May 8, 2006

Ottawa makes top ten list of North American green roof cities

Ottawa was the sole Canadian city out of the top ten in North America in terms of square footage of green roofs planted during 2004 and 2005. A survey conducted for the green roof industry also reported a 72% growth in the total area of green roofs planted across North America between 2004 and 2005, with the increase exceeding 80% in the U.S.

The total square footage rose from 1.3 million in 2004 to 2.5 million in 2005, says Green Roofs for Healthy Cities (GRHC), a Toronto-based non-profit group representing companies involved in green roof infrastructure. The survey was carried out by an indpendent group, Kendon Light.

GRHC notes that the actual figure is in fact higher than that indicated by the survey for two reasons: first, the survey data do not reflect all of the association members's projects; and second, GRHC members do not currently represent the entire green roof industry.

The survey, the first of its kind for the industry, ranked the top ten North American cities by square footage planted in 2004 and 2005. Ottawa was second only to Chicago in 2004, with 120,000 square feet of green roofs planted, but fell to tenth place in 2005, with only 84,600 square feet. Chigaco ranked first in both years, with Washington DC rising from third place in 2004 to second in 2005. GRHC notes that these jurisdictions, along with Virginia (which had three cities in the top ten), have policies and programs in place to support green roof implementation.

The survey findings indicate that the green roof industry is off to a strong start, and provide an important baseline from which to gauge future progress, says GRHC.

Green roof infrastructure involves the use of technologies incorporating drainage systems, high-quality waterproofing, a root-repellant layer, specialized growing media and specially selected plants to create vegetated areas on building rooftops. Benefits include reduced stormwater runoff, better heat and sound insulation, energy savings, improved air quality and a reduction in the urban heat island.

More information is available from GRHC, 416/971-4494, FAX 416/971-9844, Web site www.greenroofs.org.

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