofs.

The guidelines, now used by various sectors of the green roof industry,achieve several goals, such as:

� green roof manufacturers will design their products according tothe FLL guidelines thereby producing a more marketable product;

� jurisdictions that provide financial incentives require that allapplicants follow the FLL guidelines

� home and building owners are guaranteed a sound product whenpurchasing green roof systems and products designed according tothe guidelines.

FLL performance rating system

A key part of green roof policy is ensuring that a green roof achievesits performance goals or performs its ecological function. To do this,the FLL developed a performance rating system for green roofs to aidwith regulatory measures to ensure compliance.

The points-based system assesses the components and functions of thegreen roof. To obtain the base value, it takes the depth of the greenroof system that can be penetrated by the plant roots and assigns 10points for each centimetre of penetration. For example, if the depth is10 cm, the system’s base value is 100 points. From here, the systemsets performance criteria for four further categories:

6. water retention capacity of the drainage layer

7. water retention capacity of the growing medium

8. the number of plant species on an extensive green roof

9. the amount of green volume (m2/m3) for intensive green roofs.

Each category must meet certain criteria (for example, water retentioncapacity must be at least 25 per cent). If the criteria are not met,

points are subtracted from the base value and will have to becompensated for, either in the area where the deficit occurs, or in oneof the other categories.

Municipalities can use this tool to ensure that a green roof meets thedesired ecological functions. For instance, a municipality can designatea certain point value it wants to achieve for new development projectsand use the point system to ascertain what type of green roof (waterretention capacity, number of plants and so on.) will achieve thedesired value.12

11 Retrieved November, 2005. English only12 Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. (FLL). (1998). Bewertung von Dachbegrünungen: Empfehlungen zur Bewertung in der

Bauleitplanung, bei der Baugenehmigung und bei der Bauabnahme. Bonn, Germany.



Sample calculation using FLL point system

The following illustrates application of the point system. The projectis a shopping centre, Markt Brandenburg, in Berlin.

The following diagrams depict the extent of roof greening in the localdevelopment plan (Figure 4) and the extent of roof greening thedeveloper intended (Figure 5). A few adjustments to the design of thebuilding, such as extra storage space on top of the fifth floor and extraglass light covers on the roof of the first floor, reduced the roof areaavailable for greening. The point system is applied to determine howto compensate for the reduced area.

17

Adapted from: FLL 1998Figure 4— Extent of roof greening instituted in localdevelopment plan

Adapted from: FLL 1998Figure 5—Extent of roof greening the developer intended

Extensive green roof Intensive green roof

Area of building’s roof 2,420 m2 Area of the first floor roof 800 m2

Area after reduction of non-greenable areas, due to light

covers, vents, etc. (10%)

2,178 m2 Area after reduction of non-greenable areas, due to light

covers (10%)

720 m2

1. Combined depth of drainage layer and grow-ing medium

10 cm=100 pts/m2=217,800 points

2. Maximum water-retention capacity of growing medium

=at least 48%

3. Maximum water-retention capacity of drainage layer

=at least 15%

4. Number of plant species

=10

1. Combined depth of drainage layer and growing medium

20 cm=200 pts/m2=144,000 points


=at least 53%


=no value

4. Green volume

=0.50 m2/m3

Total (217,800+144,000) =361,800 points

Adapted from: FLL 1998

Table 2— Roof greening design requirements in local development plan



Table 3— Roof area available for greening on modified building

Table 3 shows the amount of space available for greening on the modified building and its associated point value.

A comparison of the extent of roof greening instituted in the local development plan (361,800 points) and the reduced roof greening because of the modified building design (329,800 points) shows a deficit of 32,000 points (assuming that all other factors remain constant), obliging the building owner to provide compensation.

There can be compensation for the quantitative deficit by increasing the growing medium thickness on the intensive green roof from 20 to 30 cm (8 to 12 in.) on the outer section of the first floor roof, an area of 558 m2 (6,006 sq. ft.). Table 4 shows the calculations.



Area after reduction of non-greenable areas, due to lightcovers, vents, etc. (20%)

1,938 m2 Area after reduction of non-greenable areas, due to lightcovers (15%)

680 m2

1. Combined depth of drainage layer and growing medium 10 cm

=100 pts/m2=193,800 points


=at least 48%

3. Maximum water retention capacity of drainage layer

=at least 15%

4. Number of plant species

=10

1. Combined depth of drainage layer and growing medium 20 cm

=200 pts/m2=136,000 points


=at least 53%


=no value

4. Green volume

=0.50 m2/m3

Total (193, 800+136,000 )=329,800 points




19

Table 4—Compensating for a point deficit

Increasing the growing-medium depth of the outer area of the green roof fulfills the re-quirements of the local development plan. The increasedgrowing-medium thickness also allows planting of larger shrubs and trees, which have greater ecological benefits and thus compensate forpossible qualitative losses from the changes. In this case, the point system ensures that the building owner complies with the development plangreening regulations and that the green roof can adequately mitigate the environmental damage13.

The advantage of this rating system is that it ensures ecological function and compliance with regulations, while allowing for flexibility in thedesign. It also allows policy makers to clearly define the type of green roof desired in policy documents, thus preventing14



Area after reduction of non-greenable areas, due to lightcovers, vents, etc. (20%)

1,938 m2 Area after reduction of non-greenable areas, due to lightcovers (15%) Outer (558 m2) +Centre (122 m2)=

680 m2


10 cm=100 pts/m2=193,800 points


=at least 48%


=at least 15%

4. No. of plant species

=10


Outer (30 cm)=300 pts/m2+Centre (20 cm)

=200 pts/m2=191,800 points


=at least 53%


=no value

4. Green volume

=0.50 m2/m3

Total (193, 800+191, 800 )=385,600 points


13 Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. (FLL). (1998). “Bewertung von Dachbegrünungen: Empfehlungen zur Bewertung” in derBauleitplanung, bei der Baugenehmigung und bei der Bauabnahme. Bonn, Germany.14 Krupka, B. (1994). “Ein Bewertungssystem für Dachbegrünung nach Punkten,” Das Gartenamt, 43(7), 448–450.



Figure 6— NRC Institute for Research in Construction, fieldresearch green roof facility, Ottawa summer and winter, 2003

Building codes and green roofs in North America

Consumers throughout North America look for general contractors whonot only follow local building codes, but also demonstrate eco-efficiencyand environmental sustainability in building practices. For example,consumers are demanding competitively priced roofing systems that satisfythe human need for comfort and energy efficiency, but which alsoincorporate improved quality of life and are ecologically sensitive.Consumers are now able to choose from a suite of construction materialsthat reduce the environmental impact and resource use. The profusionof “green” roofing products and practices throughout North Americaattests to the predominance of environmental and social concernswithin the industry.

Canada recently ratified its Kyoto Treaty commitment to reducegreenhouse gas emissions. Because Canadian buildings account for 30 per cent of Canada’s energy use and 27 per cent of Canada’sgreenhouse gas emissions, ways to incorporate energy efficiency intobuilding design are being promoted to help meet Canada’s greenhousegas reduction target. In addition, with the increased interest in LEEDand other environmental rating systems, the roofing industry isbecoming more aware that cool roofs and green roof technology areuseful in the Canadian context.

With much of Canada subjected to below-freezing temperatures andsnow, snow load, planting depths, plant choices and vegetationperformance bring unique challenges to our green roof technology.

Building codes and standards in Canada

With the exception of small wood-frame buildings, building codes inCanada do not support specific building technologies. Independentbodies, such as the Canadian Standards Association (CSA), CanadianGeneral Standards Board (CGSB) or the American Society for Testingand Materials (ASTM) International develop standards when there is aneed for specific building technology standards. An ASTM Green RoofTask Force is now working on performance standards for green roofsystems. Municipalities may also choose to adapt the standardsdeveloped by FLL in Germany. In North America, the ASTM, which isdeveloping standards for green roof technology, has already approvedstandards for load determination and growing medium selection.

Most Canadian provinces, territories and municipalities use the NationalBuilding Code of Canada (NBC), researched and developed by the NRCand its Institute for Research in Construction. Municipalities and provincescan make changes to the NBC, but they require significant developmentinvestment. Ontario bases its building code on the NBC for the mostpart and adds specific requirements related to accessibility and retrofitting.

Since the fall of 2005, the NBC has been using objective-based coderequirements. The NBC now bases each requirement on its ability to meetstipulated national performance objectives. Building professionals can meetor exceed these requirements in several ways, using new technologies thathave been evaluated as equivalent to the stated performance requirements.



21

When considering green roof technology the current NBC demandsassessment: of structural loading, roof drainage capacity, waterproofingand warranties, wind protection, fire safety, public accessibility andexit planning. However, it does not prevent the use of green roofs.

Municipalities must consider other regulations. For instance, fire codesgenerally require firefighting or fire prevention capabilities and mitigationto decrease fire risk. Provinces may also have code requirements foroccupational health and safety for workers accessing a roof surface or abuilding’s vertical surfaces (walls that might support a “living wall of plants”).Municipalities may also have bylaws affecting green roof technology, suchas privacy, esthetics, biodiversity, amenity space, green space and so on.

Municipalities may need to consider changing building regulationsrelated to green roof technology. This may require assessment at theNational Building Code level and a long cycle of evaluation. It may besimpler for municipalities to adopt new standards through their ownbylaws. For instance, municipalities may require a building permitbefore green roofs can be installed on existing buildings or they mayhave recommended standards for planting media, depth of media,vegetation cover and maintenance that applicants must follow.

Background — the green roofmovement in Germany

Germany is the world leader in documenting the benefits of greenroofs, advancing the technology and program and developing policy.The Manual discusses the green roof movement in Germany becausethe German experience has significant lessons for Canadian policy makers.

The widespread use of green roofs in Germany can be traced back totwo simultaneous movements in the 1970s — a flurry of technicalresearch to evaluate the ecological benefits of green roofs, and citizenmovements arising from concern for the environment and politicaldissatisfaction.

In the late 70s, researchers started evaluating the ecological benefits ofgreen roofs, inspired by the accidental establishment of plant life on“rental barracks” in Berlin. These working class apartment blocks werebuilt with tar, sand and gravel roofs to prevent the risk of fire. Overtime, plant life established itself, leading to the study of the roof ’secological value.

In 1975 the FLL (Forschungsgesellschaft LandschaftsentwicklungLandschaftsbau e.V. —The Research Society for LandscapeDevelopment and Construction) was established and began to assessconstruction methods for green roofs. Through research, practicalevidence and project implementation the FLL established a set ofguidelines to standardize green roof construction at a high level ofquality.15 (See “FLL guidelines for green roof design, construction andmaintenance,” page 23.)

At the same time, citizen initiatives (Bürgerinitiativen) drew attentionto environmental issues in urban areas. Concerns about increasingurbanization, a lack of green space and a sense of inadequategovernment interest spurred the initiatives. This gave rise to manygrassroots initiatives to bring nature back into the city, such ascourtyard and facade greening and reduction of paved areas. Thispopulist movement gained considerable momentum and gave birth toa powerful political party, the Greens, in the 1980s. 16

The 1980s saw a number of municipal and state incentive programsaimed at bringing nature and green space back into the city. Theseprograms encouraged a variety of urban initiatives, including greenroofs, by subsidizing 50 to 100 per cent of the costs. At least 24German cities offered some type of urban greening subsidy by 1983.These financial incentives were important, as they offset the highercosts of green roof technology. However, as green roofs were morewidely implemented, technology costs fell.17

Germany amended its Federal Building Code (Baugesetzbuch) andFederal Nature Protection Law (Bundesnaturschutzgesetz) in the mid-1980s to include the Ecological Compensation and ReplacementMeasure. This requires that environmental disturbances first be avoided,then minimized and, as a last resort, mitigated. The Measure givesmunicipalities the authority to determine the nature of thecompensation and enforce it through legally binding local developmentplans. Green roofs have become a popular mitigation measure, as theyallow developers to meet their green space requirements.18

15 Köhler, M. & Keeley, M. (2005).The Green Roof Tradition in Germany: the Example of Ber-lin. In Earth Pledge, Green Roofs: Ecological Design andConstruction. New York, New York: Schiffer Publishing Ltd.16 Haan, G. de & Kuckartz, U. (1996). Umweltbewußtsein. Opladen:Westdeutscher Verlag.Köhler, M. & Keeley, M. (2005).The Green Roof Tradition in Germany17 Keeley, M. (2004, June). Green Roof Incentives:Tried and True Techniques from Europe. Presented at the Greening Rooftops for Sustainable CommunitiesConference, Portland, Ore.18 Dürr, A. (1994). Dachbegrünung: ein ökologischer Ausgleich.Wiesbaden: Bauverlag GmbH.Köhler, M. & Keeley, M. (2005).The Green Roof Tradition in Germany



A 1984 federal court ruling requiring transparency in fees for waterwas another other development in green roof acceptance. Until theruling, usage was the sole basis for all water fees for supplying anddisposing of water. In response to the ruling, several municipalitiessplit their waste water fees, separately charging property owners for thestormwater directed to sewers from their property. The fee can rangefrom 0.2 /m2 (30 cents Cdn) to 2 /m2 ($3 Cdn), depending on aproperty’s impervious surface area — including rooftops. To encouragestormwater source control, municipalities offer a discount formeasures, such as de-paving, stormwater retention ponds and greenroofs that keep stormwater out of sewers. Discounts for green roofsrange from 30 to 50 per cent.

The split waste water fee, which follows the “polluter pays” principle,is a successful and well-accepted tool. An estimated half of Germancities with populations of 100,000 or more use split waste water fees.19 The fees are also effective in decreasing the load on sewer systems.

Municipalities are downsizing and eliminating subsidies for urbangreening projects and replacing them with regulations orcombinations of taxes and fees as they deal with tight budgets.

With green roof implementation levelling off, green roof proponentsare looking for new ways to stimulate the market. Two ideas are aquality control system for completed green roofs and a green roof “sealof approval.” Inspecting green roofs after installation is an importantway to ensure that green roofs meet FLL guidelines and theirecological requirements.

Table 5 shows the rate of green roof growth in Germany from 1994 to 2003.

Year 1994 1997 2001 2002 2003

Flat roofs greened(millions of m2)

9 11 13.5 13.5 13.5

Hämmerle, F. (2005). Der Gründachmarkt leidet unterWachstumshemmern. (pre-press)

19 Hämmerle, F. (2004). Personal communication; Keeley, M. (2004, June). Green Roof Incentives

Table 5 — Growth of green roofs, 1994–2003

Soka Bau, Germany



Part 2 — Green Roof policies worldwideIntroduction

The Manual’s national advisory committee selected the jurisdictions in this section because they illustrate unique, successful green roof initiativesfrom different geographic areas, different climates and different phases in the evolution toward green roof policy development.

Policy and programming will be the next step in green roof development across Canada. Much can be learned from other countries. However,Canada’s topography, regionalism and often-harsh winters make green roof technology particularly challenging compared to the Europeanexperience. Research, experience, policy tools, incentives and capacity within the private and public domain are coming together with specific,regional and tailor-made green roof policies.

The appendix has case studies of Calgary, Halifax, Ottawa, Winnipeg, Québec City, Atlanta, Minneapolis-St. Paul, Pittsburgh, Seattle,Washington, D.C. Berlin, London and the state of North-West Westphalia, Germany.

Exchange rates

These are the currency exchange rates as of December, 2005.

Currency Canadian $

British pound — £ $2.03

Euro — € $1.36

Japanese yen — ¥ $0.009

Singapore dollar — $ $0.69

Swiss franc — CHF $0.88

U.S. dollar — $ $1.15

23

Canada United States International

Montréal Chicago Basel-City, Switzerland

Toronto New York Münster, Germany

Vancouver Portland Singapore

Waterloo, Ont. Stuttgart

Tokyo



Canada

DescriptionMontréal, in southern Quebec, is Canada’s second largest city. It has very cold winters,hot summer periods and a fair amount of rainfall throughout the year and heavysnowfall in the winter months. Geographically, it is on an archipelago where theOttawa and St. Lawrence Rivers meet.

One of the oldest cities in North America, Montréal is one of Canada’s leadingcommercial, industrial and service centres. The metropolitan area has a populationof over 3.5 million.

Montréal has a northern climate, with temperatures that range from -40°C (-40ºF)to 40°C (104ºF).

Harmonization of the built environment with the low-rise, multi-family characterof the low-lying areas around the city’s Mount Royal that seems to be driving thecurrent interest in green roofs. In some ways, this esthetic consideration is similarto the drive for green roofs in Singapore, although in Montréal the buildings arepredominantly low-rise wood construction.

GREEN ROOFS POLICIES WORLD WIDE

Case studies

Montréal, Quebec

Key motivators Energy efficiency, urban agriculture

Policy phase 5 — Program and policy development

Champion Multi-sectoral

Longitude 46ºN Latitude 74°W

Average summertemperature

21°C(70ºF)

Average wintertemperature

-10°C (14ºF)

Averageannual rainfall

760 mm (30 in.)

Average annualsnowfall

2,142 mm (84 in.)*

*The depth of snowfall does not necessarily provide a good indicator of the amountof equiva-lent rain, as snow compacts over time. For example, in Montréal the totalannual precipitation including rainfall and snowfall is 967 mm (38 in.)

Heat Island EffectInfra red scan of the Island of Montreal - lightercolours represent cooler areas, such as the MountRoyal Park in the centre of the island.

Map showing Montreal and Quebec City, QuebecScale 1:4,000,000


Green Roof pol ic ies worldwide—Montréa l

Montréal has also considered green roofs foragriculture. Universities in Montréal andQuébec City have initiated research related toplants on green roofs and urban agriculture.

Elements of policy phases 2 to 5 are evidentin Montréal. So far, implementation of greenroofs in Montréal has been sporadic. Howeverrecently the work done by the Urban EcologyCentre, a non-profit organization, issucceeding in bringing many stakeholders,including municipal officials, together.The official City Master Plan now containsspecific language related to green roofs.

There is a direct incentive program, of $5a square foot towards green roof installation,offered by the Quebec Energy EfficiencyFund. Gaz Métropolitan (the gas utility),provides the funding. Green roofs areconsidered to have the potential to reduceenergy consumption in buildings. Therewas apparently no calculated basis for the$5/ sq. ft. (about $54/m2) incentive. Thesubsidy is the first of its kind in Canada.

Gaz Métropolitan has also supported aresearch project by NRC and EnvironmentCanada to model energy savings fromgreen roofs.

Key motivatorsThe key motivators for green roofimplementation are an interest in thebenefits of energy efficiency, because of theclimate extremes and the use of green roofsto provide urban agriculture opportunities.Other identified motivators includestormwater runoff, urban heat islandeffects and air quality.

An incentive for Montréal is the desire togreen the asphalt roofs of the city’s typicallow-rise, multi-family housing.

Description of policyMontréal has undertaken policy workrelated to phases 1 to 4 and is consideredto be in the preliminary stages of phase 5.However, more work is needed forcommunity engagement and technicalresearch before fully embarking on programand policy development in phase 5.

There are currently no stated municipalpolicies relating to green roofs althoughThe Plateau (a borough of Montréal) isconsidering requiring new municipalbuildings to have green roofs.

The Montréal Master Plan identifies twoareas where green roofs can meet thestated ob-jectives:

� Objective 17: ensure the optimalmanagement of resources in an urbancontext, which is part of the goal forhealthy environment. This objectivecan be achieved by developing andimplementing incentives to improveenergy efficiency standards and byapplying innovative techniques, such asgreen roofs for new construction andexisting buildings.

� Objective 12: promote qualityarchitecture and consolidate the builtenvironment in harmony with thesurrounding character. This objectivecan be achieved by developing andimplementing incentives to encouragethe integration of energy-efficientmethods and environmentally sensitivearchitectural innovations, such as greenroofs, in new construction orrenovation projects

Additionally, the municipal governmentsupports initiatives related to green roofssuch as partial funding of a demonstrationroof by the Urban Ecology Centre (UEC)and the funding of a symposium on greenroofs organized by Green Roofs forHealthy Cities.

Demonstration projectand grass roots movement

In the summer of 2005, the UrbanEcology Centre (UEC) built ademonstration project on the roof of theCoopérative la petite cité at 3518, rueJeanne-Mance, a flat-roofed duplex in theMilton-Parc neighbourhood.

For information about this project seehttp://www.ecosensual.net/drm/portfolio/projetpilote1.html. Retrieved November,2005. French. In early 2006, they alsoinitiated a second and larger green roofconference to increase awareness of greenroof benefits among policy makers,industry and the public.

In February 2005, the UEC published itsGreen Roof Report, with informationabout green roofs in the context ofMontréal.



27

Green roof awarenessThe City of Montréal was co-host of agreen roof symposium with Green Roofsfor Healthy Cities in November 2004, with100 participants. Following the symposium,Montréal established a Green Roof Committeeto investigate ways to promote green roofs.

In other green roof activities, two localsuppliers of green roof systems, Hydrotechand Soprema, have researched green roofsystems in Quebec through work by localuniversities. In addition, Marie AnneBoivin, through Soprema, has doneextensive work on growing medium andplant selections for the Canadian climate.

The impact of green roofs on firefighting isa unique issue in Montréal. Currently,Montréal firefighters cut an opening in theroof of a wood-frame building to ventsmoke. The fire department was concernedthat green roofs will slow their efforts in afire. This concern has been resolvedthrough the development of the UECdemonstration roof and discussion amongstakeholders.

EffectivenessThe language in the Montréal Master Plansuggests that green roof awareness isgrowing in Montréal. It is becomingrecognized at the political level as well.

Under the incentive offered by the EnergyEfficiency Fund, there were three projectsap-proved in the first three years of theprogram. As more people become aware ofthe pro-gram, more projects may takeadvantage of the incentive.

As awareness of green roofs increases, moreprojects are expected. The headquarters ofCirque du Soleil is an example of onerecent large local development with a greenroof. There have been others, mostlyinstitutional projects, such as the newaddition to the École Polytechnique (U deM engineering school), the retrofit at theFaculté d’aménagement (U de M landscapearchitecture school), the Québecheadquarters of the RCMP in St-Henri,and the Châteauguay library. McGillUniversity is planning two projects that willhave green roofs.

UEC is helping to solve issues related togreen roofs as retrofit measures onresidential buildings. The UEC has beeneffective in bringing the City of Montréal,the roofing supply industry, the roofingindustry, fire services, media, EnvironmentCanada, Environnement Québec, the NRCand local residents together. TheAssociation de maîtres couvreurs duQuébec (AMCQ), the Québec RoofersAssociation, documented construction ofthe UEC demonstration project to publisha technical bulletin.

PredictionsIn Québec, the Agence d’efficacitéénergétique has recently increased theincentive for green roofs to $5/sq. ft. Alongwith the information products and recentactivities of the Urban Ecology Centrediscussion, action on green roofs willcontinue to increase in Montréal.

The UEC believes that the newdemonstration roof, along with grass roots movements, will result in:

� Completion of research on green roofson wood-frame construction tounderstand the necessary fire, structuraland architectural interventions that maybe needed and benefits that may accruefor buildings in Montréal.

� Organization of education programs topublicize the benefits of green roofs.

� Identification of costs and benefitsrelated to green roofs.

� Collaboration amongst stakeholders infurthering green roofing.

� Encouragement by the City ofMontréal and other levels ofgovernment to implement a green roof

subsidy program and green roofrequirements in building regulations.



Key literatureFotopulos, H. (2005, May 19). Protecting our Trees. Montréal Mirror 20 (27). Retrieved June 2005, fromhttp://www.montrealmirror.com/2005/051905/letters.html

Lamey, M. (2004). Going Green on Top. Montréal Gazette (Dec. 18, 2004). Retrieved fromhttp://www.urbanecology.net/GRED/Archive/going_green_on_top.htm

Lamey, M. (2005). It's not easy being green. Montréal Gazette, page E1 (Aug. 27, 2005).

Landreville, M. & Rose, O. (2005). Tortures vertes à la montréalaise: Rapport de recherche sur l'implantation des toits verts àMontréal. Montréal: Urban Ecology Centre-Sodec.

Laroche, D., Mithcell , A.-M. & Peloquin, S. (2004). Les toits verts ajourd'hu; c’est construire le Montréal de demain - Memoireprésenté a l'office de consultation publique de Montréal dans le cadre du nouveau plan d'urbanisme 2004. Retrieved fromhttp://www2.ville.montreal.qc.ca/ocpm/pdf/41/8aa.pdf

Léger, Marie-France. (2005). Se mettre au vert. en ville. La Presse, page I3. (July 16, 2005). Opt for a Green Roof! Financial incentiveprogram to encourage urban green roof installation. (n.d.). Montréal, Quebec: Energy Efficiency Fund Office. Retrieved fromhttp://www.fondsee.qc.ca/en/pdf/Programmes_commercial/CII%20Toiture%20vegetale%20Ang.pdf

Rabinowicz, J. & Hautecouer, I. (2004). Rooftop gardening, liberating spaces for healthier cities. Montréal, Quebec: Alternatives &Santropol Roulant. Retrieved from http://www.santropolroulant.org/images/4pp-EN-2004-5.pdf

Urban Ecology Centre. (2004). Green roofs a la montrealaise - A demonstration project. Retrieved fromhttp://www.urbanecology.net/GRED/Archive/Green%20Roof%20project%205-10-04.doc

Ville de Montréal. (n.d.). Master Plan, Action 17.1. Retrieved from http://www2.ville.montreal.qc.ca/plan-urbanisme/en/plan_urbanisme/2_3/chap2/2_7/obj17/page3.shtm

OUR WEBSITE ADDRESS: www.cmhc.ca

Although this information product reflects housing experts’ current knowledge, it is provided for general information purposes only. Any relianceor action taken based on the information, materials and techniques described are the responsibility of the user. Readers are advised to consultappropriate professional resources to determine what is safe and suitable in their particular case. Canada Mortgage and Housing Corporationassumes no responsibility for any consequence arising from use of the information, materials and techniques described.

09-05-06

Contact information

Marie Anne BoivinSoprema(450) [email protected]

Manon LacharitéQuebec Energy Efficiency Fund(514) 598-3344www.eefund.gc.ca

Lucia KowalukUrban Ecology Centre(514) 282-8378

Owen RoseMontréal(514) [email protected]

DescriptionToronto is the fifth largest city in North America, with a population of 2.54million. It is part of the Greater Toronto Area (GTA), the largest metropolitan areain Canada, with a population of 5,203,686 people. The GTA includes four regionalmunicipalities with 15.9 per cent of Canada's and 41.8 per cent of Ontario'spopulation. Major transportation routes and rail lines connect Toronto to othereconomic centres and the city is a short drive from other densely populated urbanareas to both the east and west. Toronto is an economic hub within Ontario.

Toronto's climate is among the mildest in Canada and is comparable to that ofNew York or Chicago. Toronto receives less snowfall than other cities in Canadabut winter temperatures can stay below freezing for extended periods.

With little or no protective snow cover, plant choices for green roofs can be a challenge.Over the last five years, Toronto has shown significant leadership in research thatsupports the environmental benefits of green roofs. Currently, there are two fullyinstrumented green roofs (and a third one planned) that contribute to the compilationof local data on the stormwater and energy benefits of green roofs. These attributes,as well as strong multi-sectoral support for green roof policy development, positionToronto in phase 5 in the evolution of policy development. In 2005-2006, Torontowill start developing programs and policies supporting the implementation ofgreen roofs.


Case studies

Toronto, Ontario

Key motivators Stormwater management and air pollution

Policy phase 5 - Program and policy development


Longitude 79°24' W Latitude 43°40' N


26°C (79°F)


-2°C (28°F)


68.9 cm (27 in.)


135 cm (53 in.)

Map of Toronto

Green roof Toronto City Hall


Green Roof pol ic ies worldwide—Toronto

Toronto has a unique ecosystem, boundedby Lake Ontario in the south, the NiagaraEscarpment in the west and the OakRidges Moraine in the north. The GTA ispart of the Greater Toronto Bioregion, alarger, natural ecosystem. Several watershedsdrain into Lake Ontario and provideimportant biodiversity and aquatic habitatswithin the city limits. Toronto is thenorthern extent of the Carolinian forestzone in Ontario.

Lake Ontario moderates Toronto's climate,which is among the mildest in Canada.Toronto receives significantly less snowfallduring the winter than most other Canadiancities and winters tend to be mild. However,in recent years winter temperatures havebeen more variable, with daytime high

temperatures averaging just a few degreesbelow freezing (there are often two or threecold snaps each year). A typical snowfall isno more than 10 cm (4 in.).Toronto doeshave heat waves, usually coupled with highhumidity and smog alerts, withtemperatures above 32°C (90°F), but theygenerally last no more than a couple of days.

Key motivatorsThe key motivators for the City of Torontoare reduction of stormwater runoff,especially in areas overflow of combinedsewers; reduction of urban heat island effectand replace-ment of displaced green spaces.

Description of thepolicyToronto has demonstrated solid leadershipin green roof technology and green roof re-search over the past five years. Toronto isdeveloping programs and policies to supportimplementation of green roof technologythroughout the GTA. A cost-benefit analysiscompleted in 2005 will contribute to theformation of new policy.

Process to establishpolicy The city's involvement in green roofs goesback to the recommendations of the 2001en-vironmental plan, which first identifiedthe need for a strategy to encourage greenroofs and rooftop gardens. The naturalenvironment policy within the city's newofficial plan supports “the development ofinnovative green spaces such as green roofsand designs that will reduce the urban heatisland effect.”

The Wet Weather Flow Management MasterPlan for Toronto, completed in 2000, examined ways to improve the water qualityof local rivers and Lake Ontario bystrengthening mechanisms to prevent andreduce stormwater runoff. Green roofs mayappear in future stormwater-planning policies.

A Toronto Green Roof Feasibility Study,completed in 2000, provided support for ateam to move forward with two green roofdemonstration projects - one of 557 m2

(6,000 sq. ft. on Toronto City Hall PodiumRoof and the other, 650 m2 (7,000 sq. ft.),on Eastview Community Centre roof at 86 Blake St. Launched Nov. 2, 2000, theToronto City Hall Green RoofInfrastructure Demonstration Project is aprivate-public partnership of the City ofToronto, the Toronto Atmospheric Fund,Green Roofs for Healthy Cities, the NRC'sInstitute for Research in Construction andEnvironment Canada. The cost, whichincluded re-roofing, was about $260,000.

The investment in the EastviewCommunity Centre re-roofing and greenroof was $274,000. The federalgovernment's Technology Earthly ActionMeasures (TEAM), the City of Toronto,NRC, Environment Canada, the TorontoAtmospheric Fund and Green Roofs forHealthy Cities supported the project.

Figure 7 - Views from extensive green roof (planted in June, 2004) at The RobertsonBuilding, 215 Spadina Ave,Toronto. Urbanspace Property Group of Toronto owns andmanages the Robertson Building.

Charrette design showing proposed greenroof as part of supportive housing extensionin Toronto



31

The objective was monitoring and evaluatingthermal performance and otherenvironmental benefits.

The First International Green RoofWorkshop on Establishing CommonProtocols for Building and Aggregate LevelGreen Roof Benefits Research took place inToronto in 2000.

Toronto Public Health, the TorontoAtmospheric Fund and the Climate ChangeAction Fund sponsor “Cool Toronto.” Theobjective is to protect Torontonians from thenegative impacts of extreme summer heatand to develop programs to reduce summertemperatures. Cool Toronto and the UnitedStates Environmental Protection Agency(EPA) were co-hosts for a North Americansummit May 2-4, 2002, to examine ideas tomanage urban heat island. At the June, 2004Smog Summit, Toronto - in partnership withthe Centre for Research in Earth and SpaceTechnology (CRESTech) - announced a$40,000 grant from the Federation ofCanadian Municipalities (FCM) GreenMunicipal.

Enabling Fund to study municipal costsavings benefits of green roofs completed in2005. The study provided measurable costsand benefits of green roofs within the city,quantify potential money savings, identifiedthe projected time for cost recovery; andidentified minimum threshold points forproviding incentives.

CRESTech conducts multidisciplinarycollaborative research and development inspace and earth sciences. A consortium ofuniversity-based researchers, industryleaders and government, CRESTech iscommitted to bridging the gap betweenpure science and the successful applicationof science and technology in profitable newbusinesses.

In 2005, Toronto was also the host for arainwater harvesting workshop and charettesupported by CMHC, in which green roofsplayed a potential role.

Following the 2005 cost-benefit study, theCity's planning department presented adiscussion paper Making Green RoofsHappen to its advisory Roundtable on theEnvironment. This paper was based on thefindings of Stakeholder Workshops, theCity's study The Environmental Benefitsand Costs of Green Roof Technology andinformed by an early draft of this manual.

The options that were put forward forconsideration by the Roundtable include:

� Subsidies or grants

� Green loans

� Pilot retrofit grant program

� Regulations requiring that a newbuilding not increase stormwater flowfrom a site

� Rebate in water or energy rates to offsetongoing costs

� Introduction of a StormwaterManagement Charge with forgivenessaccording to stormwater managementmeasures achieved on site

� Encourage developers to install greenroofs by

� Offering density bonuses

� Qualifying green roofs as parklanddedication

� Improving approval procedures

� Training of city permits staff

� Encouragement of the province toamend the Building Code to facilitate“green technologies”

� Integrate green roofs into the City'snew Green Development Standards.

� Include green roofs as Stormwater BestManagement Practice in CityGuidelines

� Educate different audiences about thebenefits of green roofs

As of March 2006, the City has adoptedthe criteria for a Green Roof Incentive PilotProgram, which offers a grant of $10 Cdn.per square metre ($ 0.93/sf ) of eligiblegreen roof area, up to a maximum of$20,000. The eligible green roofs must:

� Cover any size or type of heatedbuilding space, with the roof above grade

� Be intensive or extensive

� If new, have a minimum growingmedium depth of 6”

� If retrofitted roofs, have a minimumgrowing medium depth of 3”

� Have a maximum slope of 10%

Applicants are required to show:

� At least 50% coverage of the building'sroof footprint

� Mixed vegetation rather thanmonoculture

� Maximum runoff coefficient of 50%



EffectivenessSome of the green roofs in the GTA:

� York University, Toronto, installed a2,787 m2 (30,000 sq. ft.) green roof onthe Computer Sciences Building as partof York's Greening Initiative.

� Ryerson University's engineering buildingset up a 743 m2 (8,000 sq. ft.) green roofin 2004.

� In 2000, the Merchandise Building, acondominium unit in downtownToronto, built a 929 m2 (10,000 sq. ft.)intensive green roof with accessiblepublic path-ways, decks and eight gardenbeds. The building is a formerdepartment store.

� One of the oldest green roofs in Torontobelongs to Mountain Equipment Co-op.Built in 1998, the roof is about 604 m2

(6,500 sq. ft.).

� Earth Rangers Centre, in Woodbridge(north of Toronto) is a leading education,wildlife rehabilitation and research centre.It has a 1,394 m2 (15,000 sq. ft.) greenroof that is expected to reduce energycosts, reduce stormwater runoff andimprove air quality.

� The University of Ontario (formerlyDurham College) in Oshawa, about 40km (25 mi.) east of Toronto, installed a836 m2 (9,000 sq. ft.) green roof in 2004.

Lessons learnedThe City of Toronto has gained valuableinsight into the environmental costs andbenefits attributed to green roofs through theMunicipal Cost Savings Benefits Study onGreen Roofs and from well-establishedpartnerships with green roof researchersacross Ontario. The Eastview and YorkUniversity green roof demonstrations haveprovided valuable lo-cal sources ofinformation on the effectiveness of greenroofs in Toronto for managing stormwaterand thermal and energy savings.

PredictionsBased on the findings of the Municipal CostBenefits Study on Green Roofs, the City ofToronto's Round Table on the Environmentwill recommend ways to promote green roofsthat will go to Council in early 2006.Toronto has also started preparing greendevelopment standards to guide privatedevelopers and construction of city-ownedbuild-ings. The standards will focus on thecity's objectives for reducing energy andwater consumption, stormwater runoff,urban heat island effects and promote therestoration and conservation of the naturalheritage system. 22

Toronto City Hall green roof overparking lot.

22 For more information, seewww.toronto.ca/greenroofs RetrievedNovermber, 2005. English.



33



09-05-06

Contact information

ContactsJoe D'AbramoCity of Toronto (416) [email protected] John MinorCity of Toronto (416) [email protected] Jane WelshCity of Toronto (416) [email protected]

LiteratureAkbari, H.,& Konopacki, S. (2004). Energy effects of heat-island reduction strategies in Toronto, Canada. Energy, 29, 191-210.

Bass, B., Stull, A., Krayenhoff, S.,& Martilli, R.B. (2002). Modeling the Impact of Green Roof Infrastructure on the Urban HeatIsland in Toronto. The Green Roof Infrastructure Monitor. 4 (1).

Bass, B., Krayenhoff, S., Martilli, A., Stull, R.B. & Auld, H. (2003, May). The Impact of Green Roofs on Toronto's Urban HeatIsland. Presented at the Greening Roofs for Sustainable Communities Conference, Chicago .

Currie, B.A. (2005). Air Pollution Mitigation with Green Roofs Using the UFORE Model. Unpublished MASc. thesis, RyersonUniversity, Toronto, Ont.

Liu, K. & Baskaran, B. (2003, May).Thermal Performance of Green Roofs through Field Evaluation. Presented at the GreeningRooftops for Sustainable Communities Confer-ence, Chicago.

Liu, K. & Minor, J. (2005, May). Performance Evaluation of an Extensive Green Roof. Presented at the Greening Rooftops forSustainable Communities Conference, Washington, D.C.

Ryerson Quad green roof over library


DescriptionVancouver is in a temperate rainforest influenced by the Pacific Ocean on itswestern border. Water surrounds the city on three sides and the Coast MountainRange, with peaks above 1,500 m (4,920 ft.), in on the fourth side. High-risedwellings dominate Vancouver's densely packed city core.

Local governments in B.C. have recognized that stormwater-related problems canbe avoided by designing and building communities that capture rainfall at sourceand restore it to natural hydrologic pathways.

As the key objective in Vancouver is to reduce the total impervious area within thecity limits, green roofs fall under a broad and sustainable stormwater managementplan in the Greater Vancouver Regional District (GVRD). The recent StormwaterSource Controls Design Guidelines highlights green roofs as a tool for stormwatercontrol. Vancouver is expected to be a strong contributor to Canadian green roofleadership. The BC Institute for Technology (BCIT) opened a Green Roof ResearchFacility in 2004. The City and the GVRD are embarking on programs and policiesthat support awareness and use of green roofs, which places Vancouver at phase 5 in policy development.

The population of downtown Vancouver is approximately 560,000 and the GVRDabout two million. Covering about 113 km2 (43 sq. mi.),Vancouver is the largestport on the west coast of North America, the largest city in B.C. and the thirdlargest city in Canada.


Case studies

Vancouver, BC

Key motivators Stormwater runoff, urban heat island reduction, publicamenity space

Policy phase 5 - Program and policy development


Longitude 123°07' W Latitude 49°17' N


18°C (64°F)


3°C (37°F)


121.9 cm Average annualsnowfall

—

Map of Vancouver


Green Roof pol ic ies worldwide—Vancouver

35

Key motivatorsMany local governments in B.C. haverecognized that they can avoid stormwater-related problems by designing andbuilding communities that capture rainfallat source and re-store it to naturalhydrologic pathways. Stormwater issuesare a particular problem where buildingsare built on steep slopes that havedifficulty retaining soil from water runoff.

Description of policyThere is no direct policy supporting greenroof development in Vancouver, but thecity is exploring ways of implementinggreen roofs.

In the Southeast False Creek (SEFC) area,a brownfield site, the city is pursuingdevelopment of about 60 acres of mixed-use development as a model, sustainablecommunity. The City has required that allbuildings obtain LEED certification. Partof this site will be home to the 2010Olympic Village and constructioncompleted for that event. Intensive andextensive green roofs will be part of thegreen building elements and will help toimplement the City’s targets with respectto pervious land area of 60% andamenities in this new neighbourhood.

In July, 2004 Council approved a greenbuilding program report that asked staff towork on the development of a city-widegreen roof strategy. As the first phase ofthis strategy, Council adopted a greenbuilding strategy as a baseline for alldevelopment in SEFC. The officialdevelopment plan for SEFC (March,2005) ensures that all buildings will have aminimum of 50 per cent green roofs, withthe roof built to a structure and capacity(including health and safety and access-egress) to support intensive green roofs.

While these may be planted as extensiveroofs, they will have the capacity tosupport transformation to intensive spacesat the discretion of future owners. An IDPworkshop was held in April 2006 to alignthe City and the Olympic Villagedeveloper in support of their greenbuilding agenda.

Additionally, Vancouver is embarkingupon a city-wide green building strategythat will change bylaws and coderequirements for all development, makingthe city baseline a “green” baseline. Greenroofs will play a role in this strategy.

The city wants to make green buildingsand green roofs a provision of new bestpractices for development and does notforesee incentives or bonuses as a tool forimplementation. The city may usesecondary tools to encourage green roofs,such as negotiations for amenity throughrezoning or through development costcharges, if water and sewerage moves to ametered basis. It is not consideringbonuses for height or density, followingextensive studies on view corridors, urbandesign and the public realm. Additionalheight and density would have adverseaffects on many of these key issues.

Other policy considerations in Vancouverinclude building management elements,such as:

� a commitment to maintain the greenroof for the life of the building

� a fire prevention program

� a green roof data inventory

� some monitoring for environmentalperformance

� a commitment to sharing lessonslearned.

Because of Vancouver's temperate climate,property owners have used green roofs toprovide additional urban amenity space.The adequate supply of rainwater and theen-hanced humidity have helped intensiveand extensive green roofs thrive over theyears. Many visitors notice thespontaneous appearance of moss (nature'sown extensive green roof ) on the surfacesof many sheds and garages.

Process to establishpolicyBCIT launched the Green Roof ResearchFacility (GRRF) in 2004. The 100 m2

(1,076 sq. ft.) building is dedicated toresearch on stormwater source control andthermal performance of green roofs. Thisinformation will be used to create andsupport installation and design guidelinesand for policies and programs supportingthe broad implementation of green roofsin the GVRD.

Over the past two years, the StormwaterSource Control Design Guidelines havehelped the GVRD examine the costs andbenefits of different regulatory options tomanage stormwater. The Guidelines featurethe major landscape design guidelines toimprove stormwater runoff quantity andquality, such as absorbent landscapes, bio-retention facili-ties, vegetated swales,pervious paving, infiltration trenches andextensive green roofs. The Guidelinesdevote several pages to green roofs,

Downtown Vancouver



including a description, rationale,applications, limitations, types, guidelinesand recommended design criteria tomaximize the environmental benefits ofgreen roofs.

This report is part of the Region's LiquidWaste Management Plan (LWMP) toimplement integrated stormwatermanagement planning for all developingwatersheds. A LWMP approved by theprovincial minister of water, land and airprotection under the Waste Management Actmay replace the more prescriptiveregulations contained in the municipalsewage regulation. A stormwaterinteragency liaison group (a commitmentin the LWMP) helps develop tools, such asthe Guidelines.

Given the unique objectives, needs andpriorities of each GVRD municipality,these stormwater guidelines neitherrecommend nor prescribe one particularstormwater management option. Instead,municipalities contemplating bylawchanges can use the Guide-lines as areference for more detailed, site-specifictechnical and legal investigations of possiblechanges to their bylaws.1

EffectivenessIn 2002, the GVRD commissioned thefirst green roof inventory for the region.The inventory proved challenging andbeneficial as a tool for professionals andmunicipalities in developing green roofpolicy, planning and education. It not onlyillustrated the types, numbers anddistribution of green roofs in the region,but it also helped to determine their impacton development.

The inventory focused on all types of largebuildings in the urban core and municipalcentres. Aerial photographs, contactinglocal professionals and visits to local sitesidentified nearly 550 buildings, with 278recognized as garden roof decks, over 30categorized as extensive green roofs andthree as semi-intensive green roof systems.

Significant buildings with green roofsinclude the Vancouver Public Library, theVancouver Court House, the WaterfallBuilding, the White Rock Public WorksBuilding and the Fairmont WaterfrontHotel (urban agriculture). Other currentprojects include the Seymour-CapilanoFiltration plant and the VancouverConvention Centre. The conventioncentre, when completed in 2008, will bethe largest green roof in Canada with 2.4hectares (6 acres) of flowers and grasses.The centre will be the media and broadcastcentre for the 2010 Winter Olympics andits design and green roof are a response tothe sustainable goals for the Games.

Lessons learnedOne benefit of the green roof inventory wasthe recognition of perceptions and barriersaffecting the region's green roof industry.Historically, garden roofs were included foresthetics and recreational purposes;

however, green roofs are now installed foreconomic and environmental purposes.While stormwater management was a keymotivator for municipal governments inthe region, the adoption and pursuit of aSilver or Gold LEED certification has beencited as the impetus for many new andprospective green roofs.

Some general misconceptions discoveredduring the inventory have helped to definethe need for the next phase of green roofeducation and awareness in the GVRD. Forexample, respondents indicated that theybelieved that green roofs ends to leak, thatthey hold water on the roof, which causesmembrane failure, that they are associatedwith Vancouver's leaky condominiumproblem and that both the upfront andmaintenance costs are prohibitivelyexpensive.

For more information see:http://www.betterbuildings.ca23

PredictionsLocal performance data and a commitmentto ongoing research in the GVRD arecontributing to an expansion of trainedprofessionals with specific knowledge of

green roofs. They are helping to build anddistribute design guidelines formunicipalities to use as developmentoccurs. Green roofs are part of the GVRD'soverall commitment to sustainabledevelopment and green building. Thepursuit of LEED certification has been theimpetus for many green roof projects in theregion and is expected to spur furtherimplementation of green roofs.

23 Retrieved November, 2005. English.



37

Key literatureConnelly, M. & Liu, K. (2005, May). Green Roof Research in B.C. - An Overview. Presented at the Greening Rooftops forSustainable Communities Conference, Washington, D.C.

Davis, K. & Kim, M. (2003, May). Vancouver's Green Roof Inventory and Next Steps. Presented at the Greening Rooftops forSustainable Communities Conference, Chicago .

Greater Vancouver Regional District. (2004). Stormwater Reports. Retrieved April 20, 2005, fromhttp://www.gvrd.bc.ca/sewerage/stormwater_reports.htm

Johnston, C., McCreary, K. & Nelms, C. (2004, June). Continuous Flow and Temperature Runoff Monitoring of a Green Roof in thePacific Northwest. Presented at the Greening Rooftops for Sustainable Communities Conference, Portland.

Oberlander, C., & Whitelaw, E. (2005, May). Aesthetic Design and Green Roofs. Presented at the Greening Rooftops for SustainableCommunities Conference, Washington, D.C.



09-05-06

Contact information

ContactsMaureen ConnollyDirector of Green Roof [email protected] Kim, P. Eng. Senior Project EngineerPolicy and Planning DepartmentGVRD(604) [email protected]

Dale MikkelsenProject PlannerCity of Vancouver(604) [email protected]

Vancouver library in accessible green roof viewed from surrounding buildings.

DescriptionAn “Environment First” philosophy gives the City of Waterloo a direction that willnaturally lead to the promotion of green roofs and most likely to the creation of agreen roof policy. This philosophy evolved from a city-wide visioning exercise calledImagine! Waterloo and has resulted, among many other projects, in a Green RoofsFeasibility Study and the construction of a demonstration green roof. These actionsplace the city in phase 4 Technical Research, of green roof policy development.

Stormwater control is the key driver for the city and it is considering innovativeways to manage the runoff, such as impervious surfaces and a stormwater utility .The citizens of Waterloo have identified improved air quality as their key driver toencourage green roofs. The city recently convened a steering committee of surroundingcommunities to work together to consider the development of a green roof policy.Waterloo is an example of the importance and benefit of engaging the entirecommunity in planning. Political will and community support, combined with theCity’s moderate climate in southwestern Ontario, will advance the development ofgreen roof policy.

Situated on the banks of the Grand River in the heart of southwestern Ontario,the City of Waterloo, population 110,800, is surrounded by agricultural land withfragmented forest systems (13 per cent forest cover). Three-quarters of the city’swater supply is drawn from groundwater; the remainder from the Grand River.


Case studies

Waterloo, Ont.

Key motivators Stormwater control and air quality

Policy phase 4 — Technical research

Champion Municipality

Longitude 80º30’W Latitude 43º30’N


80º30’WAverage wintertemperature

-11.4°C (52°F)


917 mm(36 in.)


158 cm (62 in .)

Map of Waterloo


Green Roof pol ic ies worldwide—Water loo

39

Waterloo has a moderate climate withsimilar temperatures and precipitation asToronto. It has two major universities —the University of Waterloo and WilfredLaurier University.

Key motivatorsStormwater control is the key driver forthe city, but Waterloo residents identifiedair as the main concern in the Imagine!Waterloo visioning exercise.

Description of the policyThere is no specific policy encouraginggreen roof construction, but the city isconsidering several ideas, such as astormwater utility charge on theindustrial, commercial and institutionalsector for stormwater treatment.Neighbouring jurisdictions are interestedin joining Waterloo on this initiative.Buildings with a green roof will pay areduced fee. This idea is several years fromreality but appears to be feasible and thereis the political will to make it happen.

There are also restrictions on impervioussurfaces in some residential areas,providing another way to reducestormwater runoff.

Process to establishpolicyWaterloo adopted its Environment Firststrategy and philosophy in 1989 to ensurethat environmental matters are assessed atthe forefront of all its business activities .

The results of the community-widevisioning exercise Imagine! Waterloo,served, among many things, to reconfirmthe City’s high priority for preserving the

natural environment. Air quality, waterquality and access to natural areas are keyquality-of-life indicators for the future.

In 2001, building on existingenvironmental management capabilities,the City of Waterloo then identified theneed for an environmental strategic planand formed the Mayor’s EnvironmentalTask Force. The task force developed 24strategic actions linked to Imagine!Waterloo and included ways to worktowards environmental improvements forair and water quality, green spaces,planning and growth, energy and naturalresources, and stakeholder awareness. Eachaction provides high-level direction onenvironmental protection andenhancement goals.

The Task Force identified six keyenvironmental areas and defined strategicactions. The six areas are:

1. planning and growth

2. water resources

3. air quality

4. energy and resources

5. environmental awareness

6. reen space.

Green roofs fit into the environmentalstrategic plan in most of these areas, mostnotably under planning and growth, airquality and water resources.

There are four strategic actions inplanning and growth

1. enhance existing policy

2. consider new policy and regulations

3. establish a development forum

4. enhance technical considerations inplanning and urban design.

Green roofs fall under the last action. TheEnvironmental Strategic Plan states that“urban design needs to consideropportunities for new environmentaltechnology” and includes green rooftops inthe list of examples. Green roof initiativescould also be incorporated under thestrategic action of considering new policyand regulations. For example, in thefuture, the City of Waterloo may consideradding a requirement to all newdevelopments that green roofs be a part ofnew buildings, or at least considered.

Strategic actions considered under airquality include reducing externalpollution, such as trans-boundarypollution; reducing local pollutants,primarily vehicle emissions; identifyingsources of air pollution; and, reducing theurban heat island effect.

Green roofs can play a significant role inreducing the urban heat island effectbecause they reduce the area that absorbssolar radiation as heat. They also cool thesurrounding air through evapo-transpiration.

Phase II of the Environmental StrategicPlan implementation directly incorporatesboth actions that consider green roofs.Phase II is expected to take place from2005 to 2008 in three phases. The firstphase includes actions that can be easilyimplemented or that amplify existing Cityinitiatives and show immediateenvironmental benefits. Items designatedfor Phase II may require additionalresources to what currently exists,including additional lead-time for planningand implementation. Other areas wheregreen roofs could fit into the



Environmental Strategic Plan include waterresources and energy and resources; the firstbecause of the stormwater managementbenefits that green roofs provide and thesecond because of the energy-efficiencybenefits. Waterloo's Environmental StrategicPlan is a useful document in providingguidance and helping to set priorities foraction on environmental health andprotection in Waterloo in the future. Giventhe strategies and goals in the EnvironmentalStrategic Plan, green roofs can play a role inimproving the overall environmental healthof the City of Waterloo.

As a result of the Environmental StrategicPlans and the identified potential of greenroofs to meet many of the identified goals,the city applied to the Federation ofCanadian Municipalities (FCM) for $25,000through their federally-funded GreenMunicipal Funds for a green roofs feasibilitystudy and green roof demonstration site ona city-owned building.

With matching dollars from the city, thefeasibility study was conducted to identifywhich of their municipal buildings wouldbe most suitable for green roofs. The studyalso discussed the types of green roof andtheir advantages, the costs of installationand maintenance as well as the long-termplanning required.

The intent of this feasibility study was toidentify the municipal buildings mostsuitable for a green roof. The analysisdetermined the advantage of a green roofand construction and maintenance costs.The study also determined the potential forgreen roof systems in Waterloo andidentified existing opportunities.

The report is intended as a tool to guidedecision-making process for the city's buildingroof maintenance or new building and

facility projects. More specifically, this reporttells the City the best places to apply greenroof technology and outlines the benefits.

The study consolidated relevantinformation already available from Europeand North America, supplemented theinformation with additional data yet to becollected then produced a Waterloo-oriented analysis. It provides an accuratepicture of green roof applications inWaterloo including the required long-andshort-term planning.

Construction of an accessibledemonstration green roof began in the fallof 2005 on City Hall , which also raisesawareness of green rooftops and theirbenefits. The demonstration project has thepotential to affect the municipality'ssustainable development plan, communityenergy plan, water and stormwatermanagement plans as well as its long-terminfrastructure plan. Monitoring equipmentwill be installed to quantify the benefits.

Waterloo won the CanadianAdministration Municipal Award (CAMA)for its Environmental Strategic Plan, whichtook over a year to complete. The Mayor’sEnvironmental Task Force is identified asthe local champion for the green rooffeasibility study and demonstration site. Inaddition, Karen Moyer, Waterloo’sEnvironmental Coordinator, was awarded theGreen Roof Civic Award of Excellence at the2005 Green Roofs for Healthy Cities’Conference in Washington D.C. This awardrecognizes a public servant for outstandingcontribution to the community and thedevelopment of the green roof industry.

July 12, 2005, was the inaugural meeting ofa regional steering committee fordevelopment of a green roof policy. At thismeeting representatives from the City of

Waterloo, the Region of Waterloo and thecities of Kitchener and Cambridge discussedthe purpose and benefits of creating asteering committee and how best to moveforward on creating green roof policy. Thecommittee is considering incentives, suchas density bonuses and reducing stormwatercharges, marketing and educationalinitiatives, developing specifications forcommon requirements to ensure theinstallation of proven green roof systems).

EffectivenessWaterloo’s work so far has been inplanning, but it appears that through theCity’s involvement of all departments in thedemonstration project and theEnvironment First philosophy that thedemonstration project will be successfuland result in opportunities to retrofit otherCity-owned buildings. Though localdevelopers are not yet fully engaged, Ms.Moyer feels that this will come as awarenessof the demonstration project increases.

The proposed stormwater utility is expectedto play a major role in furthering the devel-opment of green roofs on new and retrofitbuildings because is it one way a businesscan reduce its stormwater fees.

Lessons learnedOne of the initial barriers the City hasovercome is defining a green roof. It isexpected that the accessible demonstrationgarden and results of monitoring willovercome doubts about the capability ofgreen roofs of mitigating stormwater runoffand improving air quality.



41

Ms. Moyer notes the importance of involving all city departments, council and the com-munity in planning process. She credits theEnvironment First philosophy and the Imagine! Waterloo visioning exercise as critical steps.

Local, national and international recognition for the City’s efforts has also proven to be essential for obtaining community and councilsupport.

PredictionsWaterloo’s past planning, visioning activities and reports have set the stage for moving to the point where new development willautomatically consider a green roof as part of an integrated green building design and existing buildings will investigate the possibility of agreen roof when re-roofing.

Ms. Moyer expects that once the public fully supports green roofs it will ask council to create policy to ensure that green roofs becomethe standard, not the exception, in Waterloo.

Karen MoyerEnvironmental Co-ordinatorCity of Waterloo(519) [email protected]

Key literatureCity of Waterloo website (n.d .). Retrieved from http://www.city.waterloo.on.ca/DesktopDefault.aspxCity of Waterloo. (2004). Green Roof Feasibility Study and City Wide Implementation Plan. City of Waterloo. (2002). Environmental Strategic Plan.



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Contact information


United States of America

DescriptionIn 2002 Chicago Mayor Richard Daley proclaimed that Chicago would become“America's greenest city” and should live up to its motto, Urbs in horto (City in agarden).

Despite some challenges with high summer temperature and damp, cold winters,green roofs are being built and declared an acceptable means to support highersolar reflectivity (that is, applications that lower the absorption of solar energy),mitigate urban heat island effects and improve Chicago's air quality.

The Chicago Department of Planning and Development has been activelyencouraging the installation of green roofs on Chicago's buildings since early 2003.Currently, the City of Chicago has developed a Building Green/Green Roof policythat applies to construction projects that receive public assistance or are subject toreview by the Department of Planning and Development as a PlannedDevelopment or a Lakefront Protection Ordinance Development. These measuresplace Chicago at phase 6 in policy development. Chicago is now in a position toexamine continuous quality improvements in its green roof programs.

Chicago is located at the southwestern tip of Lake Michigan. The city has apopulation of 2.87 million and occupies a total area of 606.1 km2 (234.0 sq. mi.)of which about three per cent is branches of the Chicago River. Weather can beextreme in summer, with high heat and humidity (Chicago has had many heat-related deaths) while in winter it can be damp and cold. The city's location on


Case studies

Chicago

Key motivators Urban heat island and air quality

Policy phase 6 - Continuous improvement


Longitude 87°54' W Latitude 41° 59' N


27°C (80°F)


-6°C (21°F)


72 cm (28 in.)


24 cm (9 in.)

Map of Chicago


Green Roof pol ic ies worldwide—Chicago

Lake Michigan, coupled with the flat,Midwestern terrain, combine to makesometimes unpredictable and occasionallyextreme weather.

The largest portion of Chicago's urbanfabric is vegetative land cover (ground andcanopy cover) at almost 40 per cent,followed by paved surfaces (31 per cent)and total roofed area (27 per cent).Chicago boasts having five of the 10 tallestbuildings in the United States. From 1991to 1998, Chicago planted more than500,000 trees for a new over 4.1 milliontrees. Chicago's Bureau of Forestry plantsa minimum of 5,000 new trees per year.

In paved surfaces, transportation has thehighest percentage (69 per cent).Commercial suburban has 61 per cent;commercial urban, 51 per cent andindustrial, 48 per cent.

Key motivatorsThe City of Chicago is concerned aboutthe effect of urban heat islands and poorair quality on human health and quality oflife. Ordinances such as the EnergyConservation Code, passed in 2001, havehelped to promote green roofs by

requiring that all new and retrofit roofsshould meet a minimum standard for solarreflectance (.25 reflectance is coderequirement). The city shaped theordinance in response to a severe heatwave that hit the area in 1996, whichcontributed to a significant number ofdeaths, particularly among senior citizens.The city's Bureau of the Environmentdeemed that green roofs were anacceptable means to lower roof reflectivity,mitigate urban heat island and improveChicago's air quality.

In 2003 at the inaugural Green Roofs forSustaining Healthy Cities Conference in

Chicago, Mayor Daley received the 2003Civic Award of Excellence for hisleadership in promoting green roofs. ThePeggy Notebaert Nature Museum, at theChicago Academy of Sciences, received the2003 Green Roof Award of Excellence.The Museum, on the shore of LakeMichigan, is a green roof demonstrationproject that educates visitors about greenroofs as they tour the museum.

Description of policyThe Chicago Department of Planning andDevelopment has been activelyencouraging the installation of green roofson Chicago's buildings since early 2003.The matrix summarizes the City'sBuilding Green/Green Roof policy,showing what projects are subject to thepolicy and what green strategies arepromoted through the policy.

Basically, the City of Chicago grants adensity bonus option to developers in theform of a floor area premium. To qualifyfor more intense development or morefloors in a new building project, at least 50per cent of the roof surface area or aminimum of 185.8 m2 (2,000 sq. ft.) -whichever is greater - must be covered byvegetation - typically in the form of agreen roof.

Process to establish thepolicyInterest in green roofs in Chicago beganwhen Mayor Daley visited Europe in 1998and noticed the large number of greenroofs. In 2003, the city Department ofEnvironment designed and installed a1,886 m2 (20,300 sq. ft.) demonstrationproject on the roof of City Hall. Othercity-sponsored green roof projects thatyear were the Chicago Center for Green

Technology and the Chicago TransitAuthority Substation as well as a few cityfire stations.

In 2003, to encourage the private sector toplay a leadership role in establishing greenroofs, the Department of Planning andDevelopment engaged the Chicago UrbanLand Institute (ULI) a non-profitorganization of real estate professionals, tohold seminars on green roofs to dispelfears and misconceptions about greenroofs. Similarly, professionals weresurveyed to determine what incentiveswould be most attractive for them toinstall green roofs. Table 2 shows theresults.

EffectivenessAccording the Michael Berkshire, GreenProjects Administrator with Chicago'sDepartment of Planning andDevelopment, there is more that 92,903m2 (one million sq. ft.) of green roofs inChicago. (See figure 2) The City ofChicago has a website that supports greenroof installation, information andtechnical assistance. Documents availableon the website include:

� A guide to rooftop gardening

� Design guidelines for green roofs

� Extensive green roofs - what are thebenefits of green roofs?

� Green roof basics (structural buildingrelated information)

� Green building projects includingthose with green roofs

� A guide to stormwater bestmanagement practices (green roofs arenoted under best managementpractices (BMPs).


45Canada Mortgage and Housing Corporation

Lessons learnedWhile Chicago offers a stormwaterretention credit for green roofs because oftheir ability to reduce and delay stormwaterrunoff, there is no stormwater impact fee.Similarly, parts of Chicago, such as theCentral Plan Area, do not require on-gradedetention of stormwater, but instead,require that stormwater be released at adesired rate to the underground stormwatersystem. While the Department of Planningand Development has created the BuildingGreen/Green Roof Matrix to guide citydevelopment, there is no requirement touse green roofs or green building strategiesin the private sector.

PredictionsThe number of green roofs in Chicago isgrowing each year, as there is strongsupport for green infrastructure in city'stop administration. Despite the lack offormal regulation supporting green roofinstallations on new and retrofit roofs inChicago and the upfront costs that areperceived to prohibit their use bydevelopers, green roofs are predicted togrow in the Chicago marketplace.According to Lois Vitt Sale, a design andconstruction consultant with theDepartment of Planning and Development,local green roof performance data,competitive pricing for green roofinfrastructure and higher energy costs willspur the Chicago green roof market in yearsto come.

Public assistanceRFPs, Negotiated Saleswith land writedown,TIF,Empowerment ZoneGrants, DOH

Public assistanceBond Issues, Class 6b,SBIF, Enterprise ZoneFacility Bonds, BankParticipation Loans

No public assistancePlanned Developments,Lakefront ProtectionOrdinance Developments

Residential

Market Rate SF and THMulti-units<4 units

Energy Star or LEEDcertification

Market Rate=>4 units 50% Green Roof andEnergy Star Certificationor LEED Certification*

50% GreenRoof and Energy StarCertification*

25% Green Roof*

>20% Affordable Units orCPAN

DOH Green Criteria

Institutional

Hospitals 50% Green Roof or 25%Green Roof and LEEDCertification*

>25% Green Roof or10% Green Roof andLEED Certification*

25% Green Roof or 10%Green Roof and LEEDCertification*

Community centres andschools†


Industrial

10% Green Roof orEnergy Star Roof andLEED Certification

>10% Green Roof andEnergy Star Roof

Commercial

Retail>10,000 sq. ft.‡ 75% Green Roof or 50%Green Roof and LEEDCertification*


50% Green Roof*

Retail<10,000 sq. ft. 25% Green Roof orLEED Certification*

Energy Star Roof Energy Star Roof

Office>80 ft. 100% Green Roof 75% Green Roof* 50% Green Roof*

Office<80 ft. 50% Green Roof orEnergy Star Roof andLEED Certification

Energy Star Roof

Legend

SF=Single familyTH=TownhouseRFP=Request for ProposalsTIF=Tax Increment Financing

SBIF=Small Business Improvement FundDOH=Department of HousingCPAN=Chicago Partnership for AffordableNeighborhoods

* Remainder of roof must meet Energy Star levels for reflectivity.† Church buildings serving multiple purposes will be considered a community center.‡ Run-off coefficient value reduction will be required for big-box retail projects more than 100,000 sq. ft.

NOTE:All projects reviewed by the Department of Planning and Development are encouraged to usestormwater best management practices, LEED and Energy Star building standards and residential greenbuilding standards where applicable.A 50% green roof and LEED certification are required for all public projects except community centersand schools.

LEED certification plus a 10 per cent green roof or a 25 per cent green roof will be required for PublicCommunity Centers and School Community Centers. Schools will also focus on indoor air quality and daylighting.

LinksGreen Roof Information - www.greenroofs.comEnergy Star Roof - www.energystar.gov/index.cfm?c=roof_prods.pr_roof_products Energy Star Certification - /www.energystar.gov/index.cfm?c=home.index LEED Certification - www.usgbc.org/DisplayPage.aspx?CategoryID=19

Table 6 - Chicago's Building Gree-green roof matrix



Table 6 - Map Showing Green Roof Projets in Chicago


47

Key literatureCity of Chicago. (n.d.). Building Green/Green Roof Matrix. Retrieved fromhttp://egov.cityofchicago.org/webportal/COCWebPortal/COC_EDITORIAL/Green_Roof_Policy_Matrix_revised.pdf

City of Chicago. (2004). The Chicago Standard. Retrieved fromhttp://egov.cityofchicago.org/webportal/COCWebPortal/COC_ATTACH/ChicagoStandard.pdf

Sale, L., & Berkshire, M. (2004, June). Creating a Marketplace for Green Roofs in Chi-cago. Presented at the Greening Rooftopsfor Sustainable Communities, Portland .



09-05-06

Contact information

ContactsMike BerkshireGreen Projects AdministratorDepartment of Planning andDevelopmentCity of Chicago(312) [email protected] Lois Vitt SaleCorporate Vice PresidentWight and Company(312) [email protected]

Table 7 - Most attractive incentives for green roof installation

The Department of Planning and Development partnered with green roof providers tobuild and compare green roof test plots using different kinds of plants and materials.TheMayor's Water Agenda in 2003 recognized the benefits of improved stormwater man-agement with a proclamation that “green infrastructure and design would be encouragedin City projects” including the use of green roofs.The Department of WaterManagement (DWM) re-calculated detention requirements to include green roofs asequal to vegetated areas at grade level.The DWM uses a “C” factor to calculate runoffvalues and deter-mined that green roofs were equal to grass. Nonetheless, not alljurisdictions in Chicago rate green roofs equally. For example, the Metropolitan WaterReclamation District does not recognize the benefits associated with a six-inch greenroof system for runoff control.

DescriptionNew York’s population of about 8.1 million lives on a land area of about 834 km2

(322 sq. mi.). Located at the mouth of the Hudson River on the eastern Atlanticcoast of the U. S., New York has a temperate maritime climate.

New York faces challenges related to the quality of its natural waterways fromstormwater and sewage and challenges related to urban heat island effect.

These challenges present opportunities for consideration of green roofs. New Yorkis behind Portland, Chicago and Washington D.C. in developing green roofpolicies. It appears that similar to Toronto, New York intends to develop policiesafter completing more detailed studies of the benefits of green roofs.

Earth Pledge, a non-profit organization, is bringing the various stakeholderstogether to document the costs and benefits of green roofs.

Intensive activity that falls within policy phases 3 and 4 is taking place in NewYork. The activity showcases Earth Pledge’s unique approach.


Case studies

New York, New York

Key motivators Urban heat island, stormwater runoff

Policy phase 4 — Technical Research

Champion Non-profit sector

Longitude 41°N Latitude 74°W


25°C(77°F)


0°C (32°F)


1,200 mm(47 in.)


700 mm (27 in.)*

*Snowfall in New York contributes very little to precipitation

Map showing New York City, New YorkScale 1:4,000,000


Green Roof pol ic ies worldwide—New York

49

Key motivatorsNew York has several environmentalchallenges. Urban heat island has existedsince the early 20th century and it is believedto increase city temperatures by two to threedegrees Celsius compared to the surroundingareas. Pollution from stormwater runoff is aconcern because it compromises the healthof New York's water. Every year, half therainstorms in New York overflow thecombined sewage system, pouring anestimated 40 billion gallons of untreatedwastewater into city waterways.

Description of the policyThe Earth Pledge Foundation is a non-profitorganization that identifies and promotesinnovative techniques and technologies thatrestore the balance between human andnatural systems. In New York, the promotionof green roofs has been primarily throughthe efforts of Earth Pledge, which hasundertaken several green roof initiatives.Earth Pledge hopes the initiatives will leadto private and municipal governmentsupport for green roofs in New York.

Process to establish policyTo support government evaluation of locallyappropriate green roof infrastructure andpolicy support structures, Earth Pledge has:

� done research to quantify the costs andbenefits of green roofs for New York;

� educated the stakeholders whoseparticipation is crucial to achievingwidespread green roof development inNew York; and

� implemented green roof projects.

This information is not yet publiclyavailable but is expected to be availablesoon through the Earth Pledge website.

The Earth Pledge projects are the NewYork Green Roof Policy Task Force, GreenRoof Symposia and Workshops, GreenRoof Toolbox, Green Roof InfrastructureStudy, Green Roof Stormwater Model(GRSM), the New York EcologicalInfrastructure Study (NYEIS), GreeningGotham.org, the Viridian Project and therecently published book Green Roofs:Ecological Design and Construction:

New York Green RoofPolicy Task ForceThis is a group of public officials andrepresentatives from government agenciesconvened by Earth Pledge to explore policyoptions in support of green roof development.Agencies represented include New York’sDepartment of Environmental Protection,Mayor’s Office of EnvironmentalCoordination, the Department of HousingPreservation and Development; HousingAuthority; the Battery Park City Authority,Department of City Planning; Departmentof Parks; U.S. Environmental ProtectionAgency, Region 2; and the United StatesForest Service.

Members of the task force engage with theirparent agencies to help determine needsfor evaluating how each agency can bestengage in green roof development, throughpilot projects, specifications development,incentive creation or policy support.

Green roof symposiaand workshopsEarth Pledge holds green roof events thatengage and educate a range of stakeholdergroups, including technical workshops andgreen roof symposia for design and buildingprofessionals that bring together a diversegroup of designers, builders, developers,educators and community and environmental

groups. Well over 1,000 professionals haveparticipated.

Green Roof Toolbox The Green Roof Toolbox is an onlineresource for design and buildingprofessionals, policymakers and the public.It provides detailed information tofacilitate green roof project development.

Green roofinfrastructure studyUnder contract with the New York StateEnergy Research and DevelopmentAuthority and the Clean Air CommunitiesFund, Earth Pledge’s research team ismonitoring in-situ two green roofs inLong Island City, Queens.

Green roof stormwatermodel Under contract from the New York WaterBoard, Earth Pledge is building a theoreticalstormwater-modeling tool to evaluategreen roof runoff reduction at the buildingand drainage basin scale in Lower Manhattan.

The New YorkEcological Infrastructure(NYEI) Study This project investigates the form andfunction of an “ecological infrastructure”for New York’s built environment andlandscape. The study emerged from adesire to develop a cost-benefit analysis ofcity-wide green roof implementation.

Development of a New York “ecologicalinfrastructure” can restore lost ecosystemfunction, address current environmental,health and economic concerns andestablish a vision for a sustainable urban



future. The study is intended to providepolicy-makers with a set of scientific analysesand balanced benefits and costs to determinethe rationale for and the proper means ofsupporting green roofs and other measures.

Greening Gotham.orgThis web-based project presents EarthPledge’s vision for improving the urbanenvironment by bringing to life a barrenand abandoned landscape — New York'srooftops. Greening Gotham.org enablesNew Yorkers to share in that vision, learnabout the urgent environmental problemsthat face the city and how green roofs cansolve them. A regularly updated newssection lets New Yorkers track the progressof green roof work in the city — new greenroof projects, public events and publicpolicy developments. It is supported byNew York Mayor Michael Bloomberg,Senator Hillary Clinton (D-N.Y.), actor EdNorton and many others.

The Viridian ProjectThe Viridian Project brings the environmental,health and social benefits of green roofs tolow- and moderate-income communities.Through Viridian, Earth Pledge is providingtechnical and financial support to non-profit organizations that serve these groups,in order to help them develop green roofsand related programming at affordablehousing and other community facilities.

Green roofs: Ecologicaldesign and constructionPublished by Schiffer Design, Earth Pledge'smost recent publication includes hundredsof photographs, 40 case studies of exemplarygreen roof projects, seven municipal casestudies and design details.

Effectiveness The approach in New York has been effectiveon various fronts. The Green Roofs TaskForce has detailed the type of informationgovernment agencies need and highlightedareas for further studies.

The U.S. EPA Region 2 supported the taskforce by funding the GreeningGotham.org. website.

The NYEI study undertook a comprehensiveanalysis, from 2002 to 2004, of the impacts,costs and benefits of citywide green roofing.

Earth Pledge has an ongoing relationshipwith the New York Department ofEnvironmental Protection (DEP), whichhas funded the development of two computermodels of green roof performance for LowerManhattan. The models will provide the firstsignificant green roof stormwater analysisusing New York climate and sewage data.

In Queens, the Pratt Institute Centre forCommunity and Environmental Developmentis developing a green roof on a metalfabrication plant as part of a plannedneighbourhood-wide test site for greentechnologies and green industries. The roofwill be monitored for energy use and willbe financed in part by the New York StateEnergy Research and Development Authority.

The Earth Pledge Viridian Project haspartnered with a number of communitygroups and housing organizations, whohave installed green roofs as a way to addgreenery in limited space. Six projects havebeen completed. Viridian also has severalpartnerships with schools.

Green roofs offer a unique solution for theSouth Bronx sewer shed, whose land area isdensely built, with 75 per cent covered byroof space. Funding has been granted to

form the Bronx River Alliance, which willconsider incorporating green roofs into theborough's environmental strategies. Inaddition, a Bronx Initiative for Energy and\funded by a one-time appropriation of $1 million. BIEE funds energy-efficientprojects — including green buildings —with solar panels and green roofs.

In Lower Manhattan, the Battery Park CityAuthority (BPCA) has taken steps towardsthe creation of green infrastructure. The BPCAhas mandated stringent environmentalrequirements for all new buildings. The 27-storey Solaire residential high-rise in thefirst built to these specifications and itincludes two green roofs — one accessibleand another inaccessible.

A number of private companies have alsobuilt green roofs in New York, includingthe Nassau Brewery Icehouse in Brooklynwith one inaccessible green roof andHelena, a luxury high-rise with fiveextensive green roofs.

Municipally funded green roofs are plannedfor the St. George Ferry Terminal on StatenIsland and at the Queens Botanical Gardens.New York City Council is also examininggreen building policies, including legislationthat would require all publicly funded buildingsto be LEED Silver certified. The BuildingDepartment is also seeking to incorporatebuilding technologies — including green roofs— into the International Building Code,which is the building code used by New York.

Lessons learnedEarth Pledge endeavoured to frame city-widegreen roof development and subsequentlypolicy support, in terms of its potential tomeet a wide spectrum of needs. It hassucceeded in laying the groundwork forthis type of approach.



51

By allowing government representatives to articulate the challenges facing the city — whether relating to stormwater pollution, affordablehousing or open space equity — green roof development in New York has taken on its proper quality: one of many potential solutions tocomplex problems arising from numerous interrelated factors. It has become more likely that future green roof development willinterdisciplinary to maximize benefit to the city.

Through Earth Pledge’s experience it seems that the evaluation of green roof potential in New York cannot be solely the purview ofgovernment. No matter the mandate, government is not able to represent all the interests of a community, its culture or its environment.In serving as the convening and coordinating entity, Earth Pledge has been able to draw upon the range of its other activities to illuminateand inform the political process to make certain that other scientific, environmental, social and economic needs are brought to the tableand integrated into the agenda.

For other cities considering city-wide green roof development, New York can provide a model for framing the political process to effectivelyrespond to local needs by incorporating green roofs. As presented throughout this Manual, cities in Europe, Asia and other parts of NorthAmerica provide important examples of how green roofs were developed and the types of support structures implemented to encouragetheir construction. The approach in New York, however, can demonstrate how green roofs are a fascinating ecological building techniquefull of potential to positively affect a range of challenges facing the urban landscape.

PredictionsGreen roof support in New York is expected to grow and be encouraged by private sector efforts through the development of policies andprograms by governmental organizations.

Leslie HoffmanEarth Pledge(212) [email protected]

Key literatureCheney, C. (2004, June). The New York Green Roof Policy Task Force: A Model for Context-Appropriate Urban Green RoofDevelopment. Presented at the Greening Rooftops for Sustainable Communities Conference, Portland.

Cheney, C. (2005). Greening Gorham’s Rooftops. In Earth Pledge, Green Roofs: Ecological Design and Construction (pp. 130-134). New York, New York: Schiffer Publishing Ltd.



09-05-06

Contact information

DescriptionPortland is considered the North American leader in green roofs. Oregon’s largestcity, with a population of about 2 million, covers 13,022 km2 (5,027 sq. mi.). It is located ap-proximately 112 km (70 mi.) inland from the Pacific Coast on theWillamette River and is bordered by the Coastal and Cascade Mountain ranges.The city has a temperate climate with mild spring and summer weather. It receivesheavy rains in the late fall and winter with a three month dry season (drought) inthe summer. Its climate is similar to that of Vancouver.

There is very little specific data available about inventory of land use inventory.However, Portland is known for its smart growth policies. Current developmentaround Portland is held within the Urban Growth Boundary.

The main motivator for green roofs is stormwater management, in particular thereduction in combined sewage overflow.

Portland moved very quickly through the first three phases of policy development.It has conducted significant technical research and phase 5 is well underway.Portland shows that where there is political will, things happen.

Unlike New York, which is studying the costs and benefits of green roofs beforemoving forward, Portland was able to quickly fund many demonstration andexperimental projects based on their success in Germany. Today, new municipalbuildings are required to consider green roof installation. Portland's municipal


Case studies

Portland, Oregon

Key motivators Pollution from stormwater runoff


Champion Municipal

Longitude 46°N Latitude 123°W


20°C (68°F)Average wintertemperature

4°C (39°F)


900 mm(35 in.)


50 mm(1.9 in.)*

*Snowfall in Portland contributes insignificantly to total precipitation

Map showing City of Portland, OregonScale 1:4,000,000


Green Roof pol ic ies worldwide—Port land

53

website promotes green roofs and provideshelpful advice to those in the private sectorconsidering green roofs.

Portland quickly included green rooftechnology as an acceptable option in itsexisting development bonus schemes, suchas floor area ratio (FAR) bonus and as anacceptable measure to reduce stormwatermanagement charges.

As of the summer of 2005, the City waslooking at details of the municipal level costsand benefits to further evolve policies. Thesuccess in Portland is attributed by many toone municipal employee: Tom Liptan, althoughnon-profit organizations such as EcoroofsEverywhere now promote green roofs.

With the success at the civic level, Portland isnow reaching out to fully engage thecommunity to ensure the success of green roofs.

Key motivatorsWhile many benefits are attributed to greenroofs, or ecoroofs as they are called inPortland, the main motivator has been theissue of combined sewer overflow. This issuebecame critical when a 1994 state mandaterequired that Portland comply with theClean Water Act and clean up the WillametteRiver — a significant stretch of which isnow a designated Superfund site — theEnvironmental Protection Agency (EPA)program to clean up hazardous waste sites.

Portland is currently building a pipeline onthe west side of the Willamette River and alarge pump station to deal with combinedsewer overflow. It is also designing an east-sidepipeline to reduce combined sewer overflowvolume to the river by 94 per cent. The pricetag for compliance, based on these structuralchanges to reduce combined sewer overflow,is estimated at $1 billion.

This strategy, however, will need to besupplemented with additional inflow andman-agement strategies after 2011, whenit is anticipated that the new infrastructurewill reach full capacity.

The City of Portland Bureau ofEnvironmental Services (BES) began toinvestigate alter-natives to structural changessuch as decentralized stormwater managementtechniques, including green roofs/ecoroofs.

Description of policyThe City promotes ecoroofs but does notrequire them, except for its own facilities.

Ecoroof requirements for publicbuildings

All new, city-owned facilities are requiredto be designed and constructed with anecoroof that covers at least 70 per cent ofthe roof. The remaining roof area must becovered with Energy Star-rated roofingmaterial. All roof replacements are requiredto include an ecoroof when practical.

Ecoroof requirements for privatebuildings

There are no requirements for ecoroofs forprivate developments. The City has stringentstormwater management requirements,outlined in its Stormwater ManagementManual, which directs all developmentand by which the City retains its federalstormwater permit.

In areas of the city, such as the CentralCity District, developments must complywith design guidelines that are intended toprotect the architectural and cultural integrityof the area. Each project in these areas goesthrough design review. Ecoroofs, also called“rooftop stormwater facility” in the guidelines,are considered for their contribution towards

improving the esthetics around the site inaddition to managing stormwater onsite.

Since 2001, the city’s zoning code has alsooffered developers zoning bonuses whenthey implement stipulated options, such asecoroofs. The floor area bonus iscalculated at three thresholds:

1. A 10–30 per cent ecoroof coverageresults in floor area ratio bonus of 1:1;

2. A 30–60 per cent ecoroof coverageresults in a bonus of 2:1;

3. A coverage greater than 60 per centecoroof results in a bonus of 3:1.

The owner must sign an agreement thatensures roof proper maintenance in compliancewith the zoning code. The details and periodof such agreements were not clear in thesummer of 2005. However, the city perceivesmaintenance to be a problem.

Another financial incentive being consideredis the reduction in charges for stormwaterretention by soft landscaping as opposedto impervious area on the site. Buildingswith ecoroofs would qualify for such areduction. This anticipated stormwater feewill offer a 35 per cent reduction in stormwaterrates for owners who install ecoroofs withat least 70 per cent of the roof area coveredwith an ecoroof. Now, the stormwatermanagement charge for commercial, industrialand institutional ratepayers is $6.06 US per1,000 sq. ft. (93 m2) of impervious area amonth. The current stormwater managementcharge for single-family residences is$13.30 US a month. The charge appears onthe city’s water/sewer utility bill and is pro-rated at a rate of $0.43721 US a day.

Policy application

On public projects, all municipal projectmanagers are required to consult the city’s

54Canada Mortgage



inter-bureau Green Building Advisory Team(GBAT). The GBAT provides upfrontassistance and guidance by outlining strategiesto meet the Green Building Policy objectives(LEED Gold and Ecoroof). GBAT is, in effect,the City’s internal green building consultants.

On private projects there are no additionalrequirements since the mechanisms to promoteecoroofs all fall with the city’s existingframework. For example, the city offersfloor area ratio (FAR) bonuses for a variety ofdevelopment practices that meet the City’sobjectives, such as providing public art,housing and child care facilities. There are othertechnical strategies to comply with the Storm-water Manual and Design Guidelines similarto low impact development (LID) techniques.

Public outreach andeducationThe City of Portland’s Ecoroof Program haseducational and outreach components.Through this program, the city providestechnical assistance to building ownersconsidering applying an ecoroof, providesgrants for ecoroof demonstration projects,conducts ecoroof tours and monitors ecoroofs.

Process to establish policyPortland is the first city in the U.S. to passlegislation promoting green roofs, the resultof the requirement to conform with the CleanWater Act. One response was to developstrategies that would increase surface waterabsorption and reduce imperviousnessaround developments.

Portland began to research ecoroofs as astormwater management tool in the mid1990s. Encouraged by the results of theresearch, which showed that an ecoroof wasable to retain rainfall, the city funded anecoroof demonstration exhibit at the PortlandHome and Garden Show. City officials surveyed

public opinion at the show and found that75 per cent of the responses were favourable.Based on these results, the City funded,from stormwater fees, two green roof testsites: the 10-storey Hamilton Apartmentsand five-storey Buckman Terrace.

The successful outcomes from the two testsites encouraged the city to promoteecoroofs as a stormwater management tool.

The city has used a variety of policy structuresto support green roof construction. The cityprovides technical assistance to developers andarchitects. In addition, the City set up anecoroof demonstration grant program.Technical data from grant projects isdocumented and publicly available.

Most public ecoroof projects have beenfinanced by stormwater fees. Portland has asplit fee system, with separate charges for waterconsumption, sanitary discharge and treatmentand stormwater management. In 2001, thecity split the stormwater fee in two– 35 percent based on drainage on the property and65 per cent of the fee based on drainage ontopublic streets, calculated according to the amountof impermeable surface area on the property.

Ecoroofs have been formally recognized as abest management practice in the city'sstormwater manual since 1999. The city isconsidering a discount on the stormwaterrunoff fee for properties using certain bestmanagement practices. Installing a greenroof will earn one of the highest discounts.

Since the early 1980s, Portland hasrecognized green roofs as an asset to theurban environment and created a FARzoning code bonus that included greenroofs. This applies to the dense downtowndistrict, a priority stormwater managementarea, where zoning limits height-to-floor-area ratio. This original roof garden bonuswas not widely used. In 2001, the city

added extensive ecoroofs, which useshallower growing media, to the program.

In recent years, a citizen group calledEcoroofs Everywhere has taken the lead inencouraging equitable distribution of greenroofs across all income levels. The groupcreates af-fordable demonstration projects,secures grants for small-scale developmentsand negotiates lower prices with vendors.

Portland gained international recognitionfor its green roof efforts by co-sponsoringthe Greening Rooftops for SustainableCommunities Conference in 2004.

Effectiveness By January, 2004, over 30 new green roofswere built or being in Portland, includingfive on government buildings. It isestimated that there are two acres ofecoroofs in Portland with another two acrescommitted to be built.

By the end of 2004, four developments hadbenefited from the FAR bonus toimplement green roofs.

Portland has raised awareness of thebenefits of ecoroofs so effectively that theprivate sector has begun to construct them

on its own initiative. Many people areinstalling ecoroofs on their houses.

Lessons learnedPortland's support for green roofs is aphased approach, similar to the Germanmodel, which has used research to buttresspublic investment in green roof projectsand policies. The city has used subsidiesand incentives to encourage privateinvestments in green roofs. Publiceducation and civic consciousness has alsobeen integral to the success of green roofs.



55

The incentives and subsidies do not seem to have encouraged ecoroofs on industrial buildings, which generally have larger impermeablesurface areas.

PredictionsThe successful continuation of green roof construction in Portland will likely depend on the success of current programs and policies.Evaluation of Central City Design Guidelines policies is expected. Some parts of the evaluation were presented at the 2005 GreeningRooftops for Sustainable Communities Conference, which the City of Portland and Green Roofs for Healthy Cities co-sponsored. Thisanalysis will become increasingly relevant in determining the effectiveness of ecoroofs in decentralized stormwater management.

It is also expected that a geographical information system (GIS) will be used to identify priority areas for ecoroofs. For these priority areas,it is expected that the city may consider an upfront incentive to partially offset the capital cost of a green roof.

Key literatureJohnson, M. (2004, June). The Role of Land Use Tools in Portland's Toolbox for Pro-moting Eco-Roofs. Presented at the GreeningRooftops for Sustainable Communities, Portland.

Liptan, T. (2003, May). Planning, Zoning and Financial Incentives for Ecoroofs in Portland. Presented at the Greening Rooftopsfor Sustainable Communities, Chicago.

Liptan, T. (2005). Portland: A New Kind of Stormwater Management. In Earth Pledge, Green Roofs Ecological Design and

Construction (pp. 130-134). New York, New York: Schiffer Publishing Ltd.



09-05-06

Marie JohnsonSenior PlannerBureau of PlanningCity of Portland(503) 823 [email protected]

Tom LiptanBureau of Environmental ServicesCity of Portland(503) 823 [email protected]

Terry MillerOffice of Sustainable DevelopmentCity of Portland(503) [email protected]

Contact information


International

DescriptionLocated in northwestern Switzerland on the Rhine River and bordering Germanyand France, Basel has a population of about 187,000. It is in the most successfuleconomic region of Switzerland, with the pharmaceutical and chemical industriesforming the backbone of its economy. Many major Swiss banks have central officesin Basel, giving finance a pivotal role in the local economy. Basel-City is one of 26cantons (states) of Switzerland with its own constitution, legislature, governmentand courts.

Basel has a mild climate due to its location in the Rhine valley at an elevation of277 m (909 ft). It receives Mediterranean air currents and lots of sunshinethroughout the year. Winters are characterized by short, cold periods, with longermoderate ones (rain and temperatures between 0 and 5°C [32 and 41°F]). Baseltypically has a light snow cover for about 25–30 days, which does not stay on theground for more than two weeks at a time.

The city is interested in green roofs for energy saving and biodiversity protection.The municipality first explored green roofs as an energy-saving measure forbuildings. An electricity tax generated funds. The municipality was quick toinvolve a variety of stakeholders, such as business associations and environmentalorganizations, in developing an incentive program.

Green roofs were funded for a two-year period in the mid-1990s to stimulateinterest and awareness. Encouraged by the success of this project, funds wereallocated for a study documenting the biodiversity benefits of green roofs. Theincentive program, in combination with the outcomes of the research, led to


Case studies

Basel-City, Switzerland

Key motivators Energy savings and biodiversity

Policy phase 6 — Continuous Improvement


Longitude 47°33' N Latitude 7°35' E


24°C(75°F)


-2°C (28°F)


784 mm(31 in.)

Map showing City of Basel, SwitzerlandScale 1:4,000,000


Green Roof pol ic ies worldwide—Basel-City

including green roofs in buildingregulations. Another incentive program isplanned for 2005–2006. Basel has reachedpolicy phase 6 as it is exploring means toimprove its second incentive program byincorporating quality control measuresinto the guidelines.

The biodiversity research conducted inBasel has produced convincing evidencethat a green roof ’s can protect endangeredinvertebrate species. London, England isexploring a similar approach to green roofdevelopment as a result of this research.

Table 8 — Land use, Basel-City

Key motivatorsReducing energy consumption ofbuildings and protection of biodiversityare the key motivators for green roofs inBasel. Research by Dr. Stephan Brenneisenchampioned green roofs. The researchdocuments and details how green roofs canprotect endangered invertebrate species.

Description of thepolicyIn 1996 and 1997 Basel invested 1 millionCHF (Swiss francs) ($670,000 Cdn ) in agreen roof incentive program. Funding forthe program came from electricity fees, aportion of which must be used for energy-saving measures. Another 1 million CHFgreen roof incentive program is planned for2005–2006. The Department of Environmentand Energy administers the program.

With the success of the first incentiveprogram, in 2002 green roofs wereincluded in building regulations. Theregulation states that all new andrenovated flat roofs must be greened toprovide valuable habitat.

The green roof regulation says:

� The growing medium should be nativeregional soils — the regulationrecommends consulting ahorticulturalist.

� The growing medium should be atleast 10 cm (4 in.) deep.

� Mounds 30 cm (11 1⁄2 in.) high and 3m (10 ft.) diameter should be built atrandom to foster insect life.

� Vegetation should be “Basel mix” — a mix of native plant species.

� Builders of green roofs on flat roofs1,000 m2 (10,764 sq. ft.) or more mustconsult Dr. Brenneisen during designand construction.

Basel has reached policy phase 6. It hasimplemented incentive and regulatorytools to promote green roofs in itsjurisdiction and is now exploring ways toenforce compliance with designspecifications.

Process to establishpolicyThe Department of Environment andEnergy conducted a poll to determine thelevel of support for an electricity tax to payfor energy-saving measures. The resultsfavoured a tax and the city exploredenergy-saving ideas, including green roofs.The city consulted various stakeholderswhen considering green roofs and inestablishing the first incentive program.Stakeholders included the local businessassociation, the horticultural association,the green roof association, the Pro NaturaBasel environmental organization, thedepartment of parks and cemeteries andthe National Department of Environment,Forest and Landscapes.

The Department of Environment andEnergy decided to pursue and promotegreen roofs and launched the firstincentive program.

The incentive program spurred interest inresearch on the biodiversity protectionbenefits of green roofs. Dr. StephanBrenneisen received 40,000 CHF to carryout the research, which discovered thatgreen roofs have great potential as valuablehabitat for invertebrate species and birdsand could be designed to maximizebiodiversity by using native plants andsoils, varying topography, bare patches andusing wood and rocks.

This research, in combination with thesuccess of the incentive program, LED theCity to institute green roofs in buildingregulations. Dr. Brenneisen’s study was akey part in setting green roof designspecifications.

Use Percentage

Forest 17%

Agricultural 17%

Building 23%

Recreational 13%

Traffic 25%

Water 6%


Green Roof pol ic ies worldwide—Basel-City

59

EffectivenessIn 1996–97, 135 people applied for a greenroof subsidy, which led to 85,000 m2

(915,000 sq. ft.) of roofscape beinggreened. The program led to a furtherinvestment of 13 million CHF. Energysavings totalled 4 GW/year.

Media interest in the program was high,which played a large part in its success andgained nation-wide profile for Basel. To aidwith the promotion of the program, thecity held a contest for the best lookinggreen roof.

Since 2002, when the city mandated greenroofs for all new and renovated flat roofs, about15 per cent of flat roofs in Basel have beengreened.

Lessons learnedIt is important to involve all stakeholdersfrom the beginning to address questionsand concerns and ensure that everyone’sgoals are being met.

The incentive program succeeded in partbecause all stakeholders benefited. Localbusiness profited from sales of materialsand supplies, building owners realizedenergy savings and Basel gained nation-wide profile.

PredictionsEstimates are that through the green roofregulation, 30 per cent of all flat roofs inBasel will be greened within the next 10 years.

Basel is now exploring ways to enforcequality of green roofs. The incentiveprogram planned for 2005–06 will givesubsidies to applicants who show that thecity’s conditions will be met.

Applicability to CanadaBasel’s incentive program is an interestingapproach in that it concentrated efforts in atwo-year program, which significantlyraised the profile of green roofs. The largefinancial investment may be difficult forCanadian municipalities to equal. However,there may be an opportunity to partner withelectrical or water utilities to raise revenue.

The establishment of the regulation wasmet no resistance, largely because all partieswere involved in the process from thebeginning. It was also accepted because ofthe success of the incentive program.Canadian municipalities interested increating momentum and acceptance forgreen roofs could consider a Green RoofTask Force that includes a wide variety ofstakeholders.

Basel’s regulation is used to specify the typeof green roof required, in this case the purposebeing biodiversity protection. Given thatthe regulation in Basel is fairly new, therewas no mention of required green roofs notbeing properly maintained. However,ensuring design and construction quality isthe next step in the green roof development.

Dr. Stephan BrenneisenResearch Fellow and Green Roof DirectorUniversity of Wä[email protected]

Contact information

Key literatureBrenneisen, S. (2004, June). Biodiversity Strategies to Agricultural Productivity. Presented at the Greening Rooftops forSustainable Communities Conference, Portland.

Brenneisen, S. (2003, May). The Benefits of Biodiveristy from Green Roofs. Presented at the Greening Rooftops for SustainableCommunities Conference, Chicago.



09-05-06

DescriptionMünster is a low-lying, flat area with a temperate climate. The city has beenconcerned with the effects of increasing urbanization since the 1970s and, morerecently, stormwater management. Its sewer system is primarily separate for stormand waste water, with a few combined system areas on the city outskirts. Münsterhas 605 km (376 mi.) of waterways that it is working to restore and protect.

The municipality promotes green roofs through tools and incentives. In 1991,Münster applied a stormwater fee, based on the amount of impervious surface on aproperty. Installing a green roof reduces the fee by 80 to 90 per cent, based on itswater retention capacity. Residents can also apply for a state-funded incentive of 15/m2 for a green roof. The city administers the incentive.

Münster has reached policy phase 6, evident through its implementation of variousincentives and efforts to revise these to meet current environmental concerns.

Key motivatorsThe effects of increasing urbanization, such as a lack of green space, haveconcerned Münster since the late 1970s. Early incentive programs were aimed atincreasing green space and improving the quality of life in the downtown core.

In the early 1990s, stormwater management was added to the list of programgoals, to decrease the load on the sewer system and to protect the city’s extensivewaterways. The city’s fee system encourages stormwater source control measures.


Case studies

Münster, Germany

Key motivators Stormwater management

Policy phase 6 — Continuous improvement


Longitude 52°13 N' Latitude 7°70 E'


23°C(73°F)


0°C(32°F)


756 mm(30 in.)

Map showing Munster GermanyScale 1:4,000,000

Use Percentage

Building 11.4%

Traffic 6%

Agricultural 64.3%

Forest 15.1%

Recreational 1.1%

Water 1.9%

Other 0.5%

Table 9 — Land use, Munster


Green Roof pol ic ies worldwide—Munster

61

Description of thepolicyMünster has a history of financial incentiveprograms dating back to the late 1970s.The programs provided subsidies for avariety of ecological initiatives toencourage green development and offsetthe effects of increasing urbanization.These programs have since ended, with themost recent City-run incentive programfinishing in 2002.

There are two tools used to provide greenroof incentives: a state-level stormwaterman-agement program of North Rhine-Westphalia (NRW) and a stormwater fee.

The stormwater fee is 0.44/m2 per year. Ifstormwater runoff is directed into ponds,rivers, creeks, or seeps into the ground, nostormwater fee is levied. If a green roof isinstalled, the stormwater fee is reduced by80 per cent to 0.09/m2 of green roof peryear. A green roof with high retention incursa charge of only 0.04 m2. There are alsofee reductions for retention ponds,infiltration systems and removal ofimpervious surfaces.

Property owners receive a water bill thatstates the amount of pervious andimpervious surface area on their property.The public work department oversees theprogram and the municipal tax servicesdepartment administers the fees — usedfor maintenance of the sewer system —and discounts.

The table below outlines the savings fromgreening a garage roof 50 m2 (538 sq. ft.).

The roof greening benefits are even greaterfor large developments. An industrial areawith 17,000 m2 (183,000 sq. ft.) ofconventional roof pays up to 7,480 a yearin stormwater fees. Greening this areareduces the annual fee to 1,496 a year.

Münster has reached policy phase 6, havingimplemented incentive programs toencourage green roofs and now using a feesystem to promote their use. The periodicrevision of the financial incentive programfor greening initiatives demonstrates the“continuous improvement” aspect of this phase.

Process to establish thepolicyIn the late 1970s, Münster established afinancial incentive program to subsidizeenvironmentally friendly initiatives. Theaim of the program, Improving the Quality ofLiving in the Downtown Core, was tooffset the increasing amount of asphalt andconcrete within the city and to improve thelocal climate. This program ran successfullyfor a number of years and led to increasedenvironmental awareness and knowledge

within the community. Building on thismomentum, Münster implemented astormwater fee in 1991 and established arainwater management program.1

The incentive program was merged withthe rainwater management program in

1993, which gave rise to a new program,Depaving and Greening. This programcombined aspects of both the downtownimprovement and rainwater programs. 26

In 1994, the city modified the program again,simplifying the guidelines and expandingthe area for the incentive. Measures toimprove rainwater retention and re-userainwater were also included. Thisprogram, Green vs. Gray, was allotted25,000 a year and subsidized green roofs

in the amount of 15 per square meter. 27

Program goals included stormwater sourcecontrol and improving the visuallandscape, primarily in the densely builtdowntown core. 28 Initiatives carried outdowntown (see figure 3 for outline of area)received an additional 20 per centfunding. Guidelines for this program areincluded at the end of this case study. Thisprogram ended in 2002 because offinancial constraints.

The stormwater fee is still in effect today.According to Gräser 29 this fee wasestablished in order to provide home andproperty owners with an incentive to dealwith rainwater at its source, whileconsequently reducing stormwater loadson the municipal sewer system. Moreover,it would create a just means of levying

stormwater taxes, forcing developers to payfor the stormwater their propertiesgenerate, while simultaneously reducingwaste water charges for apartment dwellersand other owners of small properties.

Stormwater fee — m2/yr Annual cost Yearly savings Savings after 40 years

Conventional garage roof €0.44 €22 — —

Extensively greened €0.09 €4.50 €17.50 €700

Table 10 — Stormwater fee reductions, garage roof 50 m2 (538 sq. ft.)

26 City of Münster. (2001). Grün gegen Grau. Entsiegelungs- und Begrünungsprogramm. Münster, Germany:Tiefbauamt.27 Ibid28 Gräser, B. (2002). Interview on May 6, 2002. Münster, Germany:Tiefbauamt.29 Ibid



EffectivenessThe Green vs. Gray program greened about1,000 m2 (10,700 sq. ft.) of roofscape eachyear. Funds for the program were fullyspent every year because of the highdemand. Applications were mainly fromhomeowners wanting to extensively greentheir garages or carports. By 2002,approximately 12,000 m2 (130,000 sq. ft.)of green roofs had been planted throughthe incentive program. 2

The stormwater fee has also beensuccessful, particularly evident by itsacceptance among residents. According tovon Trümbach, seeing the amount ofimpervious surface area on a water bill hasbeen a motivating factor in getting propertyowners to implement stormwater source-control measures. It is difficult todetermine how many green roofs wereinstalled as a result of the stormwater feealone, as the NRW incentive program is amajor motivator.

Lessons learnedEstablishing and managing a stormwaterfee is a substantial administrative task. Theamount of impervious surface on eachproperty is first assessed from informationsubmitted by property owners and verifiedby city staff. Impervious surface area canalso be determined through maps and aerialphotographs.

When a green roof has been installed,public works visit the site to verify projectcompletion and then inform the municipaltax department.

PredictionsThe installation of new green roofs isexpected to decrease in 2006, when theNRW incentive program expires. Thestormwater fee will still provide anincentive to install green roofs; however,coupling the fee with the incentive programhas proven to be a key combination.

Applicability to CanadaA stormwater fee holds potential as anindirect financial incentive for green roofsin Canada, especially where stormwatermanagement is a key motivator. Thisapproach is gaining considerablemomentum in Germany as moremunicipalities have implemented thisstructure to increase transparency in waterbilling by using the “polluter pays”principle.

Benefits of a stormwater fee includerevenue generation for municipalities, or atleast offsetting the cost of administration.Such fees can be implemented in new andexisting areas and would be especiallybeneficial in areas with combined sewersystems subject to overflow. Similar to

direct financial incentives, green roofsinstalled as a result of the fee are done sovoluntarily and longterm maintenance ofthe green roof is more likely.

A drawback to this approach is itsadministrative requirements. Municipalitieswith a large area will find it timeconsuming to determine the amount ofimpervious surface area in theirjurisdiction, whereas smaller municipalitiesmay find the time and cost associated withadministration to be exhausting.

Green vs. Gray programguidelines

1. General

A) Measures listed under heading three areeligible for funding. These measuresmust be within the area serviced byMünster’s combined and storm sewersystems.

B) Measures carried out within Münster’sdowntown core will receivesupplemental funding.

C) No one who receives funding from theNRW state program is eligible forfunding from the Green vs. Grayprogram.

D) The funding will be paid in a one-timeamount.

E) Regulations set out in localdevelopment plans, buildingordinances, the water bylaw and themonument bylaw must be heeded.

F) Applicants cannot make any legalclaims on the subsidy.

Figure 9 — Münster’s downtown core.



63

2. Individuals or Parties Eligible forFunding include:

A) Home or property owners

B) Tenants or lessees with the approval oflandlords.

C) Housing associations or other legalentities

D) Business owners (including legal entities)

3. Measures Eligible for Funding

A) The conversion of impervious surfaces(i.e. concrete, asphalt, pavement) intosurfaces that promote the naturalseepage of rainwater.

B) The establishment of playgrounds, aslong as no impervious surfaces arecreated. Exempt from funding are thoseplaygrounds required under existinglaw.

C) The planting of tall-stemmed,indigenous, deciduous trees appropriateto the location.

D) The greening of facades.

E) The filtering and retention of relativelyclean rainwater collected from rooftopson one’s own property (calculatedaccording to the area of the roof ).

1. For the retroactive redirection of rainwater into:

- the ground

- basins, or ponds withoutwaterproof liners

- infiltration ditches

- basin-infiltration ditches

2. For the construction of:

- water retention ponds,cisterns that hold at least 30 Lof water per m2

F) Green roof retrofits, or the roofgreening of a new building.

G) The construction of systems/unitsthat collect, filter and reuse rainwaterin flush toilets or for watering plants.

4. Conditions for Funding

A) Municipal funding will only be awardedif funding from federal or state (NRW)programs is not available.

B) Any systems constructed for themanagement or reuse of rainwater mustbe tech-nically sound and meet therequired standards.

C) Subsidies will only be granted if:

- measures have not yet beeninitiated. The city can,however, make exceptions formeasures that have alreadybeen begun, if adequate fundsare available,

- the ability of ponds orgrounds to facilitate naturalseepage has been approved bythe public water authorities,

- the system for the collectionand reuse of rainwater willnot be connected to awashing machine.

D) Subsidies will not be granted for:

- measures that qualify as taxwrite-offs,

- additions to existing gardens(i.e. plantings),

- measures that costs less than

€153.39.

5. Amount of Funding

A) Removal of impervious surfaces: €15.34per square metre of permeable surface.

B) Private playgrounds: €12.78 per squaremetre of permeable surface

C) Deciduous trees: the city will cover 50per cent of the costs, but no more than€ 11.29 per property.

D) Façade greening: the city will cover 50per cent of the costs for plants, labourand climbing aids.

E) Natural seepage and retention: €3.07per square metre of roof area drained.

F) Green roofs: €15.34 per squaremetre of greened area.

G) Systems that collect, filter and reuserainwater: €1,533.88 per unit.

H) Any of the above-mentionedmeasures that are carried out withinthe downtown core will receive anextra 20 per cent funding.

6. Application Process

A) Applications must be handed in beforebegin of the initiative.

B) The following must be included withthe application:

- Site plan at a scale of 1:500

- Site plan at a scale of 1:100,outlining proposed initiative

- Cost estimate

- Additional informationrequired for:

- Systems that collect, filterand reuse rainwater:questionnaire re methodology

- Natural seepage: documentssupporting the permeabilityof the ground and ifapplicable, the allowance forthis type of project.



7. Award of Grant, Payment

A) The municipality will judge theapplication based on its compliancewith the program regulations. Incertain cases, the approval of theapplication may only be given ifcertain conditions are met.

B) The payment of the subsidy will bemade once proof of payment has beensubmitted and the project has beeninspected and approved.

C) Should the costs of the project turnout to be less than stated on the costestimate, the appropriate reductionswill be made or the subsidy will bewithdrawn.

D) The subsidy amount granted cannotbe increased at a later date.

E) The subsidy may be withdrawn if theinitiative is not completed within oneyear after receiving approval of thegrant. The time period may beextended to two years if specialcircumstances exist and a writtenrequest is submitted.

8. Failure to Comply with Regulations

The municipality reserves the right towithdraw the subsidy, should theapplicant fail to comply with theregulations of this program, or withthe conditions necessary for approvalof the application.

9. Effective Date: July 1, 1994

City of MünsterApplication for a Municipal Subsidy from the Green vs. Gray Program

1. Property owner (name, address, telephone number)____________________________________

2. Applicant (name, address, telephone number)________________________________

3. Address (address at which the project will be carried out)_______________________

Proposed Measure Total Area (m2) Costs (€)Removal of impervioussurface

Playground

Planting of deciduous trees N/A

Façade greening N/A

Natural seepage

Roof greening

System to collect, filter andreuse rainwater

Total costs

The building is a:

____ single-family home ____ multiple-family home

____ commercial building ____ garage/carport



65

Declaration:

1. I am personally capable of financing the portion of the project not covered by the subsidy.

2. I am aware that the municipal subsidy may be withdrawn if:

� I fail to comply with the program guidelines

� I begin with the project before my application is approved, or if I do not com-plete the project within one year of receiving approval.

3. I am aware that I may not receive tax deductions for this project.

4. For green roofs: I declare that the loading weight of the roof to be greened is capable of supporting the proposed green roof system.

5. Included in this application is:

� A site plan

� A site plan at the scale of 1:100 outlining the proposed measures

� Cost estimate

� For systems to collect and reuse rainwater: completed questionnaire

� For seepage: documents supporting the permeability of the ground

� I agree to voluntarily provide my personal information, which is necessary to process this application.

Signature, Date _________________________

Frank von TrümbachTiefbauamtPublic Works DepartmentCity of Münster

0251/[email protected]

Key literatureCity of Münster. (2001). Grün gegen Grau. Entsiegelungs- und Begrünungsprogramm. Münster, Germany: Tiefbauamt.Gräser, B. (2002). Interview on May 6, 2002. Münster, Germany: Tiefbauamt.



09-05-06

Contact information

SummarySingapore’s green roofs fit in the government’s overall agenda of promoting the cityas the “Garden City.” Singapore is a small island with tropical temperatures andheavy rain. Because of the scarcity of land, high-density developments arecommon. Green roofs are seen to fit within the overall strategy to green suchdevelopments. Singapore officially calls this part of “Skyrise Greening.”

The driving force for Skyrise Greening and green roofs comes from the publicsector. Various departments within the government have worked to make this asuccess. Representatives of Singapore’s government have taken time to travelworldwide and have visited Germany and Canada to study green roofs.

The Singapore government did significant technical research related to life cyclecosting and energy benefits and has moved to phase 5 to include green roofs as anacceptable measure for density bonuses. Part of phase 5 is education and outreach;Singapore’s National Parks Board has produced a very detailed guide to green roofs.

DescriptionSingapore, located on one main island and about 60 small adjacent islands off thesouthern tip of the Malay Peninsula, has a population estimated at 4,240,000. Themain island is densely populated, especially in its south-central portion, thelocation of the central business district and the main port. The scarcity ofundeveloped land and green space creates a natural appreciation for greenery.


Case studies

Singapore

Key motivators Urban esthetics – “Skyrise Greening”


Champion Municipal

Longitude 1°N Latitude 104°E


27°C(80°F)


26°C (78°F)


2,250 mm(88 in.)

Map showing SingaporeScale 1:4,000,000


Green Roof pol ic ies worldwide—Singapore

67

Singapore’s total area is 699 sq km (270 sq mi). Singapore has a wet, tropicalclimate with an average annual rainfall of2,250 mm (89 in.). Most rainfall is duringthe northeast monsoon, from Novemberto March. During the southwest monsoonseason, from June to September, much ofthe rain falls in short, intense showers thatalternate with sunshine. Thunderstormsare frequent in April and October. Theaverage daily humidity is 84 per cent andat night, it is often more than 90 per cent.

There are no distinct seasons in Singapore.The temperature is much the same yearround. May and June are usually thesunniest months, while December andJanuary are slightly cooler and receive thegreatest amount of rain.

More than 60 per cent of Singapore Islandresidential, commercial and industrial.Jungles and swamps once covered it, buttoday only a small area of the central hillsretains its natural jungle cover. One of theisland’s largest remaining tracts ofundisturbed (primary) rain forest isprotected in the 163-hectare (405-acre)Bikut Timah Nature Reserve. Since theearly 1960s, land reclamation projects havebeen replacing Singapore’s once expansivecoastal mangrove forests with developedareas. The reclamation projects haveincreased the nation’s total area by 20 per cent.

Although Singapore has many shortstreams and several reservoirs, the countrylacks sufficient fresh water. About half itswater is imported from Malaysia bypipelines. Closely regulated governmentcontrols on emissions, effluents and otherwastes alleviate the effects of rapideconomic and industrial growth.

Key motivatorsSingapore is a clean and green city. Thecontinuous efforts to make Singapore a“Garden City” have resulted in lushgreenery throughout the island.

With Skyrise Greening, even the concretestructures of Singapore are expected toform the fabric of the Garden City increating a total garden environment. Themain driver is to market Singapore as a"City in a Garden.”

The appreciation of multiple benefits ofskyrise greenery include reduction ofurban heat island effect and reduction ofenergy use for cooling.

Description of policyIn general, rooftop greenery is promotedby not including certain portions of theareas used for greenery in the calculationof a building’s gross floor area. Thesepolicies are part of a regulatory frameworkimplemented the Urban RedevelopmentAuthority. Some of the specific measuresare outlined below:

Gross floor area (GFA)exemption for skyterracesSky terraces at intermediate levels of abuilding that are shaded by an overhang,floor or structure with open-sided areasavailable for communal activities orlandscaping with constant publicaccessibility are excluded from thecalculation of GFA. Sky terraces providecommunal spaces and greenery formedium or high-rise developments. Theyalso add visual interest to the buildingarchitecture and design.

Guidelines encouragingbalconies in residentialdevelopmentsEncouraging balconies in residentialdevelopments supports “Garden CityAmbiance.” The GFA of balconies inresidential developments can equal morethan the master plan (MP) allowable grossplot ratio (GPR) by up to 10 per cent. Tomake sure balconies are suitable for skyrise gardening, at least two sides must beopen. Service balconies used for dryingclothes are not accepted for GFA. Thispolicy applies to existing and newresidential buildings. An amendment tothis policy includes mixed use and hoteldevelopments.

GFA exception forcovered roof top areas,public thoroughfaresand public spacesTo encourage more interesting roof designand better use of rooftops, GFAcalculations exlcude:

� Rooftop pavilions

� Sky terraces at intermediate levels of abuilding that are shaded by anoverhang, floor or structure with open-sided areas available for communalactivities or landscaping with constantpublic accessibility.

GFA exemption forcovered communalareas and shadow areasfor the developments To encourage more covered landscapedcommunal areas and greenery, certain areasare exempt from GFA computationsubject to conditions:



� Communal landscaped areas on the firststorey.

� 50 per cent must be enclosed andaccessible for community activities.

� Must be landscaped with a variety ofvegetation and add substantially to thegreenery of the environment.

� Communal sky bridges linking blockswithin single development.

� Covered leftover landscaped communalspace at the first storey created bydriveways or drop off points.

� Must be a communal area andlandscaped.

Guidelines for rooftoppavilionsTo promote activities on rooftops, a GFAexemption can be granted to buildings thatare not landed housing developments.Several requirements must be met in orderto obtain this exemption:

� Applies to single storey (under 6 m [20ft.] high) with a non-bearing roof coverand pavilions with a maximum of 50per cent of perimeter enclosed.

� The pavilion can be partially attachedto the main building with 50 per centof its perimeter attached.

� Pavilions coverage must be at least 50per cent landscaped and must only beaccessed from common areas and usedfor communal activities or as part oflandscape features.

� The pavilion will not be counted asGFA if it is used for commercialpurposes.

� Does not apply to landed housingdevelopments since there is nocommunal use of pavilions there.

Research andeducational programsThe National Parks Board organizes a seriesof skyrise garden exhibitions to encouragegardening in high-rise environments,including on rooftops. The HousingDevelopment Board and the National ParksBoard are working on research projects onapplying green roof technology on publicresidential buildings.

The National Parks Board publishes a seriesof publications on Skyrise Greening to promote the benefits of greening the high-rise environment. More information onthese pub-lications is available on itswebsite at http://www.nparks.gov.sg

Process to establishpolicyThe relaxation of GFA regulations resultfrom a desire to improve skyrise greenery inSingapore.

The research and educational programshave been directed through demonstrationprojects and the development of twohandbooks. Information from the researchhas been made available to the publicthrough the downloadable handbook at theNational Parks Board website and seminarstargeted at industry players.

EffectivenessThere is no available measure ofeffectiveness. Informal observations indicatethat there is a trend for rooftop gardens innew commercial and residentialdevelopments. One measure of increasedgreen roof construction is the presence ofgreen roof technology suppliers in Singapore.

Applicability to CanadaFrom a geographic and climate perspective,Singapore does not have many similaritiesto Canadian jurisdictions. Nonetheless,Canadian jurisdictions could adapt theapproach in areas with high-densitydevelopment or where green roofs mightincrease real estate value. Providingincentives through relaxed developmentrequirements to promote green roofs wouldwork where green roofs can provideamenity space or where green roofs canimprove the esthetics of the development.

Relaxing the development requirementsand a strong educational and promotionprogram — key features of Singapore'ssuccess in green roofs — could apply tomany Canadian jurisdictions.



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Mr. Seow Kah PingDeputy DirectorPhysical Planning/PolicyUrban Redevelopment AuthoritySingapore6321 [email protected]. Tan Puay YokAssistant Director Research DivisionNational Parks BoardSingapore6471 [email protected]

Key literatureNational Parks Board, Singapore. (2002). Handbook on Skyrise Greening in Singapore. National Parks Board & Centre for TotalBuilding Performance, University of Singapore. Retrieved March 2005, fromhttp://www.nparks.gov.sg/publications/handbook_sg.shtml

National Parks Board, Singapore. (2005). Skyrise Greenery. Retrieved March 2005, fromhttp://www.nparks.gov.sg/gardencity/skyrise.shtml

Urban Redevelopment Authority (URA), Government of Singapore. (2005). Handbook on Gross Floor Area. 2005 Edition.Retrieved March 2005, from http://www.ura.gov.sg/circulars/text/dcdgfahb_d0e4.htm

Weng, H.W. (2004). Green Roofs in Singapore (171-176). Presented at the International Green Roof Congress, Nurtingen,Germany.



09-05-06

Contact information

SummaryGreen roofs have a long tradition in Stuttgart. The first green roof was built in the1920s and still exists today.

Stuttgart’s location in a valley basin, its mild climate, low winds and surroundingindustrial activity made it susceptible to poor air quality as early as the 1970s.Built forms on the valley slopes have made the situation worse by preventing airfrom moving through the city, which contributes to the urban heat island effect.

City officials set out new zoning and building regulations to improve air quality,including increasing the amount of green space. Green roofs, championed by thehead of the planning department, were recognized as a way to improve air quality.

In 1985, Stuttgart became the first German city to include green roofs in its localdevelopment plans. In 1986. the city set up a financial incentive program that isstill in effect . Stuttgart also greens publicly owned buildings as a demonstration ofits commitment to green roofs. Stuttgart has reached policy phase 6 as the City isworking on improved quality control and inspection.

Stuttgart’s incentive program is successful. Funds are exhausted each year.

DescriptionStuttgart is the capital of the state of Baden-Würtemburg and has a population ofapproximately 600,000 . The city is located in the centre of an industrial region ofmore than two million and is well-known for its high-tech industry


Case studies

Stuttgart, Germany

Key motivators Air quality

Policy phase 6 — Continuous improvement

Champion Municipal

Longitude 48°68' N Latitude 9°21' E


18°C(64°F)


-1°C (30°F)


731 mm(28.78 in.)

Map showing Stuttgart, Germany Scale 1:4,000,000


Green Roof pol ic ies worldwide—Stuttgar t , Germany

71

Geographically, Stuttgart is extendsthrough two valleys (ringed with vineyardsand forests) lying at right angles to eachother. The main part of the city issurrounded by steep slopes on three sides,with the rest of the city located along theopen valley of the Neckar River.

Stuttgart has a mild, temperate climatewith warm summers, moderate enough toallow wine production on its valley slopes.Wind speeds throughout the city aregenerally low, which along with the urbanheat island effect, contributes to poor airquality (at times) and mild climaticconditions. Stuttgart’s climate is mostlyaffected by altitude. The downtown core,at an elevation of 207 m (679 ft.), canhave winters with no snow coverage, whilehigher regions at 549 m (1,800 ft.) canhave up to 54 days of coverage. Onaverage, temperatures dip below zerodegrees Celsius 77 days a year.

Table 11 — Land use, Stuttgart

Key motivatorsStuttgart’s industrial activities and locationin a valley basin make it especiallysusceptible to poor air quality. A study inthe early 1990s examining how landforms

and structures affect the movement of airthrough the city identified thesurrounding slopes, forests and agriculturalareas as major sources of fresh air for thecity. The pollution problem resulted fromincreased urban growth onto valley slopes,which replaced vineyards and trees withbuilt form.

These findings had a significant impact oncity planning. The city established an envi-ronmental department to assess proposeddevelopments and their effect on the localclimate. The city’s zoning plans identifiedareas that are key to the health of the localclimate or that lacked sufficient plant life.Planners were challenged to improve theurban climate, which meant preventingdevelopment in areas vital for fresh airflowand prohibiting new buildings where theywould hinder the movement of air.Planners were also called upon to createnew green spaces to improve the climate.

Description of thepolicyThe City of Stuttgart promotes green roofdevelopment by:

� greening public buildings,

� offering a financial incentive forbuilding/homeowners and

� regulating green roofs in localdevelopment plans

Its long green roof tradition placesStuttgart in phase 6 of policy developmentas the city continues to improve its currentprograms with quality control andinspection measures.

Public buildingsTo demonstrate its commitment to greenroof development and environmentalimprovements, Stuttgart has been greeningthe roofs of public buildings since 1986. Itsets aside 90,000 annually, with mostgreen roofs being installed when the roofis due to be replaced.

Figure 10 — Extensive green roof onpublicly owned parking garage inStuttgart.

Direct financialincentiveStuttgart’s established it financial incentiveprogram for green roofs in 1986. It isadministered by the city’s planningdepartment. The program, which has€51,000 available a year, pays for 50 percent of the costs, or up to a maximum of€17.90 per square metre.

To apply for the grant, an applicationaccompanied by a site plan, green roofdesign plan and estimated costs. Freeconsultations are available from the cityparks and cemeteries department. (Seepage 98 for the program guidelines.)

The city also produces a “how to”brochure about roof greening. It coverstopics such as: benefits, extensive andintensive, weight and waterproofing, green

Use Percentage

Buildings 29.3%

Traffic 14.3%

Agricultural 24%

Forest 23.8%

Recreational 5.3%

Other 3.1%



roof systems, choosing plants (with lists)and maintenance. The brochure outlinesspecific criteria and functions a green roofshould have, such as 30 per cent waterretention capacity, and gives the FLL as thedesign standard.

Green roof regulation Local development plans first regulatedgreen roofs in 1985, in an industrial areacalled Weiler Park. The regulation statesthat all flat roofs and roofs sloped eight to12 degrees must be extensively greenedwith a minimum growing-medium depthof 12 cm (4.7 in.) Specifying growing-medium depth is an important componentof the regulation, as it is a way to ensurecompliance later .

Green roofs can also be regulated throughthe federal Ecological Compensation andReplacement Measure, which states thatenvironmental disturbances must beavoided, minimized or mitigated.

Figure 5 shows an ecological compensationand replacement analysis conducted inStuttgart-Plieningen. This analysis assignsvalues to various ecological features of a sitebefore and after development. Thedifference between the two numbersdetermines the extent of mitigationrequired.

The area before the construction had avalue of 268,000 points; after the proposeddevelopment it would have been 193,250points — even after mitigation measures —because of the increase in impermeablesurfaces. According to this assessment, thedeveloped area will contain only 72 percent of the originally occurring biologicalfeatures, requiring that a replacementmeasure be carried out at another location.

This may be achieved through greening ornaturalization measures in another area inthe city.

Note that green roofs are assigned a valueof 1, whereas conventional roofs areallocated a value of zero. If the green roofshad not been included in this developmentproject, the developed area would only havehad a value of 164,450 points, resulting inonly 61 per cent of the original biologicalfeatures being accounted for, a difference of11 per cent . Green roofs present a uniquecompensation opportunity by allowingmitigation and replacement measures to beconducted on site.

Trade-offs or compromises with developersare a common element of the roof greeningprocess. For instance, exceptions can bemade for architectural reasons, such asarched roofs, which although technicallycan be greened, are exempted from the

regulation for esthetics. Compensationtypically involves installing vegetationelsewhere such as planting trees at grade.

Process to establishpolicyIn Stuttgart, the notion of greeningrooftops was first met with skepticism.Common arguments against green roofswere the higher upfront capital costs andthe fear of water leakage. This was evidentin the case of Weiler Park, the first areawhere green roofs were regulated for all flatroofs.

The development of Weiler Park was acontroversial issue because of its proposedlocation on prime agricultural land. It wasthought to be too expensive and incapableof attracting companies due to theadditional capital costs. Through a series ofcompromises, which included extensively

Courtesy of the City of StuttgartFigure 11 — Intervention-mitigation analysis conducted in Stuttgart-Plieningen(translations by author)



73

greening all rooftops, the developmentreceived approval. The green roofs were toimprove the microclimate, manage stormwaterrunoff and improve the esthetics of thedevelopment. The industrial park issituated in a small hollow at the crossroadsof two major highways and a railway linethat render its roofs entirely visible.

The now-retired head of the planningdepartment, Albert Ackermann,championed the green roof movement inits early days, attending all public, boardand developer meetings to address questions andconcerns. His persuasive powers, persistenceand political support are responsible forStuttgart’s green roof success.

Effectiveness All approaches promoting green roofs inStuttgart, have proven successful. To date,105,000 m2 (1,130,210 sq. ft.) of publicroofscapes have been greened.

The financial incentive program hasgreened 55,000 m2 (592,000 sq. ft.) todate. The demand for funding is high andoften applications have to be declinedbecause of insufficient funds.

There is no data on the amount of roofscapegreened as a result of the building regulations.

Lessons learnedRegulating green roofs should be approached withcaution. While it is the most effective methodby which to increase the amount of roofscapegreened, it can also can be detrimental t inthe long run as mandatory green roofs maynot be properly maintained. A neglectedgreen roof can give the roof greeningmovement a negative image.

It is important that the buildingowner–developer perceive the green roof to

be an asset as opposed to something that issimply being forced upon them. When thegreen roof is visible, or can be used,acceptance (and the likelihood ofmaintenance) is much higher.

Applicability to CanadaThe financial incentive program andregulations for green roofs have had aprofound effect on green roof developmentin Stuttgart. Furthermore, the city’scommitment to greening public roofscapeshas demonstrated its trust and belief in thetechnology.

Financial incentiveprogramsOn the positive side of incentive programs,subsidies target parties who are genuinelyinterested in the idea and therefore morelikely to properly maintain their greenroofs. The incentive program can be targetedto specific areas or building types and canbe used to meet various environmentalneeds. This type of program would workwell for priority renewal or densely builtareas as well as for retrofit projects.

On the other hand, financial incentivesrequire a significant investment by thejurisdiction if the incentive is to beworthwhile. There should be a certain levelof public awareness to ensure adequateinterest in the program, which could becoupled with a marketing campaign.Municipalities should also be prepared toprovide support to program applicants.This might include an initial consultationsession, basic information on the benefits ofgreen roofs, a list of local contractors andsuppliers and so on.

Regulating green roofsRegulating green roofs is an option in theface of budget constraints. In Stuttgart, thisapproach is used for new development, as itis not suited for retrofit projects.Regulations can be used to meet specificenvironmental goals by specifying the typeof green roof that must be installed and isthe most effective way of ensuring a targetamount of roofscape is greened.

Demonstration projectsCanadian municipalities interested inpromoting green roofs may considergreening public buildings to demonstratetheir commitment to and trust in greenroof technology. Accessible green roofdemonstration projects are an excellent wayto raise awareness and educate. An outreachand marketing campaign that directs mediaattention to the demonstration would helpensure adequate publicity. Campaignscould be targeted to different groups suchas homeowners and developers, to addressconcerns specific to the group.

Guidelines — Greenroof incentive program

1. Goals of the Subsidy Program

The goal of this program is to increasethe aesthetic quality in densely populatedand compact urban areas in Stuttgart,as well as to improve the climate and itsurban ecology. To facilitate these goals,the City of Stuttgart will providesubsidies for the roof greening onprivate buildings within the limits ofthe budget set aside for this purpose.

2. Areas Eligible for Subsidies

The subsidy program applies to the entire cityof Stuttgart.



B) Areas not eligible include:

- Areas designated for rehabilitation asdesignated in the urban developmentsubsidy bylaw

3.Type of Support

A) Consulting services are available tobuilding owners, tenants or othereligible persons.

B) Subsidy grants.

C) Approaching building owners in possessionof buildings suited for roof greening.

4. Preconditions for the Grant of aSubsidy

A) Roof greening measures that consist ofa growing medium-based, continuousstructure are eligible for funding (i.e.container gardens are not eligible).

B) Not eligible for subsidies are:

- buildings that require greenroofs as designated in thelocal development plan,

- plants in containers or potsor other similar measures,

- gravel layers, slabs, timberor other similar material forthe construction of roofterraces

- measures that have beeninitiated before receivinggrant approval.

C) Measures must not conflict withbuilding regulations, building codes orwith the bylaws for the protection ofhistorical buildings. Any necessarydocumentation for the authorization ofthe measure must be submitted beforeapproval of the grant.

D) Proof that financial resources, inaddition to the grant, are available forthe proposed green roof must besubmitted.

E) Any measures funded may not be usedas grounds to raise rents.

F) Property owners and other eligiblepersons must be committed tomaintaining the subsidized green rooffor at least 10 years after itsinstallation.

G) Applicants must transfer allresponsibilities associated with thesubsidy to their successors in interest.

5.Amount of Subsidy

A) The subsidy will cover 50 per cent ofthe actual costs, but no more than17.90 /m2 ($27.30 Cdn/m2).

B) Sales tax will not be covered by thesubsidy, if the applicant qualifies foradvanced tax deductions.

Individuals or parties eligible forfunding Include:

A) Property owners.

B) Those with legal rights to use the property.

C) Tenants with the approval of theirlandlords.

6. Priority will be given to:

A) Natural persons.

B) Those that demonstrate an acute need.

C) Measures especially capable ofimproving ecological conditions andthe urban visual landscape in asustainable manner.

D) Measures that are combined withothers to improve environmentalconditions.

7.Applications

A) Applicants must complete all requiredforms and submit the application tothe Department of Parks andCemeteries.

B) The following must be submitted withthe application:

- Site plan at a scale of 1:500(3 copies)

- A plan outlining theproposed design at a scale of1:100. The plan must beaccurate enough so that itmay be used at a later date todetermine whether the designof the green roof is incompliance with theguidelines.

C) Documents detailing the cost of theproject.

D) Documentation from the land registryverifying ownership.

E) Proof of authorization or legal rights tothe use of the property in the eventthat the property owner is notsubmitting the application.

8.Application Approval Procedures

A) If the all the eligibility criteria havebeen met, provisional approval will beissued.

B) After the green roof has been installedand after all receipts haven beensubmitted, an appointment for theinspection of the green roof must bemade with the Department of Parksand Cemeteries.

C) Receipts must be submitted to thedepartment of parks and cemeteries nolater than three months aftercompletion of the green roof.



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D) After the green roof and receipts have been approved, final grant approval is issued.

E) Payment of the subsidy will be made according to the availability of funds in the order that the final grant approvals were made.

F) Advancements of up to 75 per cent of the grant amount as stated in the provisional approval can be issued upon presentation of proofof grant approval.

G) Representatives from the Department of Parks and Cemeteries may supervise the implementation of the green roof. The applicantmust disclose all information re-quested by the supervisor upon inspection.

H) The subsidy must be repaid if the conditions of the grant are not met or if the regulations are violated. The subsidy must be repaid atthe time of annulment of the final grant approval. The sum is subject to an interest rate three per cent above that of the current bankrate, with an annual rate of at least 7.5 per cent.

9. Exceptions

Exceptions to the technical section of these guidelines may be made, if they serve to enhance the goals of this subsidy program.

10. Effective Date

These guidelines come into effect a day after their publication (November 1986).

Hermann DegenCity Planning and RenewalCity of Stuttgart(07 11) 2 16-29 [email protected] DövelingDepartment of Parks and CemeteriesCity of Stuttgart (07 11) 2 16-53 [email protected]

Key literatureGreen Roofs, But How?. (2003). City of Stuttgart: Department of Parks and Cemeteries.Evert, K-J. (2004) Ökologisches Bauen mit Gründächern. Presented at the International Green Roof Congress, Nürtingen,Germany.Stender, I. (2002). Why Spend Public Money on Green Roof Infrastructure?. Toronto, Ont.: Faculty of Environmental Studies – York University.

Contact information

SummaryThe City of Tokyo went quickly into an advanced phase of green roofpolicymaking. Tokyo, with its temperate climate and plentiful rain, has been seeingan ever-increasing effect of rising temperatures from urban heat island effect. Therise in temperature is considered to be so serious issue that the Tokyo MetropolitanGovernment (TMG) has readily adopted policies requiring green roofs onbuildings, without much time spent on phases 1 to 4 of policy development.

The TMG has mandated green roofs on a percentage of the area of every newbuilding . Failure to provide green roofs results in a penalty for developers.

Roof gardens on buildings have always added high value to building where suchspaces have been publicly accessible. However the mandatory requirement by theTMG has created a necessary reason to add green roofs on all new developments.It is estimated that in the first year after the passage of this law in 2001 the area ofgreen roofs doubled.

DescriptionTokyo is Japan’s capital and the most populated metropolitan area in the world,with 12 million people. Tokyo proper has a population estimated at 8,100,000. Itis at the head of Tokyo Bay, midway along the eastern coast of Honshu Island. Thecity occupies most of the southern part of the Kanto Plain, the largest area of flatland in Japan.


Case studies

Tokyo, Japan

Key motivators Urban heat island


Champion Municipal

Longitude 35°N Latitude 139°E


26°C(79°F)


4°C (39°F)


1,500 mm(59 in.)

Map showing Tokyo, JapanScale 1:4,000,000


Green Roof pol ic ies worldwide—Tokyo, Japan

77

The climate is temperate. There arefrequent typhoons, with heavy rain, inSeptember and October.

Tokyo Metropolis covers an area of about2,200 sq km (about 840 sq mi). The restof Tokyo Metropolis is a large suburbanarea stretching to mountains in the westand two chains of small islands to thesouth in the Pacific Ocean.

Key motivatorsIn the last 100 years, the averagetemperature in Tokyo has increased byabout 3°C, more than five times theincrease in the world's average meantemperature. The effect of this urban heatisland is an increase in smog alerts, energyconsumption for cooling and heat-relatedillnesses and deaths.

Another factor related to the urban heatisland effect and which affects Tokyoculturally is the earlier arrival of the cherryblossom season. Plant species native totropical weather areas and never beforeseen in Tokyo have also emerged locally asa result of warmer weather.

Description of policyTokyo has at least two measures topromote green roofs on buildings:

4. As part of rooftop greenery measures,the TMG has passed an Ordinance onNatural Preservation, sometimesreferred to as Ordinance onEnvironmental Preservation,” thatmandates that a certain portion of theroof on new developments be greened.Tokyo requires at least 20 per cent of aroof to be greened in newdevelopments or extensions to existing

developments larger than 1,000 m2

(10,764 sq, ft.) for privatedevelopments and 250 m2 (2,691 sq.ft.) for public developments. Failureresults in a penalty of approximately200,000 yen ($2,000 US).

5. As part of a green building program,TMG also has a voluntary measure inplace that encourages new buildingdevelopments to submit a project planthat states the environmental measuresincorporated in the buildings. It alsorequires the assessment of thedevelopment in compliance withTokyo's ordinance on environmentalpreservation.

Process to establishpolicyTokyo’s severe urban heat island effectforced the municipal government torespond. Unlike European jurisdictions,the TMG instituted green roofrequirements without much research orcost justification. The TMG was able tocreate regulations based on the pre-cautionary principles without the typicalobstacles to policy development, such asresearch and public support.

A 2001 report by the Tokyo EnvironmentMinistry confirmed the correlationbetween the high percentage of heat-absorbing surfaces and the city’s warming.Widespread greening efforts, such as treeplanting, park expansion and green roofswere considered potential mitigatingsolutions.

After a successful demonstration project,educational seminars targeting thedevelopment community and a subsidytrial in one ward, the TMG amended the

Natural Conservation Ordinance toinclude among other measures, mandatoryrequirements for green roofs on newconstruction.

To promote the legislation the TMG alsoconstructed a green roof demonstrationproject on the Tokyo Council Buildingand other facilities.

EffectivenessIn the first year after the passage of thelaw, total net area of green roofs almostdoubled from 52,400 m2 (564,000 sq. ft.)in 2000 to over 104,400 m2 (1.1 millionsq. ft.) by the end of 2001. At first glance,this success can be attributed to the lowbase requirement for coverage. However,actual implementation on some of theprojects reveals that many de-velopersinvested in the creation of large roofgardens much larger than required by thelaw. The success of this initial regulationhas motivated the city to raise target levelsfor rooftop greenery to nearly 12.5 millionm2 (130 million sq. ft.) as part of theeffort to increase green space in the city.

The government of Japan is followingTokyo's lead on green roof legislation and

in 2005 required greening of at least 20per cent of roof areas of all new buildings.


Green Roof pol ic ies worldwide—Tokyo, Japan

Lessons learnedThe documented evidence suggests thatthe TMG policy has worked well for newbuildings. There does not appear to beany record of impact of the policy onexisting buildings and it is not clear howthe targets for greening will be achieved.

There is some anecdotal evidence that thepolicy may not be working as plannedsince on many new developments thepenalty is small compared to the extra costit would require to implement the green roof.

PredictionsCurrently scientists at local universities areinvestigating how green roofs can most ef-fectively be applied to mitigate the urbanheat island effect. This retroactive researchmay affect future regulations andgovernment investment in green roofdevelopment.

Habuka, YumiMetropolitan GovernmentBureau of the EnvironmentTokyo, Japan 81-3-5388-3432Makato, MuraseDepartment of Environmental ProtectionTokyo, Japan 81-3-3611-0573 or [email protected] [email protected] Toshiko ChibaMetropolitan GovernmentTokyo, [email protected]

Contact information

Key literatureAkagawa, H. (2003, April). Greening of Buildings in Japan-Recent Developments. Pre-sented at the Australian Institute of Landscape Architects’ Greening Cities a new UrbanEcology Conference, Australia. Retrieved March 2005, fromhttp://www.aila.org.au/nsw/greeningcities/default.html

Brooke, J. (2002, August 13). ‘Heat Island’ Tokyo is in Global Warming’s Vangaurd. NewYork Times. Retrieved March 2005, from http://www.greenroofs.com/pdfs/archives-nyt_brooke_heat_island_tokyo.pdf

City of Tokyo, Bureau of the Environment. (2003). The Environment in Tokyo. RetrievedMarch 24, 2005, fromhttp://www.kankyo.metro.tokyo.jp/kouhou/english2003/index.html

Mikahami, T. (2005). Tokyo: Cooling Rooftop Gardens. In Earth Pledge, Green Roofs:Ecological Design and Construction (130-134). New York, New York: Schiffer PublishingLtd.

Shobhakar, D. (2003). Assessment of local strategies for countering greenhouse gasemissions: Case of Tokyo. Japan: Urban Environmental Management Project, Institute forGlobal Environmental Strategies (IGES). Retrieved March 2005, fromhttp://www.iges.or.jp/en/ue/pdf/dhakal/dhakal_tokyo.pdf



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Canada Mortgage and Housing Corporation 79

Part 3 — More case studies


Canada

DescriptionCalgary, at the junction of the Bow and Elbow rivers, is Alberta’s largest city. Thecity’s high elevation and position on the leeward side of the Rocky Mountainfoothills gives Calgary a unique climate. Its best-known weather feature is theChinook winds — Pacific-warmed systems that develop over the Rockies — whichsettle over the city 10 to 20 times each winter and can raise temperatures morethan 20°C in a few hours. They often melt all the snow cover and their strong, drywinds desiccate the landscape. Winter returns suddenly and unprotected plantsoften die.

In the summer, Calgary has little precipitation. The number of days with minimalprecipitation is 111 and the number of days with measurable sunshine is 332.With an average of 2,314 hours of sunshine, Calgary has been dubbed theSunshine City.

The extreme summer and winter temperature swings and low precipitation are amajor challenge for green roofs. With experience from green roof installations,roofing manufacturer Soprema recommends at least 153 mm (6 in.) of growthmedium to help hold moisture.

The growing season averages 112 frost-free days, short even when compared withother Alberta centres. The soil in and around Calgary is typically an alkaline, clay-based composition, which can result in poor drainage and poor nutrition forplants. Although clay is rich in nutrients, the alkalinity of the soil, increased bywatering with potable water, binds the nutrients and makes them unavailable forthe plants. It is fair to say that gardening is challenging in Calgary.


Case studies

Calgary, Alberta

Longitude 51º03’N , Latitude 114°05'W

Elevation 1,084 m (3,556 ft.)


15.2°C(60°F)


4.4°C (40°F)


320.6 mm(12.6 in.)

Average snowfall126.7mm

(5 in.)

Area722 km2

(279 sq. mi.)Population 930,000

Liliana BozicWater Quality Research EngineerWaterworks and Wastewater, City of Calgary(403) [email protected] RossSustainability Coordinator, CPV Group Architects & Engineers,Calgary(403) [email protected] or [email protected] (Sonny) TomicSenior Urban DesignerPlanning, Development and AssessmentDepartmentCity of Calgary(403) [email protected] WeckmanPlannerPlanning, Development and AssessmentDepartmentCity of Calgary(403) [email protected]

Contact information


Green Roof pol ic ies worldwide—Calgar y, Alber ta

The city, known as Canada’s energycapital, is growing rapidly and recentlyovertook Edmonton as the largest city inAlberta. The main industry today is oiland gas, which drives a thriving economyand attract many high-tech industries.Agriculture is a key industry in thesurrounding areas.

Key motivatorsThe motivators are stormwatermanagement, green building practices andsmart growth, as urban sprawl is an issuebecause of the city’s rapid growth. There isalso a desire to make the inner city moreliveable and attractive.

There is a push for green roofs in the citycore and Beltline District (which bordersthe downtown), directed by the CityCentre Plan as a way to revitalize anddevelop green space.

Description of thepolicyThe city is considering a number of publicbenefits as being eligible for incentives andbonuses. The City Centre Plan mayinclude green roofs as a public amenity for

increased urban green space. Other publicbenefits might include open space,streetscape or “lanescape” improvements,heritage resources, redevelopment of keysites, affordable housing and othercommunity development initiatives.

Process to establishpolicySeveral activities could encourage moregreen roof construction.

Kerry Ross, a Calgary resident andarchitect, championed a local green roofdevelopment workshop, co-hosted byGreen Roofs for Healthy Cities, in 2003.She was inspired by the potential of greenroofs after working on a green roof designfor a building in Banff and attending asimilar workshop in Vancouver.

The City of Calgary and CMHCsupported the workshop. Although thereas been no coordinated follow up or actionon creating the Workshop’s suggested citytask force to further green roofs, GreenRoofs for Healthy Cities and CMHCorganized a Green Roof 101 course inOctober, 2004.

The city has taken some action to promotegreen roofs as a way to mitigatestormwater runoff, monitor the climaticeffects on plants and create public amenityspace. Sonny Tomic and Liliana Bozic ofCalgary’s city staff are working with adeveloper on a mixed-use residential,inner-city project that they hope willfeature green building practices and agreen roof.

Calgary Technologies Inc. (CTI), a high-tech focused, non-profit organization,offered its building as a test site. CTI isworking with Ms. Ross, Soprema Canada,Studio T Design Ltd. and Alberta’sClimate Change Central.

The project is about 279 m2 (3,000 sq.ft.) of roof, which is visible from manyvantage points in the building, outside apublic link between two wings of the CTIbuilding. Environment Canada’sEcoAction, Shell Environment Fund,Climate Change Central and other privatesector donors contributed enough fundingto proceed with the first phase ofconstruction in September, 2005.Soprema, a major supporter, donatedgreen roof components.

In Phase 2, which will go ahead whenfunds are available, will be a monitoringand data acquisition system. The City ofCalgary will monitor the stormwaterrunoff. The demonstration roof will testgrowth mediums of 101, 152 and 203mm (4, 6 and 8 in.) with different plantsin each plot. Windward and leeward roofswill enable the monitoring of wind andbuffering. The demonstration project isessential to determine how well green roofstolerate Chinooks, to monitor wateringrequirements for native plant species andto find the optimal depth of growthmedium.

Other recent events and City reports showsome consideration of green roofs as a wayto control stormwater and create greenspace in the city core and Beltline District.In particular, the city has created asustainable building policy that proposes aLEED Silver rating as a requirement fornew facilities and additions larger than465 m2 (5,000 sq. ft.)

A 2004 urban structure plan, whichexamined the redevelopment of areas ofdowntown Calgary, identified green roofsas one way of bringing green space intothe city core.


Green Roof pol ic ies worldwide—Calgar y, Alber ta

83



09-05-06

In 2004, the city launchedimagineCALGARY, a two-year visioninginitiative. This is an initiative to create along-term sustainability vision and willresult in a 100-year vision with strategies toreach 30-year targets. The city plans topresent the long-range community visionand plan at the United Nations WorldUrban Forum in Vancouver in June, 2006.

Effectiveness Until a demonstration green roof is builtand monitoring equipment installed therewill be a lack of climate-specific data forCalgary. Interest in and uptake of greenroofs in Calgary has primarily been led bybuilding practitioners, owners anddevelopers. Several recently built greenroofs are in housing developments (single-family houses and MURBS), community-focused and mixed-use buildings.

City projects with green roofs include theWater Centre and the Pine Creek WaterTreatment Facility. The Water Center is a13,000 m2 (140,000 sq. ft.) office buildingfor departments associated with water andwaste water. Its environmental goal is tomeet and exceed a LEED Silver rating asmandated by the City of Calgary formunicipal buildings. It will have a greenroof over its truck maintenance wing.

The Pine Creek Water Treatment Facilitywill be built over many years. A waterresearch centre is planned withparticipation from the University ofCalgary and other stakeholders. Greenroofs are planned for a number of buildingson the site.

Lessons learnedEngagement of the city, developers,builders and the public requiresconcentrated effort before they considergreen roofs as a means to mitigatestormwater runoff and provide urban greenspace.

The futureSuccess is anticipated for the demonstrationgreen roof and the green vision that willevolve from the ImagineCALGARY andCity Centre Plan initiatives. The growinggrass-roots awareness of the environmentalbenefits bodes well for a bright future forgreen roofs in Calgary.

LiteratureCity of Calgary. (2000). Stormwater Management and Design Manual. Retrieved fromhttp://www.calgary.ca/docgallery/bu/wwd/stormmanual.pdf

City of Calgary. (2004, March). Urban Structure Plan. Presented at Urban Structure Plan Workshop. Fort Calgary, Alta.

Retrieved from http://www.calgary.ca/DocGallery/BU/planning/pdf/usp_e_zine_2.pdf

City of Calgary. (n.d). ImagineCalgary. Retrieved from http://www.imaginecalgary.ca/index.php

The Calgary Horticultural Society. (1996). The Calgary Gardener.

DescriptionHalifax, on the Atlantic coast of Nova Scotia, is situated on a protected bay. Themunicipality has a wide variety of industries, such as shipbuilding and shippingand support to the offshore oil industry. Halifax is also the regional hub for theprovincial government and banking industry.

Weather patterns are extreme and can vary by 30 or more degrees in 24 hours. Thecoast is occasionally subject to hurricane winds. Overall though, the climate ismoderate, with lots of cloud cover and fog that disperses the sunlight.

Key motivatorsHalifax Regional Municipality (HRM) is working on a 25-year environmental planthat covers a variety of topics.

Green roofs are seen as a way to reduce commercial air conditioning costs andstormwater runoff. HRM is considering the promotion of sustainable constructionand LEED requirements for new buildings. Green roofs would help meet thosestandards. Kendall Taylor, a local champion for green roofs, notes that developinga long-term environmental plan creates greater awareness of other environmentalissues and solutions at different levels and sectors.


Case studies

Halifax, Nova Scotia.



17.4°C (63ºF)Average wintertemperature

-3.2°C (26ºF)


1,356 mm(in.)

Averagesnowfall

151.8 cm(in.)

Area79.2 km2(15,444 sq. mi.)

Population 400,000

Stephen KingManager–Senior AdviserSustainable Environment ManagementOfficeHalifax Regional Municipality (902) [email protected] Lundholm, PhDAssistant Professor, Biology Department/EnvironmentalStudies ProgramSaint Mary’s University(902) [email protected] S. Taylor MRAICCaGBC DirectorLEED-Accredited Professional(902) [email protected]

Contact information


Green Roof pol ic ies worldwide—Hal i fax , Nova Scot ia .

85

Description of thepolicyHRM has initiated discussion, within the25-year plan, to encourage green roofconstruction. A recent green roofworkshop discussed the idea of usingincentives. Now, the drive to encouragegreen roofs comes from the private sectorwith support from the HRM, which wasfully involved in the green roof workshop.

Process to establishpolicyKendall Taylor is a LEED-accreditedarchitect and a director with both the localand national Canada Green BuildingCouncil. Mr. Taylor attended the 2003Green Roof Conference in Chicago andreturned excited about the benefits greenroofs could bring to Halifax. He initiatedthe idea of hosting a local Green Roofs forHealthy Cities (GRHC) workshop andwith the HRM’s support hosted the eventwith about 45 attendees in April, 2005.

Another champion is Professor JeremyLundholm, of St. Mary’s University, whopresented at the 2005 Green RoofConference. Prof. Lundholm and Mr.Taylor have applied for funding to create aresearch centre to study the ability ofnative Nova Scotia plants to survive onrooftops. Prof. Lundholm proposesreducing the weight of green roofs byreducing the growth medium and usingnative plants. The hope is that reducedweight and cost will provide greateropportunities for existing and newbuildings to include green roofs in theirdesigns or retrofits.

EffectivenessEffectiveness is not measurable at thistime, but Mr. Taylor notes that the BIOEnergy Centre in Halifax is the firstCanadian government building with agreen roof.

Lessons learnedThe green roof movement is just startingin the Halifax area so there are few lessonslearned.

The futureIf the funding for St. Mary’s Universitygreen roof research centre is approved,then within two years research willdetermine if native plants can survive in alightweight medium on a roof. There areabout 12 intensive green roofs in Halifax(the famous Citadel in downtown Halifaxis a green roof ) but as far as is known,there is only one extensive green roof.

Though it has been a slow process to date,Mr. Taylor feels that progress will be madevery quickly when evidence points to thesuccess of using native plants and showsthat green roofs can help meet some of thegoals of the HRM environmental plan.



09-05-06

DescriptionOttawa, the nation's capital, is located at the juncture of the Ottawa and Rideau Riversand the Rideau Canal. With the City of Gatineau in Quebec, it is part of the federalNational Capital Region. Only 9.1 per cent of the city's area is urbanized. The urbanform in Ottawa includes a central developed area, older suburbs, a green belt areaowned by the National Capital Commission (federal government) and four growingsuburban and town centres beyond the green belt. A significant research capacityexists in the capital region, including the National Research Council, which has agreen roof research facility.

The local topography of the area plays an important role. The valley created by theGatineau Hills and the Ottawa River can trap pollutants and create temperatureinversions. Surface winds are frequently less than 0.18 km/h (0.11 mph). Thisexaggerates the urban heat island effect within the City's developed portion.

Key motivatorsOttawa has not identified specific key motivators, but a green roofs workshop inMay, 2004 identified potential benefits, including mitigating the urban heat island,managing stormwater and the amenity value of green spaces in urban areas (promoting“smart growth”). Helping alleviate concerns over the loss of green space, garden plotsor community amenities as a result of infill projects is also a potential motivator.


Case studies

Ottawa, Ontario

Longitude 75º42'W Latitude 45º25'N


19.7°C(67ºF)


-8.5°C (17ºF)


733.2 mm(28.8 in.)


202.7 cm (79.8 in.)

Area2,796 km2

(1,157 sq. mi.)Population 800,000

David MillerSenior Environmental PlannerCity of Ottawa(613) 580-2424, ext. [email protected]

Contact information


Green Roof pol ic ies worldwide—Ottawa, Ontar io

87

In January, 2005, Ottawa City Councilapproved an air quality and climate changemanagement plan that established a targetof 20 per cent reduction in GHG emissionsand cited green buildings and green roofsas one of the implementing mechanisms.

As a newly amalgamated city, Ottawa setout to create a future vision and updatekey strategic documents. Ottawa 2020 wasa two-stage planning initiative that resulted inseven key principles including a green andenvironmentally-sensitive city. As part ofthis process, a new official plan and anenvironmental strategy were passed in 2003.This strategy establishes a firm urbanboundary and is designed to encouragedevelopment within this boundary tomaximize public investments and minimizethe broader environmental impact of growth

Description of the policyThere is no policy to encourage green roofs,though the City's Green Roofs Task Forcehas identified this issue. One developer wassuccessful in having the city waive developmentcharges as recognition, in part, of greenbuilding measures including a green roof.

The city is considering the use of localimprovement charges (LIC). This entails aselection of measures off a prescribed listfor which the city will provide incentivesor assistance for hard costs. This “loan” ispaid back through taxes. Green rooftechnology can be appropriate for thistechnique as the capital costs are associatedwith the building property, rather than thecurrent builder who may sell the propertyupon completion of construction. (Formore information, see “Localimprovement charges” )

The city is also exploring a partnership withNatural Resources Canada to help facilitateprojects under the Commercial BuildingIncentive Program (CBIP). Green roofscould be one acceptable energy-savingmeasure. A community development planfor a new community, Riverside South,encourages green roofs and green buildingin the community core, mixed-use area.Ottawa is now developing an internal citysustainable building policy for greenbuilding construction and for which greenroofs could be a tool.

Process to establish policySeveral groups are pursuing a green roofspolicy, including the Ottawa EnvironmentalAdvisory Committee. This committee ofvolunteers advises Ottawa council on avariety of environmental issues. It encouragesgreen roofs and has participated in theefforts noted below.

The city has also worked with the localchapter of the National Capital GreenBuildings Council (NCGBC), which hasheld sessions on LEED, green buildingsand a Green Roofs Design 101 coursedelivered by Green Roofs for HealthyCities (GRHC).

GRHC first contacted the city about a localgreen roof development workshop in 2003.The GRHC workshop in May, 2004 resultedin the formation of a local Green RoofsTask Force (including the EnvironmentalAdvisory Committee). This task force hasmet twice. Although the task force set manyshort- and long-term goals, policydevelopment being one of them, it has haddifficulty moving forward because of a lackof resources and financial support. Effortsare underway to initiate a green roofinventory once a source of funding is found.

On Aug. 23, 2005, Ottawa City Councildirected staff to develop a green roofstrategy for consideration by Council.


Green Roof pol ic ies worldwide—Ottawa, Ontar io

EffectivenessDespite the absence of formal policy orspecific regulatory requirements, newpublic projects are actively considering andconstructing green roofs. In fact, privatedevelopers appear to be leading. Oneprivate developer, Windmill Developments,asked the city to waive development chargesfor its green building design, which includesa green roof.

Lessons learnedThe province's Planning Act and buildingcode do not lend themselves to a regulatoryapproach and there is no obvious legislationpermitting a municipality to prescribegreen roofs, except on its own buildings.

An integrated approach is critical forencouraging green roof development,especially as part of LEED certification.The city needs the ability to screendevelopment approvals so that green roofscan be promoted during the design stage.

Ottawa benefits from having many federalgovernment departments and agencieslocated in the city. For instance, The newCanadian War Museum has installed agreen roof, part of the sustainable measuresof the federal Greening the Governmentpolicy. Federal greening initiatives providesome opportunities and could positivelyinfluence more local developers' attitudesabout green building construction andgreen roofs.

The futureBoth LEED and the Go Green program ofthe Building Owners and ManagersAssociation (BOMA) of Canada encouragelocal developers to build green for publicimage and marketing benefits. Green roofsfit well with these initiatives. David Miller,an environmental planner with the City ofOttawa, notes that green roofs mustbecome a routine part of a green buildingpackage and be conceived as the right thingto do as part of an integrated design process.



09-05-06

LiteratureOvertveld, J.C. (1990). The Application of “Green Roof” Legislation to the City of Ottawa Official Plan.

DescriptionIn 2008, Québec City, one of the oldest cities in North America, will celebrate its 400th

anniversary. The city is situated on the St. Lawrence River, northeast of Montréal.

Key motivatorsThe green roof movement in Québec City has been gathering momentum, led byVivre en Ville, a non-profit organization that promotes sustainable development.

While Vivre en Ville has identified many key motivators and considered greenroofs for improving biodiversity, it appears that most important motivator isrelated stormwater management.

Description of the policyQuébec City is expected to move into Phase 5 — Program and Policy Developmentthrough its partnership with Vivre en Ville to examine policies for promoting green roofs.


Case studies

Québec City, Québec



18.3°C(65°F)


-15°C (5ºF)


415.6 mm(16.36 in.)

Averageannual snowfall

110.6 cm (43.5 in.)

Area2,796 km2

(1,080 sq. mi.)Population 173,000

Marie Anne BoivinSoprema(450) [email protected]éronique JampierreVivre en [email protected]

Contact information


Green Roof pol ic ies worldwide—Québec City, Québec

Process to establish policyQuébec City can be considered a leader inmodern day green roofs in Canada. In1994, the Horticulture Research Centre ofLaval University started a pioneering researchprogram to adapt European green rooftechnology for extensive and semi-intensivegreen roof systems and rooftop gardens toa Canadian climate. This research projectwas carried out by Marie Anne Boivin underthe direction of Professor Blanche Dansereau.

In November 1994, a green roof wasinstalled on two roofs of different exposuresand levels on the service building of theAgricultural and Food Sciences Faculty ofLaval University. Several green roofs —listed in the following table — have beeninstalled (or planned) since that time inQuébec City.

Québec City has moved successfullythrough the policy development stages andis now in the community engagementphase, the action plan and implementationphase and the technical research phase.

Vivre en Ville is leading the effort througha demonstration project that highlights theuse of plants on building walls and roofs.

In 2002, Vivre en Ville, along with Conseilregional de l’environnement-CapitaleNationale, made a submission to Québec Cityfor a strategy to preserve local biodiversity withgreen roofs as one way to improve biodiversity.

Since then a partnership has evolved, ledby Vivre en Ville, to promote green roofsthrough its demonstration project. Vivreen Ville explored various possibilities forthe demonstration, including workingwith City buildings and those owned by

the municipal housing department. In theend, Vivre en Ville teamed with the Centrefor the Environment and purchased twobuildings, named "Centre Culture etEnvironnement Frédéric Back." Thesebuildings are linked. Their age anddesignation as heritage buildings posed achallenge in determining the type of greenroof that could be installed.

The objectives of the two-phase project are:

Phase 1

� Study the application of green roofsand green walls on two buildings inthe context of northern climate.

� Measure the energy savings

� Measure stormwater retention

Project Built Area — m2 Comments

Pavillon de services, Food andAgriculture Department,Laval University

1994 250 Accessible rooftop garden on flat roof

Pavillon d’accueil,ArboretumDomaine Maizerets

1996 200 Inaccessible roof on 30% slope

Coproprietes Manrèse 1996 215 Garden terrace over garage

Coopérative d’habitation Chloé 1996 80 Garden terrace over wood deckin residential building

Lofts Laliberté 1999 130 Rooftop garden over wood deckin residential lofts

Coproprietes Manrèse III 1999 234 Garden terrace over parking garage

Les Jardins St. Sacrement 1999 100 Rooftop garden terrace in aresidential home for older people

Edifice René-Lévesque 2000 80 Accessible terrace

Centre culture et environnementFrédéric Back

2004 700 Demonstration green roof byVivre en Ville

Charlesbourg Library 2006 3,300 One of the largest accessiblegreen roofs in Canada. It isconnected to adjacent ground



91

� Demonstrate the feasibility andadvantages of the green roofs and wallsto the housing market and to themaintenance and renovation ofinstitutional and public buildings.

Phase 2

� Widely disseminate the results of theproject and attract more partners to the project.

� Demonstrate the need for similarstudies on different types of buildings.

� Demonstrate the community benefits.

Community involvementOne of the major contributions of thisproject towards green roof policy makingand green roof promotion was communityinvolvement. At one level, Vivre en Villewas able to establish funding partners witha vested interest in the outcome of theproject. At another level, it established atechnical and advisory committee.Members of the technical committee are

� Marie-Anne Boivin, green roof specialist

� Gilles d’Amour, Architect with l’Agencede l’efficacité énergétique du Québec

� Jean-Pierre Finet, Manager of Fonds enefficacité énergétique du Québec

� Stéphan Gilbert, Architect with ÉmileGilbert, Brière + architectes

� André Potvin, Architecture Professor atl’Université Laval

� Gabriel Thibault, Sales director withComposts du Québec

� Véronique Jampierre and JérômeVaillancourt, Vivre en Ville.

The project partners are:

� L’Agence de l’efficacité énergétique du Québec (Quebec’s Energy Efficiency Agency)

� Le Centre de l’Environnement (The Environment Centre — a nonprofit organization)

� Le Fonds en efficacité énergétique duQuébec (Quebec Energy Efficiency Fund)

� Le Fonds d’habilitation municipal vert— part of the Federation of CanadianMunicipalities (FCM) Green MunicipalEnabling Fund

� Ville de Québec (Québec CityMunicipal Government) votedunanimously to finance part of theproject and had representation from thedepartment of environment departmentof infrastructure and propertymanagement department.

� Canada Mortgage and Housing Corporation

� Students, academics, consultants,designers, suppliers and contractorscontributed to the project

Funding was procured from the Environment

Canada EcoAction 2000 program.Chantiers-Jeunesse (a non profit organization)participated in the installation.

Lessons learnedThe biggest challenge was to implement agreen roof on an existing building withlimited structural capability. This involvedremoving a roof layer and using a lightweightgreen roofing structure (19 lbs./sq. ft.).Selecting a new roofing system for aninadequate structure has provided usefulinsights, suitable for dissemination.

Research andmeasurement programThe demonstration roof will be monitoredfor thermal and water runoff performance.Temperature measurements of the old roofwere taken before the green roof wasinstalled. Water and temperature readingswill continue for another year.

The amount of water collected by the roofwill be compared with the rainfall collectedat city facilities to show water retention dueto the green roof.

Public awareness anddemonstrationAlready the project has lead to significantpublic awareness of green roofs. Informationtransfer began with project partners andparticipants and included the building’stenants and users. The local chamber ofcommerce organized a meeting to challengeparticipants on the use of green roofs. Pressreleases and bigger events were planned forthe project’s official launch in October, 2005.

The futureThe greening sets the stage for publicawareness and demonstration. There arenow further plans for additional green roofsand walls by the Centre for the Environment.

The Charlesbourg Library will provideQuébec City with one of Canada’s largestpublicly accessible green roofs in 2006.





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Literaturehttp://www.rona.ca/webapp/wcs/stores/servlet/ContentServlet?assetId=7752&langId=-2&parentAssetId=22&parentAssetId=4#93805

Les Toits Verts et ses avantages http://www.rona.ca/webapp/wcs/stores/servlet/ContentServlet?assetId=7972&langId=-2&parentAssetId=22&parentAssetId=4

Vivre en Ville (2004, Novembre) Rapport d’etape du Programme de vegetalisation de batiment, Passons a l’action, projets encours,toitures et murs vegetaux, http://www.vivreenville.org/action_projets.html

Vivre en Ville (2002, Avril) Strategie quebecoise sur la diversite biologique: une avancee pour le maintien de l’integrite biologique du territoire

Vivre en Ville (2005, novembre) Manuel d’installation de toitures et de murs végétaux (en cours de redaction)

DescriptionWinnipeg, on the banks of the Red and Assiniboine Rivers, is surrounded by prairie.Winnipeg is known for its cloudless winter skies and frigid temperatures. Winnipeghas the sunniest winter in Canada, with an average of 99 hours of sunshine inDecember, 120 in January and 140 in February. Summers can be quite hot but short,limiting the growing season. With the consistent cold weather, snow tends to stay forthe entire winter, which offers some protection to plants from freezing temperatures.

There is a wide mix of industry in predominately low, flat buildings in industrialparks, which provides opportunities to retrofit green roofs. There are few tall buildingsin Winnipeg and new construction activity has been slow.

There are several well-known green roofs in Winnipeg. One of the first is the award-winning Ducks Unlimited Oak Hammock Marsh Interpretive Centre, built in 1990.The roof has two tiers, one with shallow-rooted native prairie grasses and the otherwith stress-tolerant Kentucky Bluegrass.

Another well-known Winnipeg green roof is the Mountain Equipment Co-op (MEC)building. This new building used more than 95 per cent reclaimed materials from theoriginal buildings on site. It has been awarded LEED-Gold certification and features agreen roof on a portion of the roof. A cistern in the basement collects rainwater. Thisrainwater is mixed with a small amount of compost tea from the building's compostingtoilets to irrigate the rooftop garden through a solar-powered irrigation system.

Red River College recently completed a downtown campus that includes a small greenroof that students, enrolled in the turf management program will maintain.


Case studies

Winnipeg, Manitoba


Elevation 239m


26.1°C(79ºF)


-23.6 °C (-10ºF)


504 mm(20 in.)

Averageannual snowfall

114.8 cm (45 in.)

Area465.16 km2


Centre for Indigenous EnvironmentalResources (CIER)(204) [email protected] Rodney McDonaldMcDonald & Hardess Sustainability Group Inc. (204) [email protected]

Contact information


Green Roof pol ic ies worldwide—Winnipeg , Manitoba

Key motivatorsStormwater management is the mainidentified motivator: the City hascombined sewer districts and is close totwo rivers. A potential motivator iselectrical energy savings from less use of airconditioning. A third motivator is thebenefit of green roofs as a public amenity,such as community gardening.

Description of the policyWinnipeg has not yet established aprogram, incentive or policy to encouragegreen roof development.

Process to establish policyThe Centre for Indigenous EnvironmentalResources (CIER) became interested inbuilding a green roof on its downtownbuilding. When that wasn't possible, CIERinvestigated funding from the Federationof Canadian Municipalities (FCM) GreenMunicipal Fund to conduct a green rooffeasibility study for the City of Winnipeg.FCM grants require matched funding, soCIER collaborated with the City to meetthat requirement.

In 2003, CIER and TetrES Consultantsresearched the benefits of the green roofsfor stormwater management. Controllingstormwater is a major problem for the city,especially in the Combined Sewer District.From May to October each year, there aretypically 18 stormwater overflows in whichmunicipal storm sewers spill raw sewageinto local waterways. The study showedthat in the combined sewer-stormwaterareas, there is structural capacity tosupport extensive green roofs on most ofthe buildings because they were originally

designed to have upper floors added. Otherpartners in the study included the province ofManitoba (Conservation, and Transportationand Government Services); Syverson MonteyneArchitecture; Altmitra Engineering Ltd.and ATLIS Gematics Inc.

The preliminary study findings show thatgreen roofs can provide important social,engineering and monetary benefits. Inparticular, the study verified that greenroofs in the City of Winnipeg could:

� Enhance stormwater management inthe core area, especially areas withinline storage. (This complementedthe stormwater-management programcurrently planned by the City.)

� Provide cooling benefits for buildings

� Extend the life of a roof

� Trap and treat hazardous air-pollutants

� Sequester carbon where buildingstructures allow for intensive plantings.

Urban heat island effect is not an issue inWinnipeg and was not considered. Thestudy also identified the need for furtherinitiatives by the City of Winnipeg toinvestigate and promote green buildingtechnologies, especially green roofs.

EffectivenessAlthough there has been very little actionby the City of Winnipeg in response to thegreen roof study, it is felt that the reportoverall contributes to the body ofknowledge for the local context. The fullreport is on CIER's website atwww.cier.ca/GRSReport.pdf.

Lessons learnedBarriers that CIER met in the feasibilitystudy included the general lack of awarenessand understanding of what a green roof iscomprised of and its potential benefits, inparticular for stormwater management. Thestudy noted that civil engineers considermore and bigger pipes as the main way todeal with stormwater, not alternativemeasures such as vegetated rooftops that canreduce the need for expensive infrastructure.

Rodney McDonald, formally of CIER, addsthat stormwater has “no public face,” so it isdifficult to engage the public when it can'teasily see and understand the environmentalimpacts of stormwater.


Green Roof pol ic ies worldwide—Winnipeg , Manitoba

95

The futureMr. McDonald hopes that the City ofWinnipeg will eventually encourage andpromote green roofs as a way to deal withstormwater. More research is needed toprove that green roofs can work in Winnipeg'sclimate. More demonstration projects willallow people to experience them from anesthetic perspective and allow the city toverify their benefits in mitigating stormwaterrunoff. The recent MEC project is consideredan inspiration for other green roofs.

The movement towards green buildingconstruction will help, though Winnipeg isnot as active as other areas in new construction.

More research on a holistic perspective —benefits to the building, the city and thecommunity at large — is definitely needed.More research is also required to examine

incentives that the city can offer to developers,builders and building owners. And finally,more research is needed to prove the benefitsand cost-effectiveness for Winnipeg'spredominantly retrofit market. The costsare relatively low for adding a green roof toa new building, but it may be moredifficult and expensive to retrofit a roof.

New developments include the launch ofthe Manitoba Chapter of the Canada GreenBuilding Council and the formation of avolunteer City Civic Environment Committeewith a green building subcommittee. Thiscommittee recently recommended that newrecreational facilities be required to attain aLEED Silver rating. This is the first time aLEED rating has been recommended formunicipal buildings in Manitoba.

Manitoba Hydro's new downtown building(construction started in 2005) will be thelargest LEED building in Canada and oneof the greenest buildings in the world. Thebuilding design includes a green roof.

Mr. McDonald says that the best motivatoris for decision-makers and others is therealization that there is a public cost to aflat, impermeable roof and with managementof the roof's stormwater runoff. If the costof managing stormwater is transferred tobuilding owners, there will then be afinancial incentive for green roofs.



09-05-06

LiteratureCIER and TetrES Consultants Inc. (2003). Development of Green Roof Strategy for the City of Winnipeg, Man. (Report toFederation of Canadian Municipalities). Winnipeg, Man. Retrieved from www.cier.ca/GRSReport.pdf


United States of America

DescriptionThe City of Atlanta is part of Metropolitan Atlanta, which has a population of about3,850,000. Although Metropolitan Atlanta continues to grow and expand faster thanthe City, the City of Atlanta retains its position as the hub of the entire region.

Notable physical characteristics within the city are the rolling, hilly topography,numerous streams and an extensive tree canopy.

At the base of the Blue Ridge Mountains, Atlanta is the meeting point for 10 streamand watershed basins supplying two distinct river basins – the Chattahoochee andOcmulgee Rivers. It is now one of the top five land-consuming metro areas in theU.S. Hurricanes can severely modify the moderate climate and rain can be heavyin major storms.


Case studies

Atlanta, Georgia

Longitude 84°23’W Latitude 33°45’N

Elevation 308 m (1,010 ft.)


26.1°C(79ºF)


7.2°C (45°F)


1,219 mm (48 in.)

Area342 km2


Janet FaustJDR Enterprises Inc.(770) [email protected].

Ben TaubeEnvironmental Manager(404) [email protected]

Contact information


Green Roof pol ic ies worldwide—Atlanta , Georg ia

Key motivatorsThere are three primary motivators for greenroofs in Atlanta. Urban heat island has beenidentified as one. In 1996, a NASA (NationalAeronautics and Space Administration)Science Investigation Project focused on anurban heat island experiment in Atlanta that“sought to observe, measure, model andanalyze how the rapid growth of the Atlantametropolitan areas since the early 1970s hasimpacted the region’s climate and air quality.”NASA thermal infrared photographyshowed that temperature in downtownAtlanta is often 10ºF warmer than thesurrounding areas.

Poor air quality, related to the urban heatisland, is another important issue in Atlanta.The city has a serious ozone problem, andthe 10-degree temperature difference doublesozone production. In October, 2001, NASA,in collaboration with Cool Communities(Georgia), began a federally funded projectto quantify the impact of land cover andland-use changes on air quality, particularlyon ground-level ozone. The results of thisreport were not available in late 2005.

Also related to land-use changes and practices,Atlanta has erosion, sedimentation andstormwater management problems, partlycaused by over-burdened sewer systems.

Atlanta is exploring green roofs as one ofseveral ways to mitigate the effects of higherurban temperatures, degradation of air andwater quality, overflowing sewer systems,and loss of green space.

Description of the policyThe City of Atlanta is promoting greenroofs through a demonstration project.

The City of Atlanta also requires cityprojects to conform to LEED Silverstandards. Green roofs are expected to beconsidered as part of this requirement.

The City is considering an incentive programfor commercial, residential and industrialgreen roof projects. Such incentives maybecome increasingly popular, since the cityis working on creating stormwater feesthat will base fees on impervious surfacecalculations. There are no planned dates forimplementation of these policies and programs.

Process to establish policyIn December, 2003, the City of Atlantainstalled a green roof on its City Hall as ademonstration pilot project, claimed to bethe first such project in the U.S. southeast.The City expected to generate reliabletechnical data for temperature reduction,energy efficiency, stormwater retention,effect on roof life and determination ofwhich plants work best in the shallow soilof a green roof. It also hoped to showAtlanta’s business community a workinggreen roof as a model for similar projects.

Green roofs are expected to help improveAtlanta’s air quality. In Atlanta, air quality,particularly high levels of ground-levelozone, has been designated a “severe” non-attainment area by the U.S. EnvironmentalProtection Agency (EPA). In 2002, the cityexceeded federal ozone standards on 38 days,up from 20 days in 2001. This, along withthe expectation that green roofs will play asignificant role in mitigating stormwaterproblems, led to the demonstration project.

EffectivenessThe green roof pilot project is not movingforward as planned. The green roof is currentlyonly being promoted as one approach tomeet the environmental needs of Atlanta.The roof is not being monitored asexpected and the City ordinance is notnecessarily resulting in green roof activityon City-owned buildings.

Although there are serious stormwaterissues in Atlanta, there are no incentivesfor developers for green roofs. However,the benefits of green roofs as demonstratedby the City Hall project are being noted.Some developers are designing to LEEDstandards and considering green roofs ontheir projects. Southface Energy Institute,a local non-profit organization, is workingwith developers and the community toconsider adopting green roofs as part ofsustainable practices.

Lessons learnedThe Atlanta City Hall demonstration projectrepresented a relatively minor expenditure,primarily because, with outside biddingstarting at $163,000, the city focused onin-house program management, constructionand maintenance. The City received

approximately $55,000 in donated products,a construction grant of $18,000 from theState of Georgia and a matching grant of$18,000 from the city Department ofWatershed Management. The project costa total of $110,000, but after deductingthe donations and grants it cost the Cityonly $19,000. The city parks and recreationdepartment is providing what littlemaintenance the roof is expected to require.


Green Roof pol ic ies worldwide—Atlanta , Georg ia

99

Lack of funds has postponed the monitoringof the green roof. On the other hand,involvement in the project has allowednon-profit groups to educate developers onthe merits of green roofs. This is leading tovoluntary implementation of green roofs onnon-municipal projects.

The futureFor City-owned buildings, green roofs may beconsidered part of the requirement to meetsustainable design standards. It is likely thatAtlanta will move towards a fee for stormwaterbased on the amount of impervious area on abuilding site - probably in 2007. Green roofswould be one measure to decreaseimperviousness when such a new, fee-basedstructure is implemented. In the meantime,the role played by non-profit organizationssuch as Southface will lead to more green roofsbeing considered by private developers



09-05-06

LiteratureCity of Atlanta. (2003). Sustainable Development Design Standards. Retrieved March, 2005, from

Taube, B. & Ward, J. (2004). A Cool Roof in a Hot City: The Southeast’s First Municipal Greenroof. Retrieved in March, 2005, fromhttp://www.greenroofs.com/archives/gf_mar04.htm

DescriptionThe Twin Cities of Minneapolis-St. Paul have a climate similar to Winnipeg’s. Theregion is subject to frequent winds and throughout July and August, hot temperatures,coupled with little to no precipitation, make plant choices for green roofs difficult.

The cities are at the juncture of three major rivers — the Mississippi, Minnesotaand St. Croix. The old cities are on bluffs overlooking the Mississippi.

Each municipality has a separate elected council. Both cities require the approval of ametropolitan council for building development planning. The current mayor ofMinneapolis supports more green roofs. The Green Institute, one of the first greenroofs in Minneapolis, was erected on the Phillips Eco-Enterprise Centre property.

Key motivatorsThe Metropolitan Council approves all new development, waste water treatmentplants, drinking water treatment plants, transportation systems, housing, sewersystems, water resource protection and stormwater management in seven counties.Currently, stormwater quantity and quality concerns the Metropolitan Councilbecause of the number of aging and deteriorating sewers discharging untreated sewage(combined sewer overflow) into the Mississippi River after a rainfall.


Case studies

Minneapolis-St. Paul,Minnesota

Longitude 93º21’W Latitude 44°59’N

Elevation 254 m (833 ft.)


29ºC(85°F)


-32ºC (-25°F)


693 mm(27.3 in.)


91.4 cm (36 in.)

Population 2.5 million

Karen JensenSenior Water ResourcePlanner/Environmental Engineer Metropolitan Council EnvironmentalServices(651) 602-1000 [email protected]

Corrie ZollGreenspace Partners Program DirectorThe Green Institute(612) 278-7100 or (612) [email protected] [email protected]

Contact information


Green Roof pol ic ies worldwide—Minneapol is -St . Paul , Minnesota

101

Fixing this problem would cost about $100 million, which is not available. Thishas spurred the development of alternativestormwater management plans to reducestormwater runoff, improve infiltration andprotect river water sources at less cost. AnUrban Small Sites Best Management Practice(BMP) Manual has been published for usein the Metropolitan region by engineers,architects and other planning professionals.The manual includes detailed informationon 40 best management practices, includinga strong description of green roofs, theirenvironmental benefits, construction details,plant recommendations and more.

Description of the policyThe City reports that the use of bestmanagement plans, such as green roofs, willimprove a building owner or manager’seligibility for a reduced stormwater utilityfee. These monthly fees, established in 2005,are based on a formula that incorporatesroof area, parking lot area and any otherimpervious surface area that generatesstormwater runoff. This stormwater utilityfee is an incentive for building owners toconsider using green roofs and otherstormwater management tools. For moreinformation on this stormwater utility fee, seewww.ci.minneapolis.mn.us/stormwater/

Process to establish policyIn 2003, the Green Institute co-hosted aone-day, green roof market developmentseminar with Green Roofs for Healthy Cities.More than 100 people attended, includingthe mayor of Minneapolis and several citycouncillors. From this seminar, a volunteerTwin Cities Green Roof Council was formedto which architects, engineers, developers

and others interested in market developmentwere invited. A steering committee now meetsmonthly and full meetings are organizedquarterly. Buildings with green roofs arefeatured and highlighted at the quarterly meetings.

In 2004, the Green Institute hosted theGreen Roof Design 101 course presentedby Green Roofs for Healthy Cities.

The Twin Cities Green Roof Council isseeking to develop a thoughtful commentaryon the City’s stormwater utility fee. Thecollected funds are expected to help upgradeurban infrastructure and prevent furthercombined sewer overflows into the river.

The City now separates strategies used bybuilding owners and developers that affectwater runoff quality from those that affectwater runoff quantity. Green roofs are noweligible to provide a credit of up to 100per cent towards reducing a building or aproperty’s stormwater utility fee.

The Green Roof Council is exploring theuse of development bonuses for peopleemploying green strategies (such as a greenroof ) as well as programs or policies thatmake them mandatory for City projects .

Use of best management practices and relatednew technologies, coupled with the effortsof local professionals who are keen to learnmore about green roofs, has had a steadyeffect on raising the profile of green roofsacross the Twin Cities and the Metro region.

EffectivenessThere are about two dozen green roofs inthe Twin Cites with some uniqueofferings, beginning with one built in the1920s. Another provided a lawn bowlingarea. Since 2004, many new condominium

projects have included green roofs as partof their early development plans. CorrieZoll, Green Space Coordinator at TheGreen Institute, suggests that this is due toincreased education and awareness,coupled with the stormwater utility feeand an appreciation for green amenityspace by condo buyers.

Lessons learnedFew green roofs were installed before2003, and they were positioned more asamenities than as strategic environmentaltools to improve air quality and stormwaterrunoff. As such, these older green roofs aredifficult to locate and study. The files outliningdesign factors, themes, costs, materials andplant choices have been difficult to locate.Nonetheless, the Green Roof Council iscataloguing green roofs. Mr. Zoll says thatsince more attention has been given togreen roofs over the past two years therehas been increased interest in them.

Currently, few green roofs monitor stormwaterrunoff parameters, urban heat island andother environmental benefits. However, theGreen Institute is now able to monitor outputsfrom its highly visible green roof, which itwill add to a critical local body of knowledge.The University of Minnesota’s water resourcescentre is working with the School ofArchitecture’s Centre for Sustainable BuildingResearch on this and other projects.

The futureA Metropolitan Council stormwater engineerpredicts that the Twin Cities, along withother U.S. urban areas, will be acutelyinterested in the effect that stringentstormwater management requirements andutility fees will have on business, buildingowners and developers. Already, a number


Green Roof pol ic ies worldwide—Minneapol is -St . Paul , Minnesota

of major American cities are using thesefees to their advantage in terms of supportingstormwater best management practices, waterresearch and new infrastructure planning.Similarly, surface water regulations upheldby the federal National Pollutant DischargeElimination System program, whichformerly applied only to big cities, is nowbeing applied to smaller municipalities.

Green infrastructure, in the form of greenroofs, will help offset the future stormwaterutility fee. This, with increasedunderstanding of the technology, will resultin more green roofs in the Twin Cities area.



09-05-06

LiteratureMetropolitan Council. (2003). Environmental Services. Retrieved from http://www.metrocouncil.org/environment/environment.htm

DescriptionPittsburgh is the largest inland port in the U.S., providing access to the 9,000-mileinland waterway system. Three rivers—the Monogahela, Allegheny and Ohio—convergein the city. Pittsburgh is the major city in Alleghany County, which has a populationof 1.2 million. The three rivers are part of a vast watershed of more than 30,000miles of rivers and streams. The geography is one of plateaus and hillsides alongnarrow valleys and rivers.

Key motivatorsBefore 1972, industry and mining runoff polluted Pittsburgh rivers. The WaterPollution Control Act Amendments brought this situation into the American spotlightand stringent controls on industrial pollution helped reduce effluent discharges.Decades of vigilance and increased public and legislative attention on the WesternPennsylvania watershed have dramatically improved water quality. Dozens ofagencies and organizations have missions that focus on protecting the rivers. Inaddition, most of the polluting heavy industry is gone.


Case studies

Pittsburgh,Pennsylvania


Elevation 350 m (1,148 ft.)


28ºC(82.5°F)


-6º°C (20.8°F)


928.7 mm(36.6 in.)


(43.1 in.)

Population 330,000

Joan BlausteinProject Manager3 Rivers Wet Weather Inc. (412) [email protected] MillerRoofscapes, Inc. (215) [email protected]

Contact information


Green Roof pol ic ies worldwide—Pittsburgh, Pennsy lvania

The 3 Rivers Wet Weather (3RWW) programis a non-profit program that seeks to improvethe quality of Pittsburgh region waterresources by helping communities addressissues such as combined sewer overflows andstormwater runoff. To promote the mostcost-effective, long-term, sustainable solutions,3RWW benchmarks sewer technology,educates the public, funds green roofdemonstration projects and advocates forinter-municipal partnerships that supportstormwater technology. 3RWW receivesfederal funding through the U.S. EPA as wellas private funding for its green roofdemonstration projects. For moreinformation seehttp://www.3riverswetweather.org/f_resources/f_green_roof.stm

There are now about 40 buildings, totallingabout 465,000 m2 (5 million sq. ft.), eithercertified or registered under the U.S. GreenBuilding Council's LEED rating system. TheDavid L. Lawrence Convention Center inPittsburgh claims to be the largest greenbuilding in the world. Pittsburgh's greenbuilding advances have occurred over thelast four years (since the creation of LEED)and it helps support the green roofmovement in the region.

Description of the policyPittsburgh has more than investigated themerits and environmental benefits of greenroofs. The 3RWW program championsgreen roofs and has set the stage for furtherexploration and integration of green roofsin the area. For this reason, Pittsburgh isin Phase 3 — Action Plan Development.

Process to establish policyThe federal Water Resources DevelopmentAct, HR 5428, funds Army Corps ofEngineers-related projects. Recent amendmentsto the Act include water-quality projects,such as sewer construction, streamrestoration and environmental infrastructure.3RWW is working with the PittsburghDistrict of the U.S. Army Corps of Engineersand the regional authority to investigateoptions for reconfiguring the combinedsewer discharges.

Similarly, the 3RWW has been fundedunder the Act to build stormwater bestmanagement practice (BMP) demonstrationprojects that focus on lot-level or low-impactdevelopment (LID) projects. LID wasestablished as a highly effective strategy for controlling urban stormwater runoff in Pittsburgh.

The two primary goals of LID design are to

1. reduce runoff volume throughinfiltration, retention, and evaporation

2. to find beneficial uses for water ratherthan exporting it as a waste productdown storm sewers.

Structural stormwater BMPs fall into threemain categories

1. runoff volume control that isinfiltration-oriented

2. runoff volume control that is non-infiltration oriented (vegetatedroofs and rain barrels)

3. runoff quality control that is non-infiltration oriented.

For the Pittsburgh region, volume controlis the primary consideration, given the ageand deteriorated condition of the sewers,in addition to the soil structure andtopography which limit infiltration.

Therefore, 3RWW demonstration projectsfocus on runoff volume control that is notground-infiltration oriented, such as providedby vegetated or green roofs. The state ofPennsylvania has since created stormwatermanagement guidelines that include greenroofs as a best management tool.

EffectivenessIn November, 2003, 3RWW asked forproposals for green roof demonstrationprojects. By February, 2004, the 3RWWhad received eight proposals totalling $2.6million and had provided about $1million in grant funding.

The following green roof projects havebeen awarded grants :

� Shadyside Giant Eagle (Pittsburgh).Renovation and expansion of an existingcommercial building. Extensive greenroof with five-inch growing mediumusing non-invasive, drought-resistantplants. Excess stormwater will becaptured in cisterns and providegreywater for other uses. 3RWWfunding: $240,000

� Hammerschlag Hall/CMU (CarnegieMellon University) (Pittsburgh).Renovation of an existing building onthe CMU campus. An extensive greenroof will collect discharge from theadjacent main roof area; Pennsylvanianative plants are to be used wherepossible. 3RWW funding: $25,250


Green Roof pol ic ies worldwide—Pittsburgh, Pennsy lvania

105

� Terminal Buildings (Pittsburgh)Retrofit of one section of roof on anexisting industrial building. 3RWWfunding: $55,000

� 213-215 E. Eighth Avenue (Homestead).Renovation of a commercial-residentialbuilding on the main street of Homestead.Extensive green roof for residents of upperfloors. The second side of the attachedbuilding provides a control roof forcompaison. 3RWW funding: $66,000.

In addition, 3RWW is funding thedevelopment of monitoring protocols andprograms that will provide uniformevaluation standards. The engineeringdepartments of the University of Pittsburgh

and Carnegie Mellon University are workingon this monitoring project. The projectidentifies current European and U.S bestpractices for monitoring stormwater quality,retention and diversion on green roofprojects, and for assessing their suitabilityfor use in Pennsylvania. The recommendedpractices will be applied to all green roofprojects in Pittsburgh.

Lessons learnedDevelopers need to be involved from thebeginning as any perceived or actual addedcost to a project can deter a project such asa green roof. Funding for demonstrationprojects has helped promote green roofs.

The futureLocal experts do not predict developmentof a green roof policy in the near future.Pittsburgh is a region with very littlegrowth and a declining population. As longas developers perceive any type of greenrequirements as a risk or a penalty, therewill not be the political will to make greenroofs happen. However, Pittsburgh is aleading city for green buildings and LEED-certified buildings and this initiative mayencourage more green roof installations.



09-05-06

Literature3 Rivers Wet Weather Demonstration Program. (nd). Retrieved from http://www.3riverswetweather.org/

Miller, C. (nd). Roofscapes Inc. – Green Technology for the Urban Environment. Retrieved from http://www.roofmeadow.com/

DescriptionThe Pacific Northwest’s largest city, Seattle lies between Puget Sound and LakeWashington, about 180 km south of the Canada-U.S. border. The City is in ametropolitan population of 3.7 million. The climate is mild, with temperaturesmoderated by the sea and the Olympic mountains protecting the city from windsand storms. The "Rainy City," as it is known locally, receives less precipitation ayear than most major Eastern Seaboard cities. However, Seattle is cloudy an average of226 days a year, compared to 132 for New York City. Because Seattle is in the rainshadow of the Olympic mountains, most of the precipitation falls as drizzle orlight rain. The temperature and weather are similar to that of Vancouver, B.C.

Key motivatorsWashington was the first U.S. state to require new publicly funded buildings largerthan 465 m2 (5,000 sq. ft.) to meet LEED Silver certification. The law, passed inApril 2005, is expected to affect billions of dollars of construction projects over thenext few years. High-performance green building with green roofs will be eligiblefor a reduction in stormwater utility fees, which seek to protect local rivers and theocean from polluted stormwater runoff. Protection of waterways, coupled withcore urban values for “green” and sustainable development, drive green roofdevelopment in Seattle.


Case studies

Seattle, Washington




28°C(82.5°F)


-6°C (20.8°F))

Averagerainfall

890-970 mm (35-38 in.)

Population 569,101

Lucia AthensChair of the City of Seattle Green Building Team, LEED Accredited(206) [email protected]

Patrick CareyHadj DesignDirector, Ecobuilding Guild(206) [email protected]

Miranda MaupinSeattle Public [email protected]

Contact information


Green Roof pol ic ies worldwide—Seatt le , Washington

107

Description of policyNo green roof policy as yet.

Process to establish policyWhile there is no direct policy supportinggreen roofs in Seattle, green roofs receivesupport indirectly though Seattle’s “CitySustainability Building Policy.” Thisinitiative, coupled with the now mandatorysupport for LEED-certified buildings, isbringing green roofs into the design andplanning stages for building professionals.While each building requires a separateassessment for earned credits, green roofscan contribute up to 11 credits towardLEED certification in some cases. Moreexperience with green roofs may changethese credits toward LEED certification

The City supports green roofs in theprivate sector through the NorthwestEcobuilding Guild Project. A directorfrom the guild, Patrick Carey of HadjDesign, is both designing and installinggreen roofs on commercial and residentialbuildings and reports that 30 green roofshave been installed since August, 2004.

Similarly, the city’s Flow ControlRequirements Manual for stormwatermanagement currently provides for areduction credit in the impervious surfacefee for building owners with a green roof.

The Seattle Office of Sustainability andthe Environment recently received a grantto encourage green roofs in new andretrofitted buildings and is consideringawarding funds to several green roofprojects in Seattle. Seattle Public Utilities(the city’s water, drainage and solid wasteutility) is examining a variety of drainagestrategies that could be encouragedthrough changes to regulations, cashrebates or revised utility fee rates. Overall,green roofs appear to be a mainstay of thegreen building movement in Seattle.

Effectiveness In February, 2005, Seattle celebrated thefifth year of its landmark policy requiringa LEED Silver rating on city-fundedbuildings. In April, 2005 King CountyCouncil (home of Seattle) unanimouslyadopted an ordinance that requires futurecounty projects to seek the highest LEEDcertification possible on new buildingprojects. This green construction lawreceived strong support among councillors,despite opposition from developers fearinghigher upfront financial costs. State wide,90 green public and private buildingprojects are in the works, 16 of which havealready received LEED certification.

In the Seattle area, the law and policysupporting LEED certification has sparkedinterest for 32 city-owned projects that mustaim for some level of green certification.Seattle’s City Hall and Justice Center aretwo buildings in the city with green roofs.Other buildings in Seattle with green roofprojects include the Ballard Library, aParks project and the Pint Defiance Zoo.

Lessons learnedAccording to Lucia Athens, chair of theCity of Seattle Green Building Team of theSeattle Public Utilities Sustainable BuildingProgram, one of the challenges has beenobtaining solid and reliable green roofperformance data for Seattle. Several recentprojects underway include monitoring ofgreen roofs by the Northwest EcobuildingGuild and by Magnusson KlemencicEngineers, to add more geographic- andcity-specific data. Patrick Carey reports that apartnership with Evergreen State College,Pommegranate Centre and Seattle PublicUtilities to institute more green roofmonitoring sites (10 test panels on 10 greenroofs) will support the need for more localdata. With more Seattle-based performancedata, Ms. Athens suggests that a strongerbusiness case can be made for includinggreen roofs in green building initiatives.


Green Roof pol ic ies worldwide—Seatt le , Washington

The futurePolicy makers in the Seattle area seemconvinced that the higher upfront costs ofgoing green (be it green roofs or greenbuildings) will balance out in the long run— thanks to lower stormwater and energybills and maintenance costs. Seattle mayalso regulate measures to improve indoor airquality and improve health of employees.

Seattle developer Gregory Broderick Smith,among other architects and real estatedevelopers, traveled to Sweden in 2004 totour the Green Roof Institute and theAugustenborg Botanical Roof Gardens inMalmo. Mr. Smith now predicts that whileit’s going to take a while for the private

sector to embrace green construction, itwill happen. Mr. Smith is aiming for LEEDGold on his latest project — the RedoBuilding in Pioneer Square. This officebuilding will feature a green roof, solarpanels, operable windows, exposed timbersand perhaps a small rooftop wind turbine.

“After having viewed the eco-roofsin person, I am convinced it is the roof ofthe future. It is attractive, long-lasting,cost-effective and over the long term itis both socially and environmentally thecorrect application. I plan to installthem in my properties.”

Gregory Broderick Smith

Public schools in Seattle are relative newcomersto green building construction — but areexpected to be a major force for greenroofs. The state is planning to partner withlocal school districts and build, on average,more than 140,000 m2 (1.5 million sq. ft.)of school space every year for the next fewyears, and some will have green roofs.

Others predict that the next frontier isresidential development in Seattle wheresingle-family homes will feature green roofs,rain barrels and more. Hadj Design in Seattleis providing seminars for do-it-yourselfersso owners can install green roofs themselves.



09-05-06

LiteratureCity of Seattle. (2000). Sustainable Building. Retrieved from http://www.cityofseattle.net/sustainablebuilding/

DescriptionWashington, D.C., is a federal district with a population of 560,000. The WashingtonMetropolitan Region, with a population of 5,090,000, contains 24 counties in thesurrounding states of Maryland, Virginia and West Virginia and has an area of17,920 sq km (6,920 sq mi).

The City is located at the confluence of the Potomac and Anacostia Rivers and isflanked by the states of Maryland and Virginia. Washington’s climate is hot andhumid in the summer and cool and damp in the winter.

Separate stormwater sewer systems serve about two-thirds of the District and a combinedsewer system serves the remaining third, or about 5,115 ha (12, 640 acres) — areasprimarily developed before 1900.


Case studies

Washington D.C andChesapeake Bay Area




25°C(77°F)


2.7°C (37°F)

Averagerainfall

1,034.4 mm(40.7 in.)

Average snowfall

42.16 cm (16.6 in.)

Area

17,920 km2

(6,920 sq mi)(Metropolitan area)

Population 560,000

Jessica BlackburnAlliance for the Chesapeake Bay(804) [email protected]

Dawn GiffordD.C. Greenworks(202) [email protected]

Contact information


Green Roof pol ic ies worldwide—Washington D.C and Chesapeake Bay Area

Key motivatorsOver the past 30 years Washington D.C.has lost 64 per cent of its heavy tree coverand its stormwater runoff has increased by34 per cent.

The Anacostia, Potomac and Rock CreekRivers within the District of Columbia donot meet federal water quality standards.To meet the standards, the District isinvesting $1.9 billion in a long-termcontrol plan to manage combined seweroverflows by building three undergroundstormwater tunnels.

Similarly, D.C. is not meeting federal airquality standards for ground level ozone andparticulate matter. This alone jeopardizesabout $120 million of annual federalhighway funding to D.C. The Districtreports the highest asthma rate in theUnited States, at 6.5 per cent for childrenand five per cent for adults.

The key motivators for green roofdevelopment include reducing combinedsewer overflow events and the need toimprove air quality and, by extension, thehealth and quality of life of its citizens.

Description of policyCurrent incentives that support greenroofs in Washington, D.C. include anexpedited review and permit process forgreen roofs, increased floor-area ratios(FAR), tax benefits (reduced propertytaxes) and stormwater management plancredits for green roofs.

Process to establish policySeveral projects that support green roofinfrastructure development include CaseyTrees Endowment Fund with Limno-Tech,Inc.; D.C. Water and Sewer Authority;Chesapeake Bay Small Watershed GrantsProgram; National Fish and WildlifeFoundation, The District of ColumbiaHealth and Watershed ProtectionDivision; and, the U. S. EnvironmentalProtection Agency.

History of funding forgreen roofs in D.C.In 2003, the U.S. Department of Justice,the EPA and a coalition of citizen groupsreached a partial settlement under theClean Water Act in litigation against theWashington D.C. Water and SewerAuthority (WASA). Their effort launchedan extensive program to reduce illegaldischarges of untreated sewage into theAnacostia and Potomac Rivers and RockCreek. The settlement required WASA topay a $250,000 penalty for past violationsand undertake or fund $2 million instormwater pollution prevention. Of the$2 million, $300,000 was to be placed in afund for the development of roof gardens.The interim measures to be taken by WASAinclude steps to limit combined seweroverflows. This may also result in thepromotion of green roofs as a strategy forsource control.

Chesapeake BayFoundationIn 2005, the Chesapeake Bay Foundation(CBF) gave $200,000 in grants to threecorporations: JBG Companies., AkridgeReal Estate Services and Anacostia EconomicDevelopment to create environmentallysensitive, landscaped roofs on office buildings.

Half of the grant money was designated.for a 6,317 m2 (68,000 sq. ft.) vegetatedroof at the new headquarters for the U.S.Department of Transportation along theAnacostia River.The rest will be used toinstall a 929 m2 (10,000 sq. ft.) roof indowntown D.C. and in historic Anacostia.

D. C. GreenworksD.C. Greenworks is a non profitorganization that provides assistance inimplementing low impact development (LID)technologies. The LID program helpsowners of commercial, multi-residential orsingle-family residential property in theD.C. area to install green roofs, rain gardensor rain barrel systems to save energy, cutmaintenance costs and improve the qualityof life.

In the state of Virginia, a grant competition ispromoting green roofs by awarding agrant of $28,000 for a green roof on anon-residential project. The Alliance for Chesapeake Bay is promoting the grant competition.


Green Roof pol ic ies worldwide—Washington D.C and Chesapeake Bay Area

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09-05-06

LiteratureAlliance for the Chesapeake Bay. (2004). Want to Replace your Roof? Save Some Green and Make it Green!. Retrieved April 2005, fromhttp://www.alliancechesbay.org/pressrelease.cfm?id=195

Alliance for the Chesapeake Bay. (2004). Green roof promotional contest for Central Virginia. Retrieved April 2005, fromhttp://www.acb-online.org/pubs/projects/deliverables-240-2-2004.PDF.

D. C. Greenworks. (nd). Current and Completed Projects. Retrieved April 2005, fromhttp://www.D.C.greenworks.org/LID/LIDprojects.html

Van Zee, J. (2004, September). An international cross-cultural exchange 1999 to 2004 (43-46). Presented at the International GreenRoof Congress, Nurtingen, Germany.

EffectivenessThe Mayor of Washington D.C., AnthonyA. Williams, referenced the Vision for aComprehensive Plan for Washington, D.C,in his remarks at the 3rd annual GreeningRooftops for Sustainable Cities Conferencein May, 2005. This plan includes anenvironmental agenda, a desire to clean upthe local rivers such as the AnacostiaWaterfront Initiative and the long-termcontrol plan for stormwater improvements.

In 2004, there was less than 929 m2

(10,000 sq. ft.) of green roof coverage inD.C. More than 18,581 m2 (200,000 sq. ft.)is planned for 2005–2006. Most of thesegreen roofs are being supported by fundingfor a portion of the incremental costs of thegreen over a conventional roof. The CaseyTrees Endowment Fund proposes continuedgrant funding programs and other incentivesfor re-greening Washington D.C. TheFund’s vision includes a “20:20:20 vision”

— where in 20 years, 20 per cent of theroofs in Washington will be greened,representing 20 million square feet (1.8 million m2)of green roof coverage.

The District government is showingleadership by directing that all new Districtgovernment buildings be LEED Silvercertified or the equivalent.

Lessons learnedAccording to a 2003 report by the U.S.Department of Energy, Energy Efficiencyand Renewable Energy Network, Centerfor Sustainable Development, buildings inWashington D.C consume:

� 12 per cent of D.C.'s consumption offresh water

� 35 per cent of total energy use

� 40 per cent of raw materials

� 65 per cent of electricity use

� 88 per cent of potable water supplies

and generate 30 per cent of the District’sgreenhouse gas emissions

Strategies to reduce these figures throughthe installation of green roofs will be apositive step.

The futureAdvocates of green roofs suggest that hydrologicmodelling of stormwater reduction, waterquality benefits, heat-island modelling andenergy savings for Washington D.C. willfurther improve the general understandingof the environmental benefits. The visionfor greening D.C. includes green roofs as onestrategy among many to improve stormwaterrunoff quality and improve air quality.There is optimism among green roofadvocates that green roofs will find theirway into the planning documents proposedfor the many new buildings predicted forWashington D.C in the next decade.


International

DescriptionBerlin is the federal capital of the reunited Germany. Berlin is one of three Germancity-states, combining the functions of city and state, with a senate having theexecutive function.

Fresh new approaches to urban design have been and continue to be applied in Berlinfor relatively large and important projects. The unique opportunity to develop the vastcentral area after reunification provided a testing ground for innovative, large-scale projects.The oasis of green urban planning is largely a result of the Landscape Program for Berlin1984–1994 with its four master plans (for the protection of nature and wildlife, naturalresources, landscape, and recreation areas). They defined the high value placed on nature.

Key motivatorsBerlin has been concerned with the increasing effects of urbanization, such as alack of green space and stormwater management, since the 1970s. Denselydeveloped land is severely limited in its function by:

� a high degree of impermeable ground cover

� inadequate replenishment of groundwater resulting from rapid runoff ofrainfall into the sewage system

� lack of humidity and excess warming of air

� a constant decrease in plant and animal habitat due to inadequate green space.


Case studies

Berlin, Germany1

Longitude 13º25’E Latitude 52º30’N



25°C(77ºF)


-2°C (28ºF)

Population 3.4 million

1 Used with permission from “Tools for Encouraging Sustainable Design” (2004) by Goya Ngan. Minormodifications from the original document have been made. The document can be found online at www.gnla.ca.


Green Roof pol ic ies worldwide—Berl in , Germany

Description of the policyBerlin established a Biotope Area Factor (BAFor BFF for BiotopFlächenFaktor) in the 1980sin the western sector before reunification.It resembles other urban planning instrumentssuch as floor space ratio. The BAF contributesto standardizing the followingenvironmental goals:

� safeguarding and improving themicroclimate and atmospheric hygiene

� safeguarding and developing soilfunction and water balance

� creating and enhancing the quality ofthe plant and animal habitat especiallywild species

� improving the residential environment.

The BAF is required in areas with a legallybinding landscape plan. There are about 13such areas in Berlin. Outside these areas,the BAF is voluntary and can be used as aguideline for environmental measureswhen changes to the existing buildingstructures are proposed.

Calculating the BAFThe BAF expresses the ratio between theecologically effective surface area and thetotal land area.

For each type of urban form, planners seta particular BAF target value. For example,new residential structures have a BAF targetof 0.60 and new commercial structureshave a BAF target of 0.30. For renovations,the BAF target may fluctuate depending onthe existing degree of coverage. For instance,a residential renovation with a degree ofcoverage of more than 0.50 has a BAFtarget of 0.30.

Each type of surface on the proposed planis measured and assigned a measure ofrelative importance according to itsecological value (see following table).

Weighting factor per m2 of surface type

Description of surface type

Sealed surfaces—0.0 Surface is impermeable to air and water and has no plant growth.(that is, concrete, asphalt, slabs with a solid sub-base)

Partially sealed surfaces—0.3 Surface is permeable to water and air; as a rule, no plant growth (that is, clinker brick, mosaic paving, slabs with a sand or gravel sub-base)

Semi-open surfaces—0.5 Surface is permeable to water and air; infiltration; plant growth (that is, gravel with grass coverage, woodblock paving, honeycomb brick with grass)

Surface with vegetation,unconnected to soil below—0.5

Surfaces with vegetation on cellar covers or underground garages with less than 80 cm (31.5 in.) of soil covering

Surfaces with vegetation,unconnected to soil below—0.7

Surfaces with vegetation that have no connection to soil below but with more than 80 cm (31.5 in.) of soil covering

Surfaces with vegetation,connected to soil below—1.0

Vegetation connected to soil below, available for development of flora and fauna

Rainwater infiltration per m2 of roof area—0.2

Rainwater infiltration for replenishment of groundwater; infiltration over surfaces with existing vegetation

Vertical greenery up to a maximum of 10 m (32.8 ft.)—0.5

Greenery covering walls and outer walls with no windows; the actual height, up to 10 m (32.8 ft.), is taken into account

Greenery on rooftop—0.7 Extensive and intensive coverage of rooftop with greenery

Berlin’s (BAF) Biotope Area Factor

BAF=ecological ly ef fect ive surface/total land


Green Roof pol ic ies worldwide—Berl in , Germany

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Process to establish policyBerlin has a long history of green roof policy.In the 1970s, researchers from the TechnicalUniversity of Berlin began examining theecology of the city’s green roofs. At thesame time citizens began pressing for thesupport of more environmentally friendlycities. Many projects were implemented,driven by the environmental movement.

Between 1983 and 1996, a Courtyard GreeningProgram aimed at adding green space in theform of green roofs, green facades andbackyard community gardens to the mostdensely sealed areas of the city. Throughthe program approximately 65,750 m2

(707,727 sq. ft.) of extensive green roofswere subsidized. The program reimbursedresidents for about half of their installationexpenses. Berlin has since had deficits andno longer offers direct financial incentives.

Berlin also has a stormwater fee, administeredby the Berlin Water Corporation, acorporation 50.1 per cent publicly owned.The stormwater fee for 2004 is 1.407 €/m2/yr,based on impervious surfaces. Green roofsdo not earn a discount. However, if therunoff is not connected to the drain, theroof area is not counted. Green roofs aresometimes integrated into local land-useplans, either as source-control measures oras nature-compensation measures. This isadministered by the boroughs.

EffectivenessThe goals of this policy are numerous andaimed at improving the general quality ofthe urban landscape. There are so manyfactors involved that accurately quantifyingall the benefits is not possible.

City planners have received positive feedbackfrom architects and property owners wholike the BAF because it is easy to use andthere are immediate visual improvements aswell as energy savings. In addition, it leavesdesigners and property owners with roomfor individuality, creativity and flexibility.City planners appreciate that it follows thesame logic as other planning indices andratios. The BAF also works well in existingneighbourhoods where there is a lack ofgreen space.

Lessons learnedThere are no specific design requirementsor performance goals for green roofs. Theymust simply conform to industry standards.That said, technical issues are extremelyimportant. In the early days, when standardswere not well developed and workers lackedknowledge and experience, there wereproblems, such as erosion of substrates,leaks in the waterproofing and inadequatemaintenance, which resulted in the growthof unwanted plant species whose rootssometimes damaged the waterproofing.

Training city staff for the BAF is fairlystraightforward because of the BAF’s similarityto other German planning instruments.However, a shortage of staff has made itdifficult to check for compliance. Severalyears may pass before a green roof is inspected.

DescriptionThe overall climate in England is temperate maritime — mostly mild. It is alsodamp and subject to frequent changes in weather. The Atlantic Ocean, and thewarming of its local waters by the Gulf Stream provide a temperate climate.

Key motivatorsA key motivator is the protection of the black redstart (Phoenicurus ochruros), anendangered bird that breeds and nests in urban brownfield sites in the Greater

London Area.

In London, the Mayor's Biodiversity Strategy supports green roofs, saying that “byproviding suitable substrates on roofs will allow wasteland flora and fauna to colonizenaturally.” It also mentions the physical and psychological benefits that are afforded toLondon's residents by greater contact with green spaces.

In addition, the Mayor's Biodiversity Strategy reinforces the Urban Taskforce's findingson the benefits of green spaces. The greatest endorsement of green roofs specificallycomes under the heading of “wasteland biodiversity.” This policy document says

“where wasteland habitats are lost to development it is important that mitigation and compensation should concentrate on provision of similar habitats…such as creating wasteland habitats on roofs”.


Case studies

London,United Kingdom




15.5°C(60°F)


4.4°C (40°F)


754.3 mm (29.7 in.)

Area1,580 km2

(620 sq. mi.)Population 6,767,500

Mathew FrithPeabody Trust [email protected].

Dusty GedgeGreen Roof Consultant [email protected]://www.livingroofs.org

Contact information


Green Roof pol ic ies worldwide—London, United Kingdom

117

Description of the policyThere are now no planning or building codesto encourage the design and implementationof green roofs in Britain. National planningpolicy neither directly refers to green roofsnor implicitly includes them. There are nogovernment incentives or support for greenroofs. The first Urban White Paper in theU.K. in over 20 years — a report that callsfor the renaissance of urban design qualityand deeper community capacity-building— does not mention green roofs.

Process to establish policyCurrent planning legislation allows localauthorities in the Greater London Area toprepare supplementary planning guidance(SPG) on matters of relevance to theirlocation. Some authorities are using theSPG to improve thermal efficiency, energyand water use, drainage and constructionmaterials. London's Westminster City's SPG(2003) makes reference to green roofs.Similarly, Lewisham Council's revised unitarydevelopment plan (2002) contains a specificgreen roof policy. The most support for greenroofs goes to references in the British Councilfor Offices' (Corporation of London) researchadvice note on green roofs (2003), whichhas been taken very seriously by planningand related professionals.

The government's £22 billion SustainableCommunities program, launched inFebruary 2003, sets out a program of actionto address a range of fundamentalinfrastructure issues within the context ofthe shortage of housing across the U.K. Ademand for 4.4 million new homes ispredicted by 2021. Green roofs are appearingas just one of a fairly complex recipe ofsustainability features to meet increasingly

rigorous environmental impact criteria;however, Mathew Frith, landscape regenerationmanager of the Peabody Trust, warns thatwith complexity comes confusion amongdevelopers and clients about the importanceof green roofs. Mr. Frith notes that whilethere are no policies in support of greenroofs, there are none that detract fromgreen roofs either.

Optimism for green roofs now springs fromthe role of London's Mayor, Ken Livingstone,who heads the Greater London Authority(GLA). His duties and powers include thepreparation of strategies for London toexpress economic development, biodiversity,energy savings and many others while inkeeping with the principles of health,equalities and sustainable development.According to Mr. Frith, the Mayor holds aunique position to help green roofs gomainstream. The GLA is the strategicplanning authority for London and haspublished the London Plan. Surroundingboroughs' plans must be in keeping withthe London plan such that

“Wherever appropriate, newdevelopment should include new orenhanced habitat, or design (e.g.green roofs) and landscaping thatpromote biodiversity and provisionfor their management.”

EffectivenessAccording to Livingroofs.org, green roofshave been appearing more frequentlythroughout the U.K. since 2003.Livingroofs.org is a non-profit organizationestablished to promote, advise upon andseek research into green roofs and similarstructures within the context of urban andrural regeneration. It does not providegreen roof products but provides:

� Professional, independent advice ongreen roofs through its contacts withconsultants and the green roof industry.

� Independent consultants for specificprojects/themes.

� Strategic reports on how green roofs canplay a real role in terms of sustainabilityin urban regeneration areas, local andregional authority plans, etc.

� An online resource for researchers,planners, developers, regenerationprofessionals, ecologists, engineers and others.

� An online resource of current and pastresearch documentation on green roofs.

� A portfolio of successful green roof

projects, with information on theircost and construction.

� Signposts to key green roof systemmanufacturers, products and greenroof resources.

� Tours of green roofs in London (inparticular the Canary Wharf area) forinterested parties.

� Speakers at conferences and eventsregarding green roofs and similarfeatures in terms of urban regenerationand sustainability.



According to Mr. Frith, much of the greenroof activity in the U.K. has been in thecommercial sector where the focus is onprotecting brownfield biodiversity in innerurban areas. This is the protected breedingand nesting ground of the black redstart.

The largest green roof in the U.K. —40,000m2 (430,556 sq. ft.) was recentlyinstalled on the new Rolls Royce factory inChichester, West Sussex. (Rolls Royce isowned by BMW in Germany, where BMWsites have green roofs.) In the West Midlands,the Walsall Bus Garage, WolverhamptonUniversity and Birmingham Hospital havegreen roofs. The new Fort Dunlop developmentin Birmingham includes a green roof in thedevelopment plan, in part because of concernsabout conservation of the black redstart.

Over the last 40 years, many well-knowncitizens in the U.K. have included green roofson their homes. Some recent housingdevelopments include green roofs in theirplanning. Other housing authorities andco-operatives have also installed green roofs,including Acton Housing Association, Co-Housing Limited, East ThamesHousing Association, Hedgehog Self-BuildCo-Op, Hockerton Housing, Notting HillHousing Group and Peabody Trust.

The government's Housing Corporation,(the agency regulating U.K. housingassociations) has published a sustainabilitystrategy and established an innovation andgood practice grant fund. This strategy commitsthe housing sector to raise its environmentalstandards in new developments and to scorecredits on a rating system called Eco-Homes.Eco-homes is the housing version of BREEAM(Building Research EstablishmentEnvironmental Assessment Method) whichis similar to LEED in North America. Creditson the Eco-Homes rating scale are granted

for sustainable inclusions, such as reducedenergy and water use and ecology. Verylittle work has been done on the inclusionof green roofs for Eco-Home credits. Somesuggest that credits may be lost for a greenroof as it adds more materials inconstruction. Thus far, BREEAM has notbeen a likely incentive for green roofs.

A unique green living developments in the U.K.is the BedZED (Beddington Zero-EmissionDevelopment) in the London Borough ofSutton. The 82 home and work units aredesigned to be highly energy-efficient andeco-friendly. The units are capped with acurved green roof of sedum mats to reducesurface water runoff and provide greenspace for residents. The green roof hasbecome very popular with the residents.

Lessons learnedAside from the capital costs, there are a numberof perceived problems regarding green roofinstallation. A study in London in 2002identified a number of these perceived problemsby interviewing a number of professionals(architects, engineers, landscape architects)and interested parties. The London studyasked participants to agree with thestatement: “the physical structure of themany buildings prevents the establishmentof green roofs.” These were the responses:

Another perceived barrier illuminated bythe survey was that the costs associated withmaintaining a green roof are prohibitive. Inthe U.K., green roofs are expected to addabout £1 per square metre per year to theoperating costs of the building. The studyindicated that many design professionals arekeen to see more green roofs in the U.K.,however many cited the lack of technicalguidance, education and governmentsupport as a barrier.

Livingroofs.org responds to this survey bynetworking with political decision makers,providing technical advice, supporting researchin the development of technical standardsand certification, attending conferences andproviding tours and seminars about localgreen roofs.

The futureCurrently, enthusiasm for green roofs is limitedto a few design companies, some professionalsand other related enthusiasts. According toFrith, the installation of green roofs on housingprojects, as of late, has been dismissed as thework of “hair-shirted hippies.” However, thework at BedZED project, among others, issetting a new standard and turning someheads in the U.K.

Similarly, good work has leveraged the researchand implementation successes shown in Basel,Switzerland; Malmo, Sweden; and Germany.Still however, the understanding andimportance of green roofs is limited toindividual companies and a few enthusiasts.The creation of a website, www.livingroofs.orghas focused on the policy deficits in the U.K.The organization is also working on thedevelopment of British design standards.The British at present rely upon GermanFLL Standards to guide green roofinstallation. However, only manufacturers

Occupation % Agreed

Environmentalists 67

Architects 40

Planners 33

Engineers 27

Developers 92

Ecologists 13

Other 50



119

are monitoring the green roofs. While thedesire for green roofs is predicted to growexponentially over the next few years, thereis a need for minimum industry standardsand certification.

In June 2005, some manufacturers, theGLA, Livingroofs.org and other interestedparties met at the British Standards Institute tostart work on establishing codes of practiceand standards for green roofs.

The Construction Industry Research andInformation Association is working onBuildings and Biodiversity, a guide thatincludes a significant section on green roofs.This book will published in 2006 and willbe the first major industry guide in the U.K.



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LiteratureDunnet, N. & Kingsbury, N. (2004). Planning Green Roofs and Living Walls (254).Portland, Oregon: Timber Press.

English Nature Report. (2001). Green roofs: their existing status and potential forconserving biodiversity in urban areas. Retrieved from www.blackredstart.org.uk

Gedge, D. (2003, May). From Rubble to Redstarts…Black Redstart Action Plan WorkingGroup. Presented at the Greening Rooftops for Sustainable Communities Conference,Chicago, Illinois.

Livingroofs.org. (2003). Green Roofs Benefits and Cost Implications - A report forGroundwork Birmingham Sustainable Eastside.

DescriptionThe state of North-Rhine Westphalia (NRW) is a highly industrialized region. Ithas more than 18 million inhabitants, making it Germany’s most heavily populatedstate. The state contains the heavily industrialized Ruhr River region, and includesthe cities of Essen, Dortmund, Duisburg and Bochum, Düsseldorf, Cologne and Bonn.

While it once depended heavily on the coal and steel industries, today 66 per cent ofthe NRW workforce is employed in the service sector. Many energy producers andsuppliers have their headquarters in NRW; it is also a prime location for the large-scalepower plant industry and the chemical industry. The state also hosts many innovativefirms active in environmental protection, making it one of Europe’s foremost centresof environmental technology.

Key motivatorsWith two major rivers and ample rainfall, stormwater management and improvingwater quality are the key motivators for green roof policies. Source controls can reduceand delay stormwater runoff. This in turn reduces sewer overflows, reduces the load atwater treatment plants, reduces flooding and allows certain areas to be disconnectedfrom the sewer system.

Description of policyLaunched in 1996 the Ecological and Sustainable Water Management Initiative isthe first state-level subsidy program for green roofs in Germany. The €20 millionprogram was developed by the NRW Ministry of Environment, Consumer Protection,Nature Conservation and Agriculture (MUNLV). The program applies to a varietyof stormwater management initiatives. Funding is derived from waste water fees setby the Wastewater Charges Act. The fees must be used to improve water quality.

Municipalities in the NRW administer the program through their engineering, tax, orenvironmental departments (see Münster, Section XX.) Typically, the municipalitieshave a qualified representative on staff and have information on their websites.


Case studies

North-Rhine Westphalia, Germany

Christof Mainz

Ministry of Environment, ConsumerProtection, Nature Conservation andAgriculture

[email protected]

Contact information


Green Roof pol ic ies worldwide—North-Rhine Westphal ia ,Germany

121

SubsidyThe program subsidized four types ofstormwater management:

1. Removal of impervious surfaces:€15/m2 of removed surface

2. Infiltration systems: €15/m2 of infiltration surface

3. Green roofs: €15/m2

4. Systems that re-use rainwater: up to€1,500 per system

The program applies to existing urban areas.New developments are usually required toimplement some form of stormwater controland are therefore not eligible for the subsidy.Initiatives that are required as an ecologicalcompensation measure also do not qualify.The subsidy may be used with thestormwater fee discounts.

Green roofsSubsidies for green roofs are available for bothnew and retrofitted buildings. The greenroof must have a runoff coefficient of 0.3 orless, meaning that it must retain about 70 per cent of stormwater. This level canbe attained by installing an extensive greenroof with a growing medium depth of 10 to15 cm (4 to 6 in.). Furthermore, the greenroof must be at least 34 m2 (366 sq. ft.).Some municipalities have their ownincentive programs for smaller green roofs,which are typically installed on carports.

To apply for the subsidy an applicationmust be submitted containing the size ofthe proposed green roof, the depth of thecomponents, the portion affected bystormwater delay, the runoff coefficientand whether the load-bearing capacity hasbeen approved.

Process to establish policyThe incentive program was developed byMUNLV in 1995 after the Green Partytook office.

Effectiveness From 1996 to 2004, the program paid€16,551,595 on green roof subsidies to4,138 applicants. When the removal ofimpervious surfaces and the installation ofstormwater source controls are added tothese numbers, total expenditure by theMUNLV equals €75 million. This hasresulted in approximately 6 million m2 (65million sq. ft.) of surface area that couldbe disconnected from the sewer system.

Lessons learnedThe financial incentive was key in

motivating home and property owners toimplement stormwater source-controlmeasures. The incentive also led to arethinking of how to design and buildgreen roofs and homes.

The incentive played an important role instimulating the green roof market, withsmall-and medium-sized businesses profitingthe most. These businesses were also encouragedto seek out and develop new technologiesto meet the increasing demand.

The futureThere was a change of government in May2005, which has left the future of theprogram unknown.

LiteratureMUNLV. (2005). Antwort: Nachhaltigund ökologische Wasserwirtschaft ausMitteln der

Abwasserabgabe. Nordrhein-Westfalen



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ResourcesBooks–Publications

Title Planting Green Roofs and Living Walls

Authors Nigel Dunnet and Noel Kingsbury

Publisher Timber Press (2004)

ISBN 088192640X

Title Roof Gardens: History, Design and Construction

Authors Theodore H. Osmundson

Publisher W. W. Norton and Company Inc. (1999)

ISBN 0393730123

Title Green Roofs: Ecological Design and Construction

Authors Earth Pledge, foreword by William McDonough, Editor Marisa Arpels

Publisher Schiffer Publishing Limited (2005)

ISBN 0393730123

Title Green Roofs,

Author Katrin Scholz-Barth

Publisher Federal Energy Management Program (FEMP), Federal Technology Alert, No. DOE/EE-0298

Available at http://www.nrel.gov/docs/fy04osti/36060.pdf

Title Green Roof Systems: A Guide to the Planning, Design and Construction of Building Over Structures

Authors Susan Weiler, Katrin Scholz-Barth

Publisher John Wiley and Sons

ISBN 0471674958

Title The Green Roof Infrastructure Monitor,

Authors Several

Publisher Green Roofs for Healthy Cities

Available at www.greenroofs.ca

Organizations promoting green roofs

Name Green Roofs for Healthy Cities (GRHC) North America Inc.

Description GRHC based in Toronto is a non-profit industry association consisting of public and private organizations and individuals.

Website http://www.greenroofs.org/

Name Greenroofs.com

Description Greenroofs.com is the international green roof industry’s resource and online information portal. Greenroofs.com serves animportant role as the information database and clearinghouse for the green roof movement worldwide. The website contains acompilation of information and is easily the first stop for green roof information.

Website http://www.greenroofs.com/

Name LivingRoofs

Description U.K. based organization promoting green roofs. It is a non-profit organisation established to promote, advise upon and seekresearch into green roofs and similar structures within the context of urban and rural regeneration.

Website http://www.livingroofs.org



123

Description The objectives of the institute are to promote an increased use of green roofs in Scandinavia, to provide evidence for thepositive impact of green roofs on urban ecology, and to provide background material for legislation, building standards,instructions, loan regulations and state grants. It is home to the Scandinavian Green Roof Journal.

Website http://www.greenroof.se/

CMHC green roof resources

Title Design Guidelines for Green Roofs

Author Steven Peck and Monica Kuhn

Available from http://www.cmhc.ca/en/inpr/bude/himu/coedar/loader.cfm?url=/commonspot/security/getfile.cfm&PageID=70146

Title Greenbacks from Green Roofs: Forging a New Industry in Canada

Author Steven Peck, Monica Kuhn, Chris Callaghan, Brad Bass

Available from http://www.cmhc.ca/en/inpr/su/waco/alstmaprrepr/alstmaprrepr_001.cfm

Title Waterfall Building Green Roof Case Study, Vancouver, B.C.

Author NA

Available from http://www.cmhc.ca/en/inpr/bude/himu/inbu/loader.cfm?url=/commonspot/security/getfile.cfm&PageID=58783

Title Merchandise Loft Building Green Roof Case Study, Toronto, ON

Author NA


Title Green Roof Herb Garden Case Study, Fairmont Waterfront Hotel, Vancouver B.C.

Author Aysa N. September, Steven Peck


Title Soka-Bau Green Roof Case Study, Wiesbaden, Germany

Author Goya Ngan


Organizations promoting sustainable buildings

Name United States Green Building Council (USGBC)

DescriptionThe home of LEED. The U.S. Green Building Council is the nation’s foremost coalition of leaders from across the buildingindustry working to promote buildings that are environmentally responsible, profitable and healthy places to live and work.

Website http://www.usgbc.org/

Name Green Resources Links including Canadian Funding Opportunities

Description Part of the Canadian Green Building Council website

Website http://www.cagbc.org/green_resources/links.php

Name Canadian Green Building Council (CGBC)

Description The Canadian home of LEED. Canadian counterpart of the U.S. Green Building Council.

Website http://www.cagbc.org/

Name International Initiative for a Sustainable Built Environment (IISBE)

Description Energy and Environmental Issues in the Building Sector: to advance the energy and environmental performance ofbuildings through the creation, exchange and application of appropriate and timely information. Provides many Canadiancase studies of green buildings.

Website http://greenbuilding.ca/

Visit our home page at www.cmhc.ca

09/05/2006

green Roofs - BCIT Commons · green roof layers based on their vision and guiding principles....

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