Portland is once again accepting applications for ecoroof incentives. The city started giving out $5 per square-foot grants for new ecoroofs in 2008 primarily to reduce stormwater runoff. But the program also kick-started a growing industry.
There are now more than 100 companies that offer ecoroof services in Portland. And according to this story in Sustainable Business Oregon, as the industry has grown the average cost of building an ecoroof has dropped from $16-$20 per square foot in 2008 to $9-$12 this year. That's still not on par with conventional roofing, but to be fair, regular roofs don't offer the same benefits.
Ecoroofs are basically just plants growing on a roof lined with a plastic membrane. But they serve several useful purposes, including: absorbing rainwater, providing insulation for the building to help conserve energy, offering habitat for wildlife, absorbing carbon dioxide, and lowering urban air temperatures.
So far, the city of Portland has given out $2.4 million for 145 projects that make up 11 acres of new ecoroof. The city's Grey to Green initiative sets a target of 43 acres of new ecoroofs by 2013 that would divert 17.6 million gallons of precipitation from the city's stormwater system.
How many total acres of ecoroofing are in Portland now? A good trivia question if I ever heard one. According to the city, there are now 300 ecoroofs in Portland covering nearly 15 acres.
Do you have an eco-roof? Tell me about it! Was it hard to build? Has it reduced your utility bills?