A consultant hired by the City of Denver to investigate compliance with the Green Roof Initiative told Denver City Council members on Monday, April 2, that it will help the city attain its 2020 Sustainability Goals. The not-so-good news? Representatives of city agencies said that if the initiative, which 54 percent of voters approved in November, is implemented without changes, it presents challenges with potential unintended consequences.

The initiative requires new buildings of 25,000 square feet or more to include green roofs, which help filter air and reduce temperatures both inside and outside the buildings; existing buildings of 25,000 square feet or more that redo their roofs will have to include vegetation and solar panels. Builders can ask for an exemption from the Denver Planning Board that, if granted, will require a fee-in-lieu.

After the initiative passed, the city formed a task force that includes representatives of the real estate industry, the initiative's author and other backers, and a few city council members to clarify and possibly amend its requirements. The task force will meet through May, start taking public comments, then present its findings to the complete council. Any amendments would require a two-thirds majority vote from council.

Jill Jennings Golich with Community Planning and Development, the city department that oversees planning and sustainable building, laid out the initiative's challenges for some councilmembers at an April 2 meeting. She maintained that Denver's Green Roof Initiative, one of the most stringent in North America, pulled language directly from a similar policy in Toronto and "didn't think through the unique challenges" in this city. For example, the initiative defines some terms differently than does the City of Denver; requires roofs to retain a certain amount of water, which is inconsistent with state law; conflicts with fire code; and charges the wrong city department, the Planning Board, to consider building code.

Katrina Managan with Denver's Department of Public Health and Environment said the private sector is approaching the Green Roof Initiative with trepidation; owners are delaying replacing roofs of existing buildings because of the learning curve that green roofs and solar panels presents to many builders. She estimated that as many as 90 percent of Denver's existing buildings couldn't support the load of green roofs, meaning they are likely to get an exemption.

District 4 councilwoman Kendra Black, who represents southeast Denver, said that affordable-housing developers in her district are concerned that the initiative's requirements would increase construction costs so drastically that they would impact rent prices.

Managan offered examples of different buildings and their requirements under the initiative to illustrate potential construction costs. According to city estimates, an existing 55,000-square-foot apartment building would see a 68 percent to 102 percent increase in construction costs to implement the required 30 percent vegetation and solar-panel roof coverage. Green roofs might drain more money than they add for buildings because of maintenance costs, she added; however, solar panels could actually save buildings money.

The task force is considering the city's findings and could amend the initiative so that it stays true to its intent but varies some requirements, according to Councilwoman Mary Beth Susman, a member of the task force. "It's not about the green roof, but it's about the goals," she said during the meeting.

For example, the initiative could eventually look more like Chicago's, which offers a variety of options for builders, including cool roofs, which reflect sunlight and absorb less heat than traditional roofs, or allowing buildings to enroll in other energy-efficient programs. Denver's initiative could also be changed to take into consideration emergency situations in which a building must quickly replace its roof, such as after a hailstorm.

Councilman Rafael Espinoza said he was hopeful that the initiative would do more good than harm, and commended the task force for including the initiative's backers.

"The seeds are there to get us back on our sustainability goals," he said.

