“The green roof industry grew by 115 per cent over the course of 2011, up significantly from 28.5 per cent growth recorded in 2010,” said Steven W. Peck, president of Green Roofs for Healthy Cities.
“We are definitely beginning to see results from policy support that has increased over the past few years,” said GRHC chairperson Jeffrey L. Bruce. Toronto, for example, introduced its Green Roof bylaw and Eco-Roof Incentive program in 2009. Most major cities throughout North America have similar programs.
So why the push by municipalities to encourage/direct greater green roof construction? A sampling of benefits include:
- Stormwater management.
- Increase of biodiversity.
- Moderation of heat island effect.
- Improvement of air quality.
- Improvement of esthetics.
- Local job creation.
- Addition of new amenity spaces.
In the most recent GRHC survey, Washington, D.C., led all major cities in North American green roof construction in 2011, adding more than 800,000 square feet. Canada is well represented in the year’s survey, with three cities (Toronto, Montreal and Quebec City) joining Washington, Chicago, New York, Nashville, Philadelphia, Kansas City and Seattle in the top-10 rankings. (Just outside the top-10 listings were Vancouver and Halifax.) There was a little more than 16 million square feet of green roofs installed in North america in 2011, well up from the million or so recorded in 2004. The trend is clear.
GRHC members worked on 870 projects in 2011, well up from the 713 projects completed in 2010. In total, some 7,577,935 square feet was installed in 2010, up from 4,341,394 installed in 2009. “It is difficult to know what the total square feet installed in North America is each year, due to the fact that not all GRHC members participate in the survey, and that some projects are designed and constructed by non-members. Hence, the number of green roofs reported falls significantly short of the actual number completed,” note the survey authors.
Canada is becoming a world leader in green roof research, with programs underway at the University of Guelph and Niagara College in Ontario, along with the British Columbia Institute of Technology, among others.
Researchers and politicians/planners are increasingly supporting the green roof concept. Growers would do well to follow their lead. Someone has to supply those plants.