Photo courtesy of the American Society of Landscape Architects (ASLA). Visit asla.org/greenroof for more information.
Green roofs have been steadily gaining in popularity since 2004. The biggest jump happened just last year when the North American green roof industry grew by an estimated 115%, according to a study by Green Roofs for Healthy Cities.
It’s estimated that at least 16 million square feet of green roof space was installed in 2011. Just 4.3 million square feet was installed in 2009.
There is a fairly even split between private and public green roof installation.
Hot metro markets. From 2004-2011, the 10 hottest metro markets in North America were:
- Chicago (more than 3.5 million square feet)
- Washington, D.C. (roughly 2.75 million)
- New York City (nearly 1.5 million)
- Toronto (roughly 0.75 million)
- Vancouver (just over 0.5 million)
- Baltimore (right around 0.5 million)
- Philadelphia, Ottawa, Milwaukee, Kansas City, Quebec, Montreal, Nashville, Seattle and Cincinnati all saw less than 0.5 million square feet installed.
The hottest metro markets in 2011 were:
- Washington, D.C. (roughly 850,000 square feet)
- Chicago (more than 650,000)
- New York City (just over 300,000)
- Nashville (around 300,000)
- Philadelphia (over 250,000)
- Kansas City (just under 200,000)
- Seattle (just under 200,000)
- Syracuse (roughly 133,000)
- Omaha/Lincoln (roughly 133,000)
- Milwaukee (roughly 133,000)
Government incentives. Arguably the biggest factor behind growth in green roof installation is green infrastructure policy of local government. Several have emerged over the past several years, including:
- Portland Ecoroof Incentive – 2005
- Minneapolis Stormwater Utility Fee Credit – 2005
- Chicago Green Permit Program – 2006
- Washington, D.C. Green Roof Rebate Program – 2007
- Philadelphia Green Roof Tax Credits – 2007
- Anne Arundel County (MD) Stormwater Management Tax Credit – 2008
- State of New York Green Building Construction Act – 2009
- Toronto Green Roof Bylaw and Eco-Roof Incentive Program – 2009
- Onondaga County (Syracuse, NY) Green Improvement Fund – 2010
- Milwaukee Metropolitan Sewerage District Regional Green Roof Initiative – 2010
- Austin (TX) Green Roof Density Bonus – 2011
Future growth. Green Roofs for Healthy Cities says the future growth potential for green roofs is enormous.
There are billions of rooftop square feet in North America that present opportunity for green roof installation.
There are numerous large metro markets that have yet to establish policies and/or incentives to encourage green roof installation.
The Green Roof Professional (GRP) accreditation program is also becoming more popular. There are more than 500 GRPs across North America today. This high level of education and discipline helps bolster consumer confidence in green roofs.
Benefits of green roofs. According to Green Roofs for Healthy Cities, there are numerous environmental benefits to having a green roof system on your building:
- Stormwater management
- Increase of biodiversity
- Moderation of urban head island effect
- Improvement of air quality
- Improvement of aesthetics in the public realm
- Addition of new amenity spaces
- Local job creation