Panel approves one-year extension to study green roofs

The Design Commission supported a year-long extension to the city’s green roof advisory group last night, a vote intended to give a committee more time to grapple with incentives that could benefit green roof users.

 

Eleanor McKinney, former long-time Design Commission member, chairs the Green Roof Advisory Group. Matt Hollon of the Watershed Protection Department and Maureen Scanlon of the Austin Energy Green Building Committee joined McKinney in her presentation.

 

Landscape architect McKinney described Austin as having made some progress but still lagging behind other major cities. Currently, Austin would be considered Stage III on the green roof scale, just beyond the public input process. By comparison, Stuttgart, Germany is Stage VI, already actively engaged in requiring green roofs everywhere, including both commercial and residential buildings.

 

However, McKinney admitted her group had no data on the benefits of green roofs in Austin versus the drawbacks.

 

The incentive to use green roofs in Austin, especially in downtown Austin, is at least two-fold. First, it cuts down on the heat island effect. And, second, it might alleviate city code provisions in areas such as pervious cover or water detention.

 

Already, the group is looking at zoning benefits for those who use of green roofs. Putting greenery on the tops of buildings downtown could prove four-fold benefits to developers, meeting requirements for landscaping, open space, green building and, possibly, even water quality/detention ponds, Hollon said.

 

Asked to calculate the cost of green roofs versus their benefits, McKinney and her committee members were at a loss. McKinney admitted her group had focused on only one side of the equation, although she invited members of the Design Commission to participate in doing some type of cost-benefit analysis.

 

Commissioner James Shieh, in particular, wanted to make sure that participants in any waiver or incentive package continued to maintain their green space. Hollon said that was especially important if the roof was being used to meet detention requirements, requiring long-term maintenance of green space.

 

The group strongly supports green roofs as an incentive within the downtown density bonus. Short term, the committee wants to develop some performance standards for green roofs, determining what size and scope should get credit, Scanlon said. Issues such as size, scope, water use and drainage should be considered.

 

Commissioner Richard Weiss suggested the possibility of interim regulations during the additional year of study, but that did not appear to be the best option, according to Hollon. The commission went on to approve a one-year extension.