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XV Symposium 11 Urban Plant Diversity in the Mediterranean

OPTIMA meeting in Montpellier

GREEN ROOFS AND LIVING WALLS – BENEFITS AND CHALLENGES

Katia PERINI

Department of Sciences for Architecture, University of Genoa (Italy)

2 [email protected] - www.ecosystemics.eu

Chicago

Chicago Delft Freiburg

Sydney San Francisco Seoul

Milan New York City Italy Alba, Italy

[email protected] - www.ecosystemics.eu 3

Bolzano

Vietnam Paris Amiens Copenhagen

London Lima Milan Amsterdam

Seoul


ENVIRONMENTAL AND ECOLOGICAL IMBALANCES:

URBAN HEAT ISLAND

RAINWATER MANAGEMENT

AIR QUALITY

BIODIVERSITY LOSS

ECOSYSTEM HEALTH

URBAN AREAS

5

BENEFITS OF VEGETATION

[email protected] - www.ecosystemics.eu

INTENSIVE GREEN ROOF

EWHA WOMAN’S UNIVERSITY, DOMINIQUE PERRAULT, SEOUL


GREEN ROOFS

SEMI INTENSIVE GREEN ROOF

LIBRARY DELFT UNIVERSITY OF TECHNOLOGY, MECANOO, DELFT


GREEN ROOFS

EXTENSIVE GREEN ROOF WITH SOLAR PANELS, FREIBURG


GREEN ROOFS


http://commons.bcit.ca/greenroof/faq/why-green-roofs-benefits/ GREEN ROOFS – BENEFITS: BUILDING ENVELOPE

ENERGY SAVING FOR AIR

CONDITIONING: SHADING AND

EVAPORATION

ENERGY SAVING FOR HEATING:

EXTRA INSULATION AND WIND

PROTECTION

ROOF PROTECTION


ACCORDING TO ROSENZWEIG ET AL. (2006) WITH 50% OF ROOFS IN

NYC COVERED BY VEGETATION, UHI COULD BE REDUCED BY 0.8°C.

Image www.gogreeninggotham.org

GREEN ROOFS – BENEFITS: UHI MITIGATION


GREEN ROOFS – BENEFITS: WATER MANAGEMENT SOURCE: OBERNDORFER E, LUNDHOLM J, BASS B, ET AL. 2007


GREEN ROOFS – ENVIRONMENTAL SUSTAINABILITY SOURCE: KOSAREO E RIES (2006)

RELATIVE PERFORMANCE OF THE THREE ROOF ALTERNATIVES IN TERMS OF

EQUIVALENCE FACTORS IN THE OZONE LAYER DEPLETION, ACIDIFICATION,

EUTROPHICATION, AND GLOBAL WARMING IMPACT CATEGORIES.

15

INPS GREEN FACADE PILOT PROJECT. GENOA, ITALY


16

INPS GREEN FACADE PILOT PROJECT. GENOA, ITALY


17

Rhincosperma jasminoide

Phlomis fruticosa

Atriplex halimus

Teucrium chamaedris

Buxus sempervirens rotundifolia Dorycnium hirsutum

Nerium oleander Euonymus bravo

Hebe franciscanus Cistus crispus Cistus Jessami beauty

Viburnum tinus eve price


INPS GREEN FACADE PILOT PROJECT

18

Evaluation of the environmental, economic, and social benefits of green envelopes in dense urban areas

Main objectives of the research:

Plant species selection and monitoring

Effectiveness of plant species for air quality improvement

Effectiveness of plant species for energy performances

Plant species health and growth



19




Quantification of air quality improvement (fine dusts, NO2)

in collaboration with the Delft University of Technology, Dr. Marc Ottelé

Collecting capacity of fine dusts

NO2 monitoring



20





Energy performances improvement of the building envelope

In collaboration with Ricerca sul Sistema Energetico (RSE) S.p.A. (Research on energy system)

Monitoring the cooling potential of green facades (energy demand for air conditioning)

Monitoring the insulation properties of green facades (energy demand for heating)



21






Evaluation of users’ social perception

Qualitative and quantitative analysis

Surveys and interviews to INPS employees, residents and workers in the area



22







Evaluation of economic impact of vertical greening systems

CBA: analysis of costs (installation and maintenance) in relation to economic benefits



23







Evaluation of economic impact of the vertical greening system

Evaluation of environmental impact of the vertical greening system

LCA: evaluation of the environmental burden of vertical greening related to microclimatic and environmental

benefits



24

INPS GREEN FACADE – USERS PERCEPTION

Phase 1: quantitative analysis 3 months before the installation of the INPS green facade

July 2014

59 people interviewed:

People working and/or living in the neighbourhood (44,1% )

INPS employees (55,9%)


25

Survey on green facades of the University of Genoa, Department of Architectural Science (conducted in Italy, original version language Italian) ☐ Employee of INPS office in Sestri Ponente, Genoa ☐ Person working in Sestri Ponente, Genoa ☐Person living in Sestri Ponente, Genoa Some examples of green facades Have you ever seen one or more? ☐yes ☐no Have you ever heard about it? ☐yes ☐no Select the importance of each of the POSITIVE EFFECTS of green facades in a city rating from 1 to 5 (highest): More nature in cities ☐1 ☐2 ☐3 ☐4 ☐5 Visually enhanced cityscape ☐1 ☐2 ☐3 ☐4 ☐5 Better wellbeing of citizens ☐1 ☐2 ☐3 ☐4 ☐5 Increase of biodiversity (small animals) ☐1 ☐2 ☐3 ☐4 ☐5 Air quality improvement ☐1 ☐2 ☐3 ☐4 ☐5 Shading and cooling in summer ☐1 ☐2 ☐3 ☐4 ☐5 Thermal insulation during winter season ☐1 ☐2 ☐3 ☐4 ☐5 Improvement of the city environment ☐1 ☐2 ☐3 ☐4 ☐5 Reduction of noise pollution ☐1 ☐2 ☐3 ☐4 ☐5 Environmental education ☐1 ☐2 ☐3 ☐4 ☐5 Building aesthetic ☐1 ☐2 ☐3 ☐4 ☐5

Select the importance of each of the NEGATIVE EFFECTS of green facades in a city rating from 1 to 5 (highest): Frequent maintenance ☐1 ☐2 ☐3 ☐4 ☐5 Problems related to falling leaves ☐1 ☐2 ☐3 ☐4 ☐5 Problems with building restoration ☐1 ☐2 ☐3 ☐4 ☐5 Obstruction of gutter or standpipes ☐1 ☐2 ☐3 ☐4 ☐5 Less daylight inside the building ☐1 ☐2 ☐3 ☐4 ☐5 Damages to the facades ☐1 ☐2 ☐3 ☐4 ☐5 Dirty due to the presence of animals ☐1 ☐2 ☐3 ☐4 ☐5 More insects ☐1 ☐2 ☐3 ☐4 ☐5 Management problems ☐1 ☐2 ☐3 ☐4 ☐5 Additional costs ☐1 ☐2 ☐3 ☐4 ☐5 Higher danger of theft ☐1 ☐2 ☐3 ☐4 ☐5

26


July 2014

59 people interviewed


0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

NEGATIVEEFFECTS

INPSemployees

peopleworking/livinginGenoaS.P.

fullsample

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

POSITIVEEFFECTS

"INPSemployees"

"peopleworkin/livinginGenoaS.P."

fullsample


27


July 2014

59 people interviewed:

People working and/or living in the neighbourhood (44,1% )

INPS employees (55,9%)

Most recognised positive effect: air quality improvement

Most recognised negative effect: more insects

Total scores:

People working and/or living in the neighbourhood: 56,8% positive - 43,2% negative

INPS employees: 47,4% positive - 52,6% negative




INPS GREEN FACADE

29

Phase 2: qualitative analysis 6 months after the installation of the INPS green facade

May 2015, with Roberta Prampolini

21 semi-structured interviews to a significant sample

Residents in the neighbourhood – 106 answers

People working in the neighbourhood – 85 answers

INPS employees – 55 answers

Investigation topics:

1. Photo elicitation to favour a dialog on the INSP Green facade

2. Green areas in the neighbourhood

3. Vertical green in other areas of the city



30




1. Photo elicitation to favour a dialog on the INSP Green façade

Reduced knowledge of the technology

Positive opinion due to: aesthetic, wellbeing, environmental and energy effects

Negative effects (less) due to: insects and maintenance needs

Critics arise during the installation were mentioned – only 3 of 21 highlight negative opinions



31




1. Photo elicitation to favour a dialog on the INSP Green facade

2. Green areas in the neighbourhood

• Not enough

3. Vertical green in other areas of the city

• Public funds

• The results show that communication plays a key role

• Younger people show positive opinion about the project



32



to improve the area in

a very busy street, I

think it was built there

for a reason!

some green..

Something new!

A building with flowers

with an aesthetic value

only, a modern project,

lets say!

It could be

positive!

.. In addition it

could also protect

the facade, so..

something positive

for air pollution

I was curious when I

saw the facade.. I

thought it was a waste

of money then I

understood this is a

smart idea!



Quantification of air quality improvement

PM collecting capacities

INPS GREEN FACADE – AIR QUALITY

SOURCE: PERINI ET AL., 2016 IN PRESS



PM collecting capacities – UNIGE-DSA with TUDelft





ESEM analysis





ESEM analysis – IMAGE J counting





0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

>10 7.5-10 5-7.5 2.5-5 2-2.5 1.5-2 1-1.5 0.5-1 <0.5

Par

ticl

e n

um

ber

in 1

mm

2

Particle size (µm)

CJ_Oct average HH_Oct average PF_Oct average RJ_Oct average

Number and size (µm) of particles in 1 mm2 for Hedera helix, Cistus jessamy beauty, Phlomis fruticosa,

Rhyncospermum jasminoide, based on 100x, 250x, 500x magnifications





Monitoring the cooling potential of green facades

INPS GREEN FACADE – ENERGY

SOURCE: PERINI ET AL., 2016 IN PRESS




Monitoring the cooling potential of green facades

Comparison between external surface temperatures in presence and in absence of

the vertical greening system

INPS GREEN FACADE – ENERGY


Evaluation of economic impact of vertical greening systems

CBA: analysis of costs (installation and maintenance) in relation to economic benefits

Evaluation of environmental impact of the vertical greening system

LCA: evaluation of the environmental burden of vertical greening related to microclimatic and

environmental benefits

INPS GREEN FACADE


Greening systems analysed:

A. direct greening system

B. indirect greening system (stainless steel mesh)

C. LWS based on planter boxes

D. LWS based on felt layers

Energy Energy saving for heating

A. Direct green: 1.2%

B. Indirect green: 1.2%

C. LWS planter boxes: 6.3%

D. LWS felt layers: 4%

Energy saving for cooling in Mediterranean climate: 43%

(Alexandri and Jones, 2007).

Source: Ottele and Perini, 2011

Llife cycle analysis of greening systems:

environmental burden profile in relation with

the energy savings for air conditioning and heating

Calculation of the environmental impact of:

• production

• use-maintenance

• disposal-waste

VERTICAL GREENING – ENVIRONMENTAL SUSTAINABILITY

42

SOSTENIBILITÀ ECONOMICA

Costi iniziali (messa in opera)

Manutenzione

dismissione

Benefici (economici) legati alla messa in opera di sistemi per il verde verticale

Personali Risparmio energetico: riscaldamento (isolamento extra) e condizionamento

Durabilità dell’intonaco

Real estate: aumento del valore immobiliare

Incentivi

Sociali Climate change: riduzione CO2

Miglioramento qualità dell’aria: NO2, PM

10, SO

2

Habitat: aumento biodiversità

Isola di calore: riduzione temperatura dell’aria

Estetica: miglioramento dell’area

Analisi costi benefici di un edificio per u ici a Genova progettato per lo studio (simulazione)

Vertical greening systems and economic sustainability

CosteBenefit Analysis of an office building designed for the study located in Italy (dense city).

• Initial costs (installation)

• Maintenance costs

• Disposal costs

(Economic) benefits related to the installation of vertical greening systems:

Personal

• Energy saving: heating (additional insulation) and air-conditioning

• Longevity: cladding durability

• Real estate: increase of property value

• Incentives and support: tax reduction

Social

• Climate change: carbon dioxide reduction

• Air quality improvement: NO2, PM10, SO2 reduction

• Habitat: increase of biodiversity

• Urban heat island: air temperature reduction

• Aesthetic: increase of area value

Source: Perini and Rosasco, 2015


VERTICAL GREENING – ECONOMIC SUSTAINABILITY

43

Author's personal copy

Since the latters are very low (resulting in avery small impact on

the total values) a separate analysis of the indicators is not pre-

sented. It has to be specified that e differently from other inter-

vention in the building sector carried out for profit (like public

works) e in the case of greening systems the economic sustain-

ability is reached when the NPV ispositive (that iswhen incomes

prevail on costs) and theannual Internal Rateof Return (IRR) have

similar values to the passive interest rate applied by credit in-

stitutes to finance an intervention (in Italy for the time being it is

about 5%per year).ConsideringthePay Back Period (PBP), themost

favourable economic conditions take placewhen the PBPis lower,

that is the sooner the collected economic benefits will equal the

costs incurred.

4.1. Direct green façade

Thevaluesobtained for theeconomic indicatorsshow that this

greening system is sustainable for all the scenarios assumed

(Table 7). The Net Present Value (NPV) goes from a minimum of

9500 V (worst scenario) to amaximum of 30,139 V (best scenario;

Graph 1). Also the internal ratesof return are all above acceptable

economic thresholds (Graph 2); these go from aminimum of 7.7%

(worst scenario) to a maximum of 10.7%(best scenario). The num-

ber of years needed for the economic benefits to reach the costs

variesfrom amaximum of 24 years(worst scenario) toaminimum

of 16 years (best scenario). These values are due to the low instal-

lation, maintenance, and disposal costsof the direct green façade.

4.2. Indirect green façade

The indirect green façade, wherevegetation issupported by an

HPDE mesh or by a steel mesh, can be considered economically

sustainable for thebest scenario; differently in themiddlescenario

only the greening system based on the HDPE mesh (2A) is sus-

tainable (Table 7). In particular, for this system positive NPVsvary

between 2061V (middlescenario) to14,713V (best scenario; Graph

1) with IRRvaluesrespectivelyof 5.2%and5.8%(Graph2) andaPBP

of 33and 16 years. Theindirect green façade (2Ae2B) compared to

thedirect one(green façade) (1) hashigher installation (dueto the

supporting system) and disposal costs; thishappensespecially for

the indirect green façade supported by asteel mesh (2B).

4.3. Indirect green façadecombined with planter boxes

The indirect green façade combined with planter boxes (3A.

HDPEsupport and planter boxesand 3B. steel support and planter

boxes) presentsan economic sustainability (minimum) in the best

scenario; the other two scenarios are under the limit of accept-

ability. For the best scenario the NPV is positive with only 289 V,

with IRRof 4.5%andPBPof 16years(Table7; Graphs1and2).Asfor

the indirect green façade (2Ae2B), installation costs (not only for

the supporting system but also for the irrigation system) and

maintenancecosts for vegetation and irrigation system are high.

4.4. Living wall system

The living wall system analysed in this study does not show e

for any of the three different scenarios assumed e any margin of

economicsustainability; theNPVsareall negativeaswell astheIRR

valueswhich arenot defined (asthesedonot exist; Table7; Graphs

1 and 2). This vertical greening system has high installation costs

for the pre-vegetated panelsand maintenance costs for thewhole

system(panelstobereplaces,plant species, irrigation system).Due

to these costs within the life cycle, after the initial costs for the

installation, the annual benefits overtake the annual costs (for

maintenance) of a few tensof euros, value which is insufficient to

pay back the incurred costs (Graph 3).

4.5. Overview

Beyond the specificity of the case study examined, the CBA

shows that for these systems both installation and maintenance

costsplay adecisiverolefor sustainability; thelatter isparticularly

relevant in the case of systems 3 (indirect green façade combined

with planter boxes) and 4 (living wall system). For these two sys-

tems (3e4) personal and social benefits are slightly higher than

maintenancecosts, preventing from arecovery of initial costs.

40

60

80

100

120

€x 1

00

0

Costs

Private benefits

Social benefits

0

20

Graph 3. Cost and benefit for the living wall system (4) e middle scenario.

7.7%

2.9%

0.0% 0.0% 0.0%

9.4%

5.2%

4.3%

10.7%

5.8%

4.7% 4.5%

0.0%

0

0.02

0.04

0.06

0.08

0.1

0.12

1 2A 2B 3A 3B 4

Worst

Middle

Best

Graph 2. IRR of vertical greening systems (1. direct green façade; 2A. HDPE indirect

green façade; 2B. steel indirect green façade; 3A. HDPE indirect green façade combined

w ith planter boxes; 3B. steel indirect green façade combined w ith planter boxes; 4.

living wall system).

80

-60

-40

-20

0

20

40

601 2A 2B 3A 3B 4

€x 1

00

0

Worst

Middle

Best

-140

-120

-100

-80

Graph 1. NPV of vertical greening systems (1: direct green façade; 2A: HDPE indirect

green façade; 2B: steel indirect green façade; 3A: HDPE indirect green façade com-

bined w ith planter boxes; 3B: steel indirect green façade combined w ith planter boxes;

4: living wall system).

K. Perini, P. Rosasco / Building and Environment 70 (2013) 110e 121 119

Sistemi analizzati

1: facciata verde diretta

2A: facciata verde indiretta - HDPE

2B: facciata verde indiretta - acciaio

3A: facciata verde indiretta con elementi contenitori - HDPE

3B: facciata verde indiretta con elementi contenitori - acciaio

4: living wall system

Valore Attuale Netto - valore scontato della somma dei costi e dei

benefici che si verificano nell’arco del periodo di vit a considerato

(50 anni)

Vertical greening systems analysed:

1: direct green façade

2A: HDPE indirect green façade

2B: steel indirect green façade

3A: HDPE indirect green façade combined with planter boxes

3B: steel indirect green façade combined with planter boxes


Net Present Value (NPV) of the systems analyzed - the

discounted value of the sum of costs and benefits that

occur within the period of life considered (50 years).

Author's personal copy

Since the latters are very low (resulting in avery small impact on

the total values) a separate analysis of the indicators is not pre-

sented. It has to be specified that e differently from other inter-

vention in the building sector carried out for profit (like public

works) e in the case of greening systems the economic sustain-

ability is reached when the NPV ispositive (that iswhen incomes

prevail on costs) and theannual Internal Rateof Return (IRR) have

similar values to the passive interest rate applied by credit in-

stitutes to finance an intervention (in Italy for the time being it is

about 5%per year).ConsideringthePay Back Period (PBP), themost

favourable economic conditions take placewhen the PBPis lower,

that is the sooner the collected economic benefits will equal the

costs incurred.

4.1. Direct green façade

Thevaluesobtained for theeconomic indicatorsshow that this

greening system is sustainable for all the scenarios assumed

(Table 7). The Net Present Value (NPV) goes from a minimum of

9500 V (worst scenario) to amaximum of 30,139 V (best scenario;

Graph 1). Also the internal ratesof return are all above acceptable

economic thresholds (Graph 2); these go from aminimum of 7.7%

(worst scenario) to a maximum of 10.7%(best scenario). The num-

ber of years needed for the economic benefits to reach the costs

variesfrom amaximum of 24 years(worst scenario) toaminimum

of 16 years (best scenario). These values are due to the low instal-

lation, maintenance, and disposal costsof the direct green façade.

4.2. Indirect green façade

The indirect green façade, wherevegetation issupported by an

HPDE mesh or by a steel mesh, can be considered economically

sustainable for thebest scenario; differently in themiddlescenario

only the greening system based on the HDPE mesh (2A) is sus-

tainable (Table 7). In particular, for this system positive NPVsvary

between 2061V (middlescenario) to14,713V (best scenario; Graph

1) with IRRvaluesrespectivelyof 5.2%and5.8%(Graph2) andaPBP

of 33and 16 years. Theindirect green façade (2Ae2B) compared to

thedirect one(green façade) (1) hashigher installation (dueto the

supporting system) and disposal costs; thishappensespecially for

the indirect green façade supported by asteel mesh (2B).

4.3. Indirect green façadecombined with planter boxes

The indirect green façade combined with planter boxes (3A.

HDPEsupport and planter boxesand 3B. steel support and planter

boxes) presentsan economic sustainability (minimum) in the best

scenario; the other two scenarios are under the limit of accept-

ability. For the best scenario the NPV is positive with only 289 V,

with IRRof 4.5%andPBPof 16years(Table7; Graphs1and2).Asfor

the indirect green façade (2Ae2B), installation costs (not only for

the supporting system but also for the irrigation system) and

maintenancecosts for vegetation and irrigation system are high.

4.4. Living wall system

The living wall system analysed in this study does not show e

for any of the three different scenarios assumed e any margin of

economicsustainability; theNPVsareall negativeaswell astheIRR

valueswhich arenot defined (asthesedonot exist; Table7; Graphs

1 and 2). This vertical greening system has high installation costs

for the pre-vegetated panelsand maintenance costs for thewhole

system(panelstobereplaces,plant species, irrigation system).Due

to these costs within the life cycle, after the initial costs for the

installation, the annual benefits overtake the annual costs (for

maintenance) of a few tensof euros, value which is insufficient to

pay back the incurred costs (Graph 3).

4.5. Overview

Beyond the specificity of the case study examined, the CBA

shows that for these systems both installation and maintenance

costsplay adecisiverolefor sustainability; thelatter isparticularly

relevant in the case of systems 3 (indirect green façade combined

with planter boxes) and 4 (living wall system). For these two sys-

tems (3e4) personal and social benefits are slightly higher than

maintenancecosts, preventing from arecovery of initial costs.

40

60

80

100

120

€x 1

00

0

Costs

Private benefits

Social benefits

0

20

Graph 3. Cost and benefit for the living wall system (4) e middle scenario.

7.7%

2.9%

0.0% 0.0% 0.0%

9.4%

5.2%

4.3%

10.7%

5.8%

4.7% 4.5%

0.0%

0

0.02

0.04

0.06

0.08

0.1

0.12

1 2A 2B 3A 3B 4

Worst

Middle

Best

Graph 2. IRR of vertical greening systems (1. direct green façade; 2A. HDPE indirect

green façade; 2B. steel indirect green façade; 3A. HDPE indirect green façade combined

w ith planter boxes; 3B. steel indirect green façade combined w ith planter boxes; 4.

living wall system).

80

-60

-40

-20

0

20

40

601 2A 2B 3A 3B 4

€x 1

00

0

Worst

Middle

Best

-140

-120

-100

-80

Graph 1. NPV of vertical greening systems (1: direct green façade; 2A: HDPE indirect

green façade; 2B: steel indirect green façade; 3A: HDPE indirect green façade com-

bined w ith planter boxes; 3B: steel indirect green façade combined w ith planter boxes;

4: living wall system).

K. Perini, P. Rosasco / Building and Environment 70 (2013) 110e 121 119

Sistemi analizzati

1: facciata verde diretta

2A: facciata verde indiretta - HDPE

2B: facciata verde indiretta - acciaio

3A: facciata verde indiretta con elementi contenitori - HDPE

3B: facciata verde indiretta con elementi contenitori - acciaio


Valore Attuale Netto - valore scontato della somma dei costi e dei

benefici che si verificano nell’arco del periodo di vit a considerato

(50 anni)


VERTICAL GREENING – ECONOMIC SUSTAINABILITY

44

Thank you

[email protected]

[email protected]

http://www.ecosystemics.eu

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