The Denver City Council voted unanimously to repeal and replace the green roof requirement that voters had enacted a year ago.
The new law requires light-colored cool roofs on new and re-roofed buildings of more than 25,000 sf. If widely used, cool roofs can lower urban temperatures by several degrees.
The city estimated that the original green roof law could have added $193,000, or about 2.8% to the cost of a five-story office building. The new law could cut that increase in half, with significantly higher savings for some buildings.
Building owners also will have to choose among the following environmental options: installing green space, funding it elsewhere, meeting green design standards, or installing renewable energy. Apartment buildings fewer than six floors will be exempted from this provision.