Green Roof DesignAmanda Kuhnley

Gaia Principle

• Ancient Greece – holistic approach• Gaia – primordial Earth goddess

• James Lovelock• Gaia hypothesis (1979)• A complex entity involving the Earth’s

biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet

Gaia Foundation

• Founded in 1994• Development of models for

sustainable societies • Holistic approach to living• Reflecting nature and Mother Earth

• Gaia principle

(Gaia, 2007)

Malta Energy Situation• Total reliance on fossil fuels • Minimal exploration of alternative fuels• Increase in oil prices left no other option than

increase in electricity prices• 40% total energy consumed in EU

• 2/3 in residential homes• 70% - heating and cooling – inefficiency of homes

• Significance of EPBD

(Warren, 2002)

Energy Performance Building Directive (EPBD)• Reduce the consumption of energy in

buildings in such a way that it will inspire more energy efficiency without impairing the level of thermal comfort of the occupants

• Malta is a full member of the EU and must follow the provisions set up (Buhagier, 2006).

Introduction

• Buildings change the flow of energy and matter• Increase sound insulation• Increase fire resistance• Increase longevity of roof membrane• Reduce energy required for indoor

climate control• Mitigate storm water runoff

Introduction

• Other potential benefits• Green-space amenity• Habitat for wildlife• Air-quality improvement

History of Green Roofs

• Ancient roof gardens• Hanging gardens of Babylon

• Intensive - investment

http://www.skepticworld.com/ancient-monuments/

Green Roofs in Germany

• 1970’s• Technology was quickly embraced • Interdiscipinary research

• Incentives introduced• Promote green-roof technology• Improve environmental standards

• Building law requirements• Green roofing in urban areas

Green Roofs in Germany

• Success• 13.5 million square meters per year• 14% all new flat roofs will be green• Market increase - sloped green roofs• Accessible green roofs – driving

force behind neighborhood revitalization

http://www.santamonicapropertyblog.com/wp-content/uploads/2009/02/green-roof-in-norway.jpg

Extensive Green Roofs

• Modern modification of the roof-garden concept• Shallower substrates• Require less maintenance• More strictly functional

Extensive Green Roof

Simplest Design

• Insulation layer• Waterproofing membrane• Layer of growing medium• Vegetation layer

http://www.sierraclubgreenhome.com/cms/wp-content/uploads/green-roof-1.bmp

Green Roof Vegetation

• Challenges• Moisture stress, extreme drought• Extreme temperatures• High light intensities• High wind speeds

• Adaptations• Compact growth• Evergreen foliage• Succulant leaves• Water storage capacity

Green Roof Vegetation

• Thermal properties – monocultural types

• Maximizing Performance – diverse functional types(Kolb, 1993)

Ecosystem Services Provided

• Storm-water management• Energy conservation• Urban habitat provision

Storm-Water Management

• Make use of existing roof space • Prevent run-off • Store water during rainfall• Rate of runoff• Depth of substrate• Slope of roof• Type of plant community• Rainfall patterns (Dunett, 2004)

Storm-Water Management

• Plan Bleu – Mediterranean Strategy for Sustainable Development (2008)• increasing the storage and production of

water from other sources through incentives aimed at encouraging the construction of rainwater harvesting cisterns and the introduction of grey water recycling facilties in households (Sapiano, 2008)

• Establishes tax-rebate for water savings appliances• Could green roofs fall under this rebate?

Energy Conservation

• Reduce heat flux• Promoting evapotranspiration• Physically shading the roof• Increasing insulation and thermal

mass (Gaffin, 2006)

• Other technology

Urban Habitat Provision

• Discussion on biodiversity• Invertebrate and avian communities

• Humans• Aesthetic and psychological benefits• Food production – economic and

educational benefits• Reduce sound pollution• Absorb sound waves and preventing

inward transmission

Optigreen

Blurring the line between landscape and building…

Blurring the line between landscape and building…

• Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas.

• Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas.