Gardens are topping a growing number of Philly homes.
Record heat, rising energy costs and signs the construction boom is waning are all around us this summer. But one remedy is gaining prominence among Philadelphia homeowners and developers alike: green-roof technology.
Green roofs generally consist of layers of protective membrane, stone aggregate and soil with the ability to support vegetation. They've been popular in Europe for nearly two decades, and began popping up in lightweight form in the U.S. about 10 years ago.
More recently, green roofs have been installed on commercial structures. Chicago, and lately New York, are frontrunners in the green-roof movement. (A New York Times piece two weeks ago found residents there are now willing to pay more to live in eco-friendly buildings.) And according to some local developers, Philadelphia's not far behind.
The concept behind green roofs is simple: Increasing the amount of urban open space and greenery leads to numerous environmental benefits. In many cases the roofs increase property values and save big bucks on energy bills.
"Everybody is concerned about the bottom line, so we just explain to them that your bottom line makes sense, and people are accepting that," says Tim McDonald, a local architect and contractor. Last year he and his brothers Patrick and Johnny, along with partner Howard Steinberg, formed JIG Inc. The company already has 95 green-roofed residential units on the boards in Fishtown and Northern Liberties.
"I can guarantee you that if Philadelphia has 95 units out of one company in the next two years, Philadelphia's going to start to be known for green roofs," says McDonald, whose brother Patrick first took interest in the technology several years ago. "On top of that, other companies are going to start popping up. We hope we get a lot of competition."
Green-roof advocates say the technology helps improve the city's air and water quality, while reducing the potential for flooding and maintaining more comfortable temperatures inside the buildings they top. For these reasons, the Philadelphia Zoning Board of Adjustment has granted variances that recognize green roofs as pervious surfaces-which makes it easier for developers to meet zoning requirements in tight urban spaces.
"With all the new development, the city has an increased burden on its storm water and sewer system. All this rainwater [runoff] has to be processed," explains Steinberg.
He and McDonald also run the architectural firm Plumbob LLC, which designs most of JIG's projects.
"The green roof actually holds that water and uses it for irrigation for the greenery, whether you're growing plants or grass, so it's a benefit to the city system to retain that," Steinberg says. "Plus it protects the actual roof from the UV breakdown, so the longevity of the roof membrane is extended-probably doubled at least."
But less maintenance is just one way green roofs save money. They can also provide an added layer of insulation-particularly from summer heat. The roofs also mitigate effects of the "heat island" that's created in cities when concrete and blacktop absorb heat.
Mark Masters, founder of the Fencing Academy of Philadelphia, can personally vouch for the benefits of green roofs. His apartment overlooks the Academy's rooftop, which, at 5,000 square feet, is the second oldest large green roof in the nation.
|Plant it right here: Fencing Academy of Philadelphia founder Mark Masters' apartment overlooks the nation's second-oldest large green roof.|
Masters boasts about having a backyard in the city that never needs mowing. "And hospitals have found patients who overlook the park get better faster than those who overlook the parking structure," he notes. "There are health benefits."
Masters' roof was built 10 years ago by engineer Charlie Miller. His company Roofscapes operates out of Mt. Airy and was one of the first to bring lightweight green-roof technology to the United States.
Miller also helped train the JIG team get licensed in green-roof construction. He primarily develops large-scale commercial green roofs, such as his design on top of Chicago's City Hall in 2000, but he says interest in all areas of the technology has picked up considerably in recent years.
"It takes a while for a new idea to gain currency and for people to feel comfortable discussing it," says Miller. "There's nothing novel about the idea of city greening in Philadelphia, but the actual implementation of lightweight German-style green roofs just in the last two years has really had a significant grasp on people's imaginations."
On top of that, Miller points out the city recently published new storm water regulations that'll likely increase incentives for green-roof construction.
"Philadelphia, in particular, is one of the easiest cities to do it," adds Miller. "A lot of the older buildings in the city have very heavy roof structures. They were designed at a time when builders waterproofed roofs by putting up thick layers of coal, tar and fabric, which was quite heavy."