“Green roofs” become “cool roofs”
The Denver City Council on Monday night voted unanimously to repeal and replace the “green roof” requirement that voters had established a year earlier.
The original law would have required rooftop vegetation for large buildings, but the council decided to give developers more options for achieving environmental goals.
Under the new law, the city will require “cool roofs” on new and reroofed buildings of more than 25,000 square feet. Such lightcolored, reflec tive roofs already are popular in Denver. In large numbers, they can lower urban temperatures by several degrees, researchers said.
Building owners also will have to choose among the following options: installing green space, funding it elsewhere, meeting green design standards or installing renewable energy. (Apartment buildings fewer than six floors are exempted from this part.)
The original greenroof law passed with 54 percent of the vote last November, despite bigmoney opposition. Brandon Rietheimer, a key organizer, now supports the revision. Ac tivists, developers and city officials “worked tirelessly to come to a compromise,” he said.
“Brandon Rietheimer, thank you for kicking the door open,” said Councilman Paul Kashmann, calling it a move “farther into the 21st century.”
In contrast, Kyle Zeppelin, a developer who has embraced the costlier green roof, said that the change sacrificed the water and air benefits that rooftop gardens can provide.
“There clearly needs to be a lot more permeable landscape throughout the city, and this was the opportunity to push some of that burden off on developers who are making money hand over fist,” he said in an interview.
City research found that the original green roof law could have added $193,000, or about 2.8 percent, to the cost of a fivestory office building.
The revision could cut that increase in half, and the savings were significantly steeper for some buildings.
The new “cool roof” mandate faced opposition from some roofing manufacturers, but others in the industry supported it. Councilman Chris Herndon was not present.