August 25, 2014 | By Zach Despart
MIDDLEBURY — Gazing east from the Kenyon Lounge on the campus of Middlebury College, there’s a wonderful view — the campus’ sprawling athletic fields, golf course and Green Mountains in the distance.
That view just got a lot better, thanks to the installation last week of a new green roof on the school’s squash center, which opened last fall.
The green roof, also called a living roof, features growing plants set in a soil medium on top of a waterproof membrane installed on top of the building’s roof. It was constructed by LiveRoof Global, a company based in Michigan.
In addition to adding to the building’s natural beauty and other environmental benefits, LiveRoof representative Ben Lucas said a primary benefit of green roofs is they mitigate stormwater runoff.
“During large rain events on a roof that doesn’t have plants on it, water rushes down the drains as quickly as possible, then into rivers and streams,” Lucas said. “The water has all sorts of contaminants you find on the roof that you don’t want in your water.”
Lucas said green roofs capture a lot of that water, decreasing runoff. Green roofs also serve as insulation, keeping buildings cool in the summer and warm in the winter, and provide a habitat for small birds and insects.
Mark Gleason, project manager with the college’s Facilities Services Office, said the roof is another step the institution is taking to become more environmentally conscious.
“It continues the environmental mission and tries to minimize the impact of a new building on the landscape,” Gleason said of the squash center.
Gleason expects the building to earn a Leadership in Energy and Environmental Design (LEED) certification from the U.S. Green Building Council, which rates structures based on a litany of criteria.
Integral to the LEED certification application was the use of a light membrane roof, which refracts heat instead of absorbing it. The plants that form the green roof protect the membrane.
“But putting a green roof on top of waterproofing, it’s in essence protecting it, thus extending its life two or threefold,” Lucas said. “They won’t have to replace this roof membrane for 60 to 70 years.”
LiveRoof Global contracts with 20 growers around the country, the goal being that plants aren’t grown far from where they are planted on green roofs. The plants for Middlebury’s new green roof, which are several varieties of sedum, were grown at a nursery in Connecticut and then shipped to Vermont.
Lucas said sedum is an ideal plant for green roofs because it can thrive in a variety of conditions and does not require much attention. They are also perennial, meaning they will go dormant during the harsh Vermont winter and blossom again in the spring.
“Sedum are neat plants because they love full sun, but don’t need a lot of water,” Lucas said. “In essence, they’re like cactus.”
The roof itself requires little maintenance. Lucas said just one worker is needed during the growing season, to pick weeds that compete with the sedum.
“Especially with tree seeds, those can actually go down and penetrate the waterproofing, creating a leak in the building,” Lucas said.
Lucas said Middlebury’s choice to install a green roof is part of a national trend in the United States.
“I think we are seeing the advent of green technology and green roofing, which to us in the U.S. is quite a new thing over the last 10 years,” Lucas said. “Since it originated in Europe, the trends we see are upward.”
This is the second green roof on campus. The first, atop the Atwater dining hall, was built in 2003. Gleason said the college is always looking to lessen its environmental footprint, though it does not necessarily mean more green roofs in the future.
“It’s on a case-by-case basis; a lot of roofs don’t warrant a green roof, especially ones that are peaked,” Gleason said. “We don’t have plans for more green roofs or buildings, but it’s always a factor during the decisions around construction.”
The college does reap benefits from the green roof that aren’t related to the environment. Gleason said varsity coaches often take recruits up to the Kenyon Lounge, and the school wanted to preserve the beautiful views from the balcony by installing a green roof.
“The green roof is a much better aesthetic than the membrane roof,” Gleason said. “The Kenyon Lounge is an important reception room in the athletics complex, and it was important not to lose that aesthetic.”
Lucas said green roofing costs about $30 per square foot. The squash center roof is about 14,500 square feet. Using those numbers, the estimated cost would be $435,000.
Boston-based firm Apex Construction and Design performed the labor, which took about a week and was expected to be complete by Friday.
Gleason said there isn’t really a return on investment for a green roof. Rather, he framed the college’s benefit as decreasing its impact on the environment.
“You don’t do it to save money,” Gleason said. “I think there are benefits beyond the dollars.”
LiveRoof’s Lucas said the impetus for the project was Middlebury College’s commitment to environmental sustainability.
“It really starts with Middlebury’s mindset and initiative to be a greener campus,” Lucas said. “The real vision is coming from guys like Mark. Their goal is to make each new construction project have some sort of environmentally conscious building design built into the building itself.”