STATE COLLEGE — The public can’t access it, and can’t even see it from the ground, but climbing out a third-floor office window at the municipal building gives a breezy view of South Allen Street and the borough’s green roof, now taking on its fall colors.
The concept was proposed in 2009 and executed in 2010, transforming the roof over the second-floor community room into a garden space to help the borough meet its sustainability goals.
Environmental Coordinator Alan Sam said he hasn’t taken the time to quantify the benefits of the 1,400-square-foot project, but some of those are reducing stormwater runoff, reducing pollution through stormwater filtration through the soil, reducing building heating and cooling costs and reducing the heat island effect, which is when an urban area heats up more than surrounding rural areas due to activity there.
Based on a green roof demonstration project in Portland, Ore., Sam estimated that the borough’s plantings could reduce runoff by about 33,000 gallons per year.
“We wanted to see the feasibility, if we’re going to encourage developers to do it,” Sam said. “I think this would be feasible for new construction. It does protect the roof material.”
The new planned commercial zoning district (CP3) approved this spring includes a green roof as an incentive. Should developers include one in their plans, they can get a 5 percent residential density bonus and a 10 percent reduction in required parking.
The project was funded mostly through grants — $25,000 from the state Department of Community and Economic Development and $79,674 from the federal American Recovery and Reinvestment Act program. Less than 20 percent was paid through borough funds.
Part of what increased the cost was that the ceiling of the community room needed additional beams installed as reinforcements to ensure it would handle the weight of the soil, plants and absorbed precipitation.
The plants were grown off-site in square modules, and a crane was used to install them on the roof. Those plants are low-growing sedums, succulents that Sam said are low-maintenance, basically requiring just weeding and fertilizing.
“They’re so easy,” said Courtney Hayden, the borough’s communications coordinator. She started as an AmeriCorps worker for the borough, and the green roof was one of her first projects. “I like when it flowers. It does have some seasonality to it.”
“It’s built awareness on our own (authorities, boards and commissions) and staff,” Sam said.
— Jessica VanderKolk