Report on the Environmental Benefits and Costs of Green Roof Technology for the City of Toronto

Doug, Banting and Hitesh, Doshi and James, Li and Paul, Missios (2005): Report on the Environmental Benefits and Costs of Green Roof Technology for the City of Toronto.

Abstract

This report presents the findings on the municipal level benefits of implementing green roof technology in the City of Toronto. Beyond this report, which addresses the immediate needs of the City of Toronto in assisting them to formulate appropriate programs and policies, the Ryerson team has been charged by OCE-ETech to develop a generic technological solution that can be used to predict the costs and benefits related to green roofs. This work is ongoing and is not reported here. Of the many benefits of green roofs reported in the study, the ones that had the most quantifiable monetary value based on currently available research data are: benefit from stormwater flow reduction including impact on combined sewer overflow (CSO), improvement in air quality, reduction in direct energy use, and reduction in urban heat island effect. The literature review indicated other benefits that could not be quantified in this report. These benefits included: aesthetic improvement of urban landscape, increase in property values, benefits resulting from green roofs used as amenity spaces, use of green roof for food production, and increased biodiversity. Further work is needed to quantify these benefits.

• Item Type: MPRA Paper
• Language: English
• Keywords: green roofs, economic benefits, environment, cost-benefit analysis, stormeater flow, air quality, energy use, urban heat island
• Subjects: Q - Agricultural and Natural Resource Economics ; Environmental and Ecological Economics > Q5 - Environmental Economics; Q - Agricultural and Natural Resource Economics ; Environmental and Ecological Economics > Q5 - Environmental Economics > Q51 - Valuation of Environmental Effects; Q - Agricultural and Natural Resource Economics ; Environmental and Ecological Economics > Q5 - Environmental Economics > Q52 - Pollution Control Adoption and Costs ; Distributional Effects ; Employment Effects; Q - Agricultural and Natural Resource Economics ; Environmental and Ecological Economics > Q5 - Environmental Economics > Q58 - Government Policy

References

Acks, K. (2003), "A framework for cost-benefit analysis of green roofs: initial estimates," pers.comm.

Adams B.J. and Fabian P. (2000) Urban stormwater management planning with analytical probabilistic models, John Wiley Sons Inc.

Akbari, H., (2002) Heat island reduction: an overview - effects of trees and implementation issues.

Presentation by Lawrence Berkeley Laboratory at the University of Pennsylvannia, LAPR 760, November 13th, 2002.

Akbari, H. (2003). Measured energy savings from the application of reflective roofs in two small nonresidential buildings. Energy. Vol 28. Issue 9, 953-967.

Akbari H., Bretz S., Taha H., Kurn D. and Hanford J. (1990). Peak power and cooling energy savings of high- albedo roofs. Energy and Buildings-Special Issue on Urban Heat Islands and Cool Communities 25(2), 117–126.

Akbari, H and Konopacki, S., 2004. Energy effects of heat-island reduction strategies in Toronto, Canada. Energy. 29, 191-210 (LBL Study).

Akbari, H., Konopacki, S., & Pomerantz, M., (1999). Cooling energy savings potential of reflective roofs for residential and commercial buildings in the United States. Energy. Vol 24, Issue 5. 391- 407.

Akbari, H., Kurn, D.M., Bretz, S.E., Hanford, J.W. (1997). Peak power and cooling energy savings of shade trees. Energy and Buildings, 25, 139 – 148.

Akbari, H., Pomerantz, M., & Taha, H., (2001). Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Solar Energy, 70, 3, 295-310.

Alcazar, S.S. and Bass, B., 2005. Energy performance of green roofs in a multi storey residential building in Madrid. University of Toronto.

Arrow, K. J., Parikh, J. and Pillet, G. (1996), Decision Making Framework to Address Climate Change, Intergovernmental Panel on Climate Change, Geneva, Switzerland.

Bass, B., Currie, B.A., Perks, T., & So, D. (2004). Effects of Green Elements on Graduate Students Perception of Wellness - #30 Charles Street Toronto. (unpublished).

Bass, B. and B. Baskaran. 2003. Evaluating Rooftop and Vertical Gardens as an Adaptation Strategy for Urban Areas. Institute for Research and Construction, NRCC-46737, Project no. A020, CCAF Report B1046. Ottawa, Canada: National Research Council.

Bass, B., Krayenhoff, E.F., Martilli, A., Stull, R.B. and Auld, H. 2002. Modelling the impact of green roof infrastructure on the urban heat island in Toronto. Green roofs Infrastructure Monitor 4(1).

Bateman, I. J., Lovett, A. A., and Brainard, J. S. (2004), Applied Environmental Economics: A GIS Approach to Cost-Benefit Analysis, Cambridge University Press, Cambridge.

Brenneisen, S., (2003). The Benefits of Biodiversity from Green Roofs – Key Design Consequences. Proceedings from Greening Rooftops for Sustainable Communities, First North American Green Roof Infrastructure Conference, May 29th and 30th, Chicago, 2003.

Brown, S. V. and Shabanova, K. (2003), "Benefit-cost analysis of the "living roof" project, pers.comm.

Camp, T.R. 1963. Water and its impurities, Reinhold, New York.

Cline, W. R. (1992), The Economics of Global Warming, Institute for International Economics, Washington, DC.

Chandler, T.J. 1976. Urban Climatology and relevance to Urban Design. Technical Note No. 149. World Meteorological Organization, CH-1211, Geneva 20, Switzerland.

Cheney, C., 2005, Green Roofs: Ecological Design and Construction. Earth Pledge Foundation. Lancaster: Schiffer Publishing.

Currie, Beth Anne, (2005), Air Pollution Mitigation with Green Roofs Using the UFORE Model, Unpublished MASc Thesis, Ryerson University, Toronto.

Currie, B.A., (2005). Urbanspace PROPERTY Group, Environment, Health and Safety Coordinator. Pers comm.

Cohnstaedt, J., Shields, J., & MacDonald, M., (2003). New workplace commons, a study of innovative support for cultural and social enterprises in both the not-for-profit and for-profit sectors (401 Richmond). Commissioned by Canadian Heritage; City of Toronto, Culture Division; and Ministry of Culture. (unpublished)

Crackowski, J.M., Nasar, J.L. (2003). The restorative effects of roadside vegetation- implications for automobile driver anger and frustration. Environment and Behaviour, 35, 736-751.

Del Barrio, E.P., (1998). Analysis of the green roofs cooling potential in buildings. Energy and Buildings, 27, 179-193.

Dramstad, W.E., Olson, J.D. and Forman, R.T.T., 1996, Principles in Landscape Architecture and Land-Use Planning, Harvard University Graduate School of Design, Island Press, and American Society of Landscape Architects, Washington D.C.

Dunnet, N., and Kingsbury, N, (2004), Planning Green Roofs and Living Walls, Timber Press, Portland, Oregon, p 254.

England, E., Morgan, B., Usrey, L., Greiner, M., Blackmann, C. (2004), "Vegetated roofing technology: an evaluation," pers.comm.

Gedge, D., (2003). From Rubble to Redstarts…Black Redstart Action Plan Working Group. Proceedings from Greening Rooftops for Sustainable Communities, First North American Green Roof Infrastructure Conference, May 29th and 30th, Chicago, 2003.

Goom, S. (2003), "Green roofing the Canadian Centre for Pollution Prevention," pers.comm..

Graham, P., and Kim, M., 2003, Evaluating the Stormwater Management Benefits of Green Roofs Through Water Balance Modeling, Greening Rooftops for Sustainable Communities Conference, May29-30, 2003; Chicago, Illinois.

Green Roofs for Healthy Cities (GRHC) 2003, Public Benefits of Green Roofs, available online at http://www.green roofs.org/index.php?page=publicbenefits

Herzog, T.R., Maguire, C.P., Nebel, M.B., (2003). Assessing the restorative components of environments. Journal of Environmental Psychology, 23, 159-170.

Hogarth, L.M. 1977. “The conception, design, and construction of metropolitan Toronto mid-Toronto interceptor sewer,” Canadian Journal of Civil Engineering, 4(1), 47-56.

Jennings, G., Hunt, B., Moran, A, 2003, A North Carolina Field Study to Evaluate Green roof Runoff Quantity, Runoff Quality, and Plant Growth, ASAE Annual International Meeting, Las Vegas, Nevada, USA, 27-30 July 2003.

Johnston, J. and Newton, J., 1993, Building Green, A Guide for Using Plants on Roofs, Walls and Pavements, The London Ecology Unit, London.

Kaplan, R. (1993) The role of nature in the context of the workplace. Landscape and Urban Planning, 26, 193-201.

Kats, G., 2003, The Costs and Financial Benefits of Green Buildings.

Kohler, M., Schmidt, M., Grimme, F.H., Laar, M., Paiva, V.L.A., and Tavares, S. 2002. Green roofs in Temperate climates and in the hot-humid tropics - far beyond the aesthetics. Environmental Management and Health. 13(4) 382-391.

Kenney, W.A., (2001).The Environmental role of Toronto’s urban forest. University of Toronto, Department of Forestry, Toronto, Ontario.

Landsberg, H.E., 1981, The Urban Climate. International Geophysics Series No.28, Academic Press, New York.

Laumann, K., Garling, T., Morten, Stormakr, K., (2003). Selective attention and heart rate responses to natural and urban environments. Journal of Environmental Psychology, 23, 125-134.

Leather, P., Pygras, M., Beale, D., Lawrence, C., (1998). Windows in the workplace: sunlight, view, and occupational stress. Environment and Behaviour, 30, 739-762.

Liesecke, H., 1993, Wasserruckhaltung bei extensiven dachbegrunungen, Deutscher Gartenbau, 47 (34): 2142-2147.

Liesecke, H., 1998, Das Retentionsvermogen von Dachbegrunungen, Stadt Und Grun, 47:46-53.

Liesecke, H., 1999, Extensive begrunnug bei °dachneigung, Stadt und Grun, 48(5):337-346.

Liptan, T., (2003). Planning, Zoning and Financial Incentives for Ecoroofs in Portland, Oregon. Proceedings from Greening Rooftops for Sustainable Communities, First North American Green Roof Infrastructure Conference, May 29-30th, Chicago.

Liu, K., 2003, Engineering Performance of Rooftop Gardens Through field evaluation, Proceedings of the 18th International Convention of the Roof Consultants Institute: 13-16 March, 2003, Tampa, FL, pp.93-103.

Liu, K. and B. Baskaran. 2003. Thermal Performance of Green Roofs Through Field Evaluation. In Proc. Greening Rooftops for Sustainable Communities: Chicago 2003: May 29-30, 2003; Chicago, Illinois.

MacIver, D., and Urquizo, N., 1999, Atmospheric Change in Canada: An integrated Overview, Environment Canada, Ottawa.

Monterusso, M., 2003, Species Selection and Stormwater Runoff Analysis from Green roof System, Department of Horticulture, Michigan State University.

Niachou, A., Papakonstantinou, K., Santamouris, M., Tsangrassoulis, A., and Mihalakakou, G., 2001. Analysis of the green roof thermal properties and investigation of its energy performance. Energy and Buildings. 33, 719-729.

Nowak, D.J., & Crane, D.E., (1998) The Urban Forest Effects (UFORE) Model: Quantifying Urban Forest Structure and Functions. Integrated Tools Proceedings. Boise, Idaho, USA, August 16-20, 1998.

OCCD, 2005, last viewed at http://www.oecd.org/dataoecd/48/18/18598721.pdf, September 2005.

Oke, T. R.: 1995, 'The Heat Island of the Urban Boundary Layer: Characteristics, Causes and Effects', in J. E. Cermak et al. (eds.), Wind Climate in Cities, Kluwer Academic Publishers, Dordrecht, Boston, pp. 81-107.

Oke, T. R., 1987: Boundary Layer Climates. Wiley and Sons, 372.

Onmura, S., Matsumoto, M. and Hokoi, S., 2001. Study on evaporative cooling effect of roof lawn gardens, Energy and Building 33, 653-666.

Parker, J.H. 1982. Landscaping to reduce the energy used in buildings, Journal of Forestry 81 (2) 82-84.

Pearce, D. W. and Ulph, D. (1998), "A social discount rate for the United Kingdom," in Pearce, D. W. (ed.), Economics and Environment: Essays on Ecological Economics and Sustainable Development, Edward Elgar, Cheltenham, 268-85.

Peck, S., Callahan, C., Kuhn, M., and Bass, B., (1999), Greenbacks from Green roofs: Forging a New Industry in Canada, CMHC, Toronto.

Robinson, D., (2005). Mountain Equipment Coop, Social and Environment Coordinator. Pers comm.

Rowe, D., Rugh, C., Vanwoert, N., Monterusso, M., Russell, D., 2003, Green Roof Slope, Substrate Depth, and Vegetation Influence Runoff, Michigan State University Dept. of Horticulture and Michigan State University Dept. of Crop and Soil Sciences, Greening Rooftops for Sustainable Communities Conferenece, May29-30, 2003., Chicago.

Sailor,D.J., 1995. Simulated Urban Climate response to modification in surface Albedo and Vegetative Cover Journal of Applied Meteorology 34(7) 1694-1704.

Schade, C., 2000, Wasserruckhaltung und Abflußbeiwerte bei dunnschichtigen extensivebegrunungen, Stadt und Grun, 49(2): 95-100.

Taylor, A., et al (January 2001) Coping with ADD: The Surprising Connection to Green Play Settings. Environment and Behavior, Vol. 33 No.1, 54-77.

Thompson, A., (1998), Grass-roofs movement in landscape architecture, The magazine of the American Society of Landscape Architects, 88:47-51.

Treasury Board of Canada Secretariat (1998), Benefit Cost Analysis Guide, available online at http://www.tbs-sct.gc.ca/fin/sigs/Revolving_Funds/bcag/BCA2_E.asp

Wong, N.H., Chen, Y., Ong, C.L. and Sia, A., 2003. Investigation of thermal benefits of rooftop garden in the tropical environment. Building and Environment 38, 261-270.

Wong, N. H., Tay S. F., Wong, R., Ong, C. L., Sia, A. (2003), "Life cycle cost analysis of rooftop gardens in Singapore," Building and Environment 38, 499.

Wong, N.H., Cheong, D.K.W., Yan, H., Soh, J., Ong, C.L., Sia, A., 2003. The effects of rooftop gardens on energy consumption of a commercial building in Singapore. Energy and Buildings. 35, 353-364.

Yaffe, B., (2004), Air Pollution Burden of Illness in Toronto: 2004 Summary, Toronto Public Health, City of Toronto, Toronto.

Yok, T.P., Sia, A., (2005). A Pilot Green Roof Research Project in Singapore. Proceedings from Green Roofs for Healthy Sustainable Cities Conference, Washington D.C., May 2005.

Zinco Roof Gardens (1997), The Green Roof Planning Guide, Holland, Zinco Inc.

Zeidler, M., (2005). Urbanspace PROPERTY Group, Building owner. Pers comm.

Zubevich, Kipling. (2004) The Search for the Sacred in the Concrete Jungle. (via link on the Ecopsychology web site, July 2004)