– – Eco-Roofs and Vancouver: A
Critical Analysis. pp 66-92 This paper discusses the lack of scientific research and critical analysis of the application of eco-roofs in biophysical environments like Vancouvers. It questions many of the potential benefits of green roofs reported in the literature in the Vancouver context, but does agree that green roofs can mitigate urban stormwater runoff. It reviews the variables that affect the stormwater retention, and notes that “an eco-roof used in conjunction with infiltration measures at grade produces a synergistic effect as the roof retains a percentage of the water until the infiltration systems are able to deal with it.”
Stormwater management
Bass, B.;
Krayenhoff, E.S.; Martilli, A.; Stull, R.B.; and Auld, H.
2003 The Impact of Green Roofs on Toronto’s Urban Heat Island. Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 12 pages
A mesoscale model is used to simulate low-level air temperature in Toronto over 48 hours in late June 2001. Heat island reduction is modelled and the potential role of green roofs is discussed.
Urban heat island mitigation
Beattie, David J. 2004 Green roof research in the USA. Proceedings of International Green Roof Congress, Nürtingen, September 14-15, 2004. pp. 107-110
Provides an overview of green roof research and application in the USA, in particular as it differs from that in Germany.
General
Brenneisen, S. 2003 The Benefits of Biodiversity from Green Roofs – Key Design Consequences. Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 10 pages
A survey of spider and beetle fauna of the new habitats on green roofs in Base, Switzerland revealed numerous endangered species listed in Red Data Books. A study of birds showed systematic use by species of grassland and riverbank habitats. Well designed roof habitats seem to represent a valuable replacement of last land habitat. Structural design of the substrate surface was the most significant factor in supporting
biodiversity. The design of green roofs should take into account the wildlife and habitat of the natural surroundings as well as the conditions of the exposed space on top of buildings.
Urban biodiversity
Brenneisen, S. 2003 Refugium für Flora und
Fauna. Garten + Landschaft 10/2003:26-29.
Describes a green roof constructed in 1914 near Zurich that supports a
variety of orchids and other rare plants. Biodiversity
Bundesverband Garten-
Landschaftsund
2002 Jahrbuch Dachbegrünung
2002, Thalacker Medien,
English title: Green Roof Yearbook 2002. This yearbook contains several articles written by leading green roof researchers. It provides a
comprehensive overview of the state of the green roof industry in 2002.
lists green roof organizations, research facilities, suppliers and contractors.
Burke, K. 2003 Green roofs and
regenerative design strategies – the Gap’s 901 Cherry project. Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 6 pages
The paper relates the issues dealt with in designing and building the grass roof at the Gap’s 901 Cherry Avenue office building in San Bruno, California from 1994 to 1997. It focuses on the role of the cost benefit study in the design approval process (e.g., a simply payback of 11 years was
estimated), and the benefits of including a native grassland specialist in the design team. Design, policy Canadian Mortgage and Housing Corporation (CMHC)
2003 Fairmount Waterfront Hotel, Vancouver, B.C. – Green Roof Herb Garden Case Study
http://www.cmhc-
schl.gc.ca/en/imquaf/himu/b uin_034.cfm
A green roof of ivy and pea gravel was initially installed in 1991. The south side of the roof was converted to an herb garden in 1994 for $25,000. The garden measures 2,100 sq.ft. with a soil depth of 18 inches, comprised of 11 beds with amended soils. Values in food production and amenities are discussed.
Urban agriculture & Community enjoyment Canadian Mortgage and Housing Corporation (CMHC)
– Merchandise Lofts Building
Green Roof Case Study
http://www.cmhc-
schl.gc.ca/en/imquaf/himu/b uin_020.cfm
Describes a green roof constructed on the Merchandise Lofts Building in Toronto, Ontario, a 12-storey mixed use (condominium, retail, commercial) complex. The green roof, seeded with a prairie meadow mix, is 10,000 sq.ft. surrounded by 15,000 sq.ft. of concrete pavers. Benefits as outdoor recreation area for tenants are discussed.
Occupant well being
Canadian Mortgage and Housing Corporation (CMHC)
– Waterfall Building Green
Roof Case Study
http://www.cmhc-
schl.gc.ca/en/imquaf/himu/b uin_019.cfm
A green roof constructed on the Waterfall Building in Vancouver, B.C. – a mixed office, retail, live-work space building – is described. The roof has both extensive and intensive elements. Benefits of neighborhood beautification, outdoor space, saleability and permitting supports are discussed.
Community benefits, marketability
Davis, K. 2002 Green Roof Inventory:
Preface Report GVRD. 61 pages
The report documents over 600 green roofs in the GVRD, the majority of which are garage and building roof decks. The City of Vancouver had the highest number among the municipalities in the Region, and the largest concentration occurred among high-rise residential developments. Ten more detailed case studies are provided. The report provides conclusions on green roof trends, performance, perceptions, and challenges and barriers in the GVRD.
sh/index
Fabry, Wolfgang 2003 These 4-3: Gründächer
senken die Kosten bei Gespaltener Abwasser- satzung. In Proceedings of the EFB-FBB* Gründach- symposium, Ditzingen, March 23, 2003. pp. 31-32
Describes the background on stormwater fees in Germany.
*EFB-FBB: Europäische Föderation der Bauwerksbegrünungsverbande – Fachvereinigung Bauwerksbegrünung e.V
Incentives – fee reduction
Fachvereinigung Bauwerksbegrünun g e.V. (FBB)
2004 Auswertung der Umfrage Dachbegrünung an Stadtverwaltungen von Städten über 10.000 Einwohner.
Survey on green roof policy by the FBB, the main green roof association in Germany, in January 2004. Out of the 1,488 cities contacted, 398 (27%) responded. However, many cities with green roof policies are not
represented. The results showed that 70 offer direct financial aid, 201 offer stormwater fee discounts, and 145 have green roof requirements in local development plans. The subsidies are often over 10 €/m² ($16 Cdn) to a stipulated maximum amount. In municipalities with split wastewater fees, green roofs typically earn a discount of between 50 and 100% on the annual stormwater fee. That is an average saving of 0.50 €/m² ($0.80 Cdn) each year for a green roof compared to a conventional roof. Available online from the FBB [www.fbb.de].
Incentives – subsidies, fees Fachvereinigung Bauwerksbegrünun g e.V. (FBB) 1997 Verankerung von Dachbegrünung im
kommunalen Baurecht durch Festsetzungen im
Bebauungsplan oder kommunale Satzungen.
This brochure describes how green roofs can be integrated into development regulations.
Regulation
Fischer, P. and Jauch, M
1999 Zur Wurzelungsfestigkeit bei Dachbgrünungen. Stadt und
Grün 11/1999. pp. 763-768
This paper describes the FLL test for determining resistance to root penetration of waterproofing membranes and root barriers. The test is conducted at certain universities around Germany.
Waterproofing Fischer, P. and Jauch, M. 2002 Dränwasser in Trinkwasserqualität? Dach + Grün 4/2002. pp. 24-31
The title of this paper is, “Drainwater in Potable Water Quality?” It shows how far along the Germans are with their research! Basically, the results of the study were that the drainwater from the tested planting medium does, apart from the colour, meet the standards for drinking water.
Design, stormwater management
Landschaftsentwic- klung
Landschaftsbau e.V. (FLL)
Bewertung in der Bauleitplanung, bei der Baugenehmigung und bei der Bauabnahme. FLL,
Bonn.
The basis of the rating system is the thickness of the green roof
construction penetrable by roots, and the ability of the particular roof design meeting minimum requirements for the following parameters:
water retention capacity of the growing medium, water retention capacity of the drainage layer,
number of plant species for extensive green roofs, and plant biomass for intensive green roofs.
The FLL system also identifies qualitative characteristics according to type of roof construction that are used to judge whether a project is suitable for ecological compensation under the Federal Nature Conservation Act. Each natural function parameter is deemed either “possible to fulfill completely”, “possible to fulfill partially”, or “slightly or not possible to fulfill.” The qualitative parameters are: soil, surface water, load shedding from the sewer system, groundwater recharge, purification of stormwater, filtering of air, oxygen production, temperature levelling, flora and fauna habitat, landscape and urban scenery, and people / leisure / healing.
Forschungsgesell- schaft Landschaftsentwic- klung Landschaftsbau e.V. (FLL) 2000 Bewertung der wertsteigernden Wirkung von Grünflächen für Immobilien. FLL, Bonn.
English title: Quantification of the Appreciation Effect of Green Spaces on
Real Estate Values – referenced in: Property value
Forschungsgesell- schaft Landschaft- sentwicklung Landschaftsbau e.V. (FLL)
2002 Richtlinie für die Planung,
Ausführung und Pflege von Dachbegrünungen. FLL,
Bonn.
English title: Guidelines for the design, construction and maintenance of
roof greening. These are the green roof guidelines “standard” in Germany
if not in Europe. Among other items, the document contains tables with runoff coefficients according to roof slope and thickness.
Design
Gedge, D. 2003 “…From Rubble to
Redstarts…”. Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 9 pages
The paper discusses the Black Redstart Action Plan – the Black Redstart being a rare breeding bird in London, England reliant on old vacant lots and brown land. The Action Plan has been a key driving force in establishing green roofs in new urban developments.
Green Roofs through Water Balance Modeling.
Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 9 pages
runoff from developed areas in the GVR. The results for 50-years
watershed retrofit scenarios shows that redevelopment of existing buildings with green roofs could effectively counteract the anticipated effects of climate change and land use densification, and also help to restore watershed health over time.
Hämmerle, Fritz 2002 Dachbegrünung rechnen
sich. In Jahrbuch Dachbegrünung 2002, Thalacker Medien, Braunschweig. pp. 18-19
This article gives some values for cost savings. Design - costs
Henz, Anke 2004 Die Bewertung
unterschiedlicher Formen der Dachbegrünung nach dem Karlsruher Modell im Rahmen der Eingriffs- regelung. In: Proceedings of the EFB-FBB Gründach- symposium, Ditzingen, March 25, 2004. pp. 30-31
Describes the performance rating system used by the City or Karlsruhe, Germany in relation to ecological compensation. The model rates how suitable a type of green roof (or other biotope) is for use as an ecological compensation measure based on five natural functions: soil, climate, flora, fauna and water balance. A comparison of performance rating systems by Zeller (2002) found that the Karlsruhe model was the most “well-rounded”.
Performance rating system
Herman, R. 2003 Green Roofs in Germany:
Yesterday, Today and Tomorrow. Proceedings of Greening Rooftops for Sustainable Communities Symposium, Chicago, 29-30 May 29-30, 2003. 5 pages
Discusses factors in the growth and development of green roofs in Germany. General Hutchinson, D.; Abrams, P.; Retzlaff, R.; and Liptan, T.
2003 Stormwater Monitoring Two Ecoroofs in Portland, Oregon, USA. Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 18 pages
Reports on a monitoring project of an apartment building in Portland, Oregon vegetated with 2 different ecoroofs. Two years of water quality monitoring and 1-year flow monitoring are reviewed. Precipitation retention and peak intensity attenuation are analyzed. Water quality benefits were more difficult to quantify.
Stormwater management
Johnston, C.; McCreary, K.; and
2004 Vancouver Public Library Green Roof Monitoring
Methods and results of monitoring a 1500 m2 (net area) green roof with
350 mm (14”) soil layer plus vegetation on the Public Library in Vancouver,
Stormwater management
Sustainable Communities, Portland, Oregon, June 2-4 , 2004. 13 pages Kohler, M.; Schmidt, M.; and Laar, M. 2003 Green Roofs as a Contribution to Reduce Urban Heat Islands.
Proceedings of RIO 3- World Climate & Energy Event, December 1-5, 2003, Rio de Janeiro, Brazil. pp. 493-498
The paper discusses the growth in measuring urban heat islands since the late 1970s. A data set of measurements from a gravel roof and two green roofs from July 2003 is used to explain some aspects of surface
temperatures in different roof substrates.
Urban heat island Mitigation
Köhler, Manfred 2004 Energetic Effects of Green
Roofs on the Urban Climate Near to the Ground and to the Building Surfaces. Proceedings of International Green Roof Congress, Nürtingen, September 14-15, 2004. pp. 72-79
Data from the research station in Neubrandenburg, Germany, is provided. Includes information on factors influencing urban climate and factors influencing stormwater retention of green roof systems.
Urban heat island mitigation
Kolb, Walter 2000 Dachbegrünung
wirtschaftlich? Stadt und
Grün 4/2000. pp. 224-227
Describes a cost-benefit analysis that takes into account the lifespan of the construction, the proportion of runoff, the effect on space conditioning, and the improvement of the living environment.
Costs Kolb, W. and
Eppel, J. 2003 Begrünung von Leichdächern – ein Systemvergleich. Teil 1 – Versuchsergebnisse aus Veithöchheim. Dach + Grün 1/2003. pp. 20-26
A comparison of six different lightweight green roof systems at a research facility in Veithöchheim. Measurements included weight, water retention, maintenance requirements, vegetation coverage, visual rating, runoff coefficients, and change in finished grade level after 3 growing seasons.
Design
Köln, Stadt 2003 Amtsblatt der Stadt Köln.
Special Publication Number 58. December 23, 2003. Stadtentwässerung- sbetriebe Köln.
This is a good example of stormwater fees and how green roofs may qualify for a reduction of these fees. In Cologne, the discount is directly
proportional to the runoff coefficient; e.g., a runoff coefficient of 0.9 means 90% of the fee must be paid; a runoff coefficient of 0.3 means only 30% must be paid.
Incentives - fees
Kortright, R. 2001 Evaluating the Potential of Green Roof Agriculture. Research project for
The report summarizes the results of a study of a green roof on Trent University’s Environmental Sciences building in Peterborough, Ontario. Fourteen common vegetable crops were planted in a 7.5 x 30 m plot
http://www.cityfarmer.org/gre enpotential.html
and at ground level. The results were then compared to each other, to the ground level results, and to official Ontario Ministry of Agriculture, Food, and Rural Affairs crop productivity statistics.
Krupka, Bernd W. 2001 Extensive Dachbegrünung.
Praxisemphelungen und Kostenbetrachtungen.
Landesinstitut für Bauwesen des Landes NRW, Aachen.
English title: Extensive Roof Greening: Recommendations and Cost
Considerations. This publication contains very detailed information on
costs. Chapter A contains recommendations on design and implementation of green roofs. Chapter B is on aspects of stormwater management. Chapter C contains detailed building costs on 10 existing extensive green roofs. Because the costs were difficult to compare, price quotes for a sample green roof project were requested from 50 green roof
companies/contractors and these average costs are also provided. In Chapter D, several calculations are shown comparing gravel ballast roofs with extensive green roofs (multi-layer and single layer) over a 40-year lifespan. Some of the factors are whether or not stormwater fees are included and different investment models.
Design - costs
Krupka, Bernd W. 2004 Potenzielle Fehlerquellen bei Dachbegrünung und deren Vermeidung. Proceedings International Green Roof Congress, Nürtingen, September 14-15, 2004. pp. 136-142
Reviews the potential sources of green roof failures, especially those that relate to vegetation, and recommends how to avoid them. Frequent problems cited are:
damages to the substrate layer and vegetation caused by wind or water erosion,
insufficient initial planting,
defects in coverage of the green roof vegetation, pest infestation,
waterlogging,
imperfection of the substrate layer and the green roof build-up, and
poor maintenance.
Design
Kuhn, M.; Lui, K.K.Y.; Marshall, S.
2001 Green Roof Infrastructure Workshop Proceedings, June 25, 2001. 34 pages
The workshop was designed to provide architects, researchers and policy makers with an introduction to the benefits, development and design of green roofs and an overview of current research projects, needs and opportunities.
General
Lando, P. 2004 Test Plots for a Light Weight,
Low-cost, Vegetative Roof in Commercial Applications. Proceedings of Greening Rooftops for Sustainable
The project consists of 8 test plots in Portland, Oregon with varying configurations of growth media and drainage. The project is designed to examine propagation methodology, plant material, irrigation regime and maintenance costs of “bare essentials” approaches. The project concluded its first year of results and is intended to continue for the next 4 years.
Liesecke, Hans-
Joachim 2002 Ergebnisse eines Langzeitversuches zur extensiven Dachbegrünung. Teil 1, Dach + Grün 11: 4/2002. pp. 10-17
Results from a long-term study on extensive green roofs. Part 1 provides data on substrate development, thickness, load-bearing capacity and water retention. The paper also discusses the research program.
Stormwater management
Liesecke, Hans-
Joachim 2003 Ergebnisse eines Langzeitversuches zur extensiven Dachbegrünung. Teil 2, Dach + Grün 12: 1/2003. pp. 4-10
Results from a long-term study on extensive green roofs, part 2 provides
data on vegetation coverage and vegetation groupings and combinations. Stormwater management
Lietke, Dirck 2003 These 4-1: Gründächer sind
wirtschaftlich und lassen sich rechnen. In: Proceedings of the EFB-FBB* Gründach- symposium, Ditzingen, March 23, 2003. pp. 29-30
The author presents cost savings for a green roof on a sample industrial building.
Costs
Liu, K. and Baskaran, B.
2003 Thermal Performance of Green Roofs through Field Evaluation. Proceedings of Greening Rooftops for Sustainable Communities, Chicago, 2003. 10 pages
The National Research Council constructed a field roof facility on its Ottawa campus to measure the thermal performance of a generic extensive green roof with 150 mm of growing medium and a reference (modified bituminous) roof. The green roof reduced temperature and daily temperature fluctuation of the roof membrane significantly in spring and summer, as well as
moderated heat flow into the building. The green roof was more effective in reducing heat gain than heat loss.
Thermal insulation/ energy reduction
MacMillan, G. 2004 York University Rooftop
Garden Stormwater Quantity and Quality Performance Monitoring Report. Proceedings Greening Rooftops for Sustainable Communities, Portland, Oregon, June 2-4, 2004. 14 pages
Monitoring results of a green roof on York University’s computer science building in Toronto are presented. The 241 m2 roof garden has a 10% slope and 140 mm substrate. A 131 m2 shingle roof was used as a control. Monitoring occurred from May-November 2003. Reductions in rainfall runoff and peak flows, lag times, and runoff coefficients are discussed.
Stormwater management
Commerce Online,
September 27, 2004 issue. 4 pages
Mainz, Christof 2004 Förderungen der
Dachbegrünung. In:
Proceedings of the EFB-FBB Gründachsymposium, Ditzingen, March 25, 2004. pp. 16-17
Discusses the stormwater source control subsidy program in North Rhine, Westphalia.
Incentives – subsidies
Mann, Gunter 1999 Begrünte Dächer als
Lebensraum. Stadt und Grün 5/1999. Pp. 328-333
This article presents the results of a survey of soil organisms on 125 green roofs. It follows with design recommendations on how to encourage soil fauna.
Urban biodiversity Mann, G.; Uhl, M.,
and Schiedt, L. 2000 Wasserhaushalt auf begrünten Dächern. Stadt
und Grün 4/2000. pp. 246-
254
A model is presented for simulating the water balance on green roofs. The model is based on results from the research facility in Krauchenweis, Germany.
Stormwater management
Mann, Gunter 2000 Retentionsverhalten
begrünter Dächer: In Abhängigketi von der Niederschlagsrevion. Stadt
und Grün 10/2000. pp. 681-
686
There is a table in this article that gives a good overview of the German research into stormwater retention and runoff coefficients for green roofs. Otherwise the article is about a stormwater simulation program.
Stormwater management
Marx, I. and
Kolb, W. 2002 Mineralische Zusätze für Einschichtsubstrate in Dachbegrünungen. Dach +
Grün 1/2002. pp. 23-28
This paper describes the testing of different planting medium amendments used to clarify water draining off green roofs. Three amendments are clay, zeolite and activated carbon.
Design, stormwater management.
Landeshauptstadt Linz (Oberösterreich). In
Proceedings of the EFB-FBB Gründachsymposium, Ditzingen, March 25, 2004. pp. 12-15 McCarthy, S. and McCullough, S.G. 2004 Milwaukee Metropolitan Sewerage District Extensive Green Roof. Proceedings of Greening Rooftops for Sustainable Communities, Portland, Oregon, June 2-4, 2004. 8 pages
The MMSD installed the first green roof in the Milwaukee area in July 2003. The primary purpose was to demonstrate the ability of green roofs to reduce stormwater runoff, and to set an example for other public agencies and private owners to install green roof systems. A Green Grid system was used. Stormwater monitoring infrastructure was installed but no data reported as yet.
Stormwater management
Michels, Kurt 2004 Norm- und regelgerechte
Abdichtungen für Dächer mit Begrünung. Proceedings International Green Roof Congress, Nürtingen. pp. September 14-15, 2004. pp. 111-118
Contains information on standards for green roof waterproofing materials. Discusses the different kinds of stresses on waterproofing such as root growth, moisture, mechanical stress, thermal stress, fire prevention and protection against wind uplift. References to German norms, standards and guidelines are provided.
Waterproofing
Moran, A.; Hunt, B.;