Target Center green roof project moving forward 2 Comments UPDATED February 28, 2008, 4:21pm

By Steve Pease

The idea of a green roof at Target Center apparently grew quickly on city officials.

City Council Member Lisa Goodman (7th Ward) said today that the 18-year-old Target Center will have a green roof, after all.

“We can say for an absolute fact we will have a green roof on the Target Center,” Goodman said at Committee of the Whole meeting. “Through a lot of good work by [Community Planning and Economic Development] CPED staff, we’re actually going out for bid on green-roof options.”

Goodman said there are three options for the 100,000 square-foot-roof:
• A 20,000-square-foot green roof;
• A 100,000-square-foot green roof; and
• What Goodman called the “preferred option” of a higher-intensity 20,000-square-foot exterior green roof and an 80,000-square foot interior green roof.

The decision to go green may surprise some.

In 2006, Kandiyohi Development Partners said the instillation of a retrofitted green roof system on Target Center might reduce the temperatures Downtown and benefit storm water runoff management. Additionally, Kandiyohi said that a green roof would last longer than a traditional tar roof.

However, a Dec. 11, 2007 memo prepared by CPED determined that a green roof on the Target Center would “not be feasible.” The report stated that the a combined city staff and Target Center management AEG report concluded that a new roof could not exceed the existing roof weight of 13.4 pounds-per-square-foot in order to maintain structural capacity and support lighting and sound equipment.

Furthermore, the Target Center’s longtime city architecture and engineering firm, Leo A Daly Co. said the “lightest single source green roof systems weighs approximately 17.1 ppsf," according to the CPED report.

“This change would be done anyway,” she said. “The useful life of building’s existing roof is over. We’re doing it because the roof needs replacement.”

Goodman said the project is currently out for bids, but did not say how, when and where it would be paid for. In the December report, CPED said a conventional roof would be $2 million. Roof construction was anticipated to begin in April 2008, with completion sometime this summer, according to the report.

Goodman said a green roof would last 40 years, while a conventional tar roof would last half that. The roof was nearing the end of its 15-to-20-year lifespan.

“This is a situation where we really took a lemon and made lemonade out of it,” she said. “[Target Center] is not the most beautiful, doesn’t have curb appeal.”

Once installed, and depending on the option, the Target Center’s green roof would make it the second largest green roof installation in the country next to Dearborn, Mich.’s 10.4-acre Ford Dearborn Truck Assembly Plant, Goodman said.

Goodman called the move a major victory, and major step forward.

Goodman thanked Council Members Paul Ostrow (1st Ward) and Cam Gordon (2nd Ward) and called the move a major victory and step forward.