Learning from Green Roofs: A Bronx School's Lesson in Saving Energy

Article excerpt

Standing on the rooftop at St. Simon Stock Catholic School on East 182nd Street in the Bronx, i New York, Daniel Simon, marketing director of the Gaia Institute, points to a neighboring high-rise apartment building. A couple is looking down from a high window over the rooftop garden. "Those people have been living here a long time," says Simon, "and one day they had a green roof to look at instead of city construction."

Green roofs are usually flat, and partially or completely covered by soil and plants. Germany and Japan have incorporated them into building projects for many years, and they are now becoming popular in eco-minded cities in the U.S. According to the Green Roofs Institute, total coverage in North America climbed from 1.3 to 2.5 million square feet between 2004 and 2005. Green roofs lower cooling bills, provide research opportunity and bring the natural world to inner-city children. "The green roof movement is growing rapidly here," says Leslie Hoffman of Earth Pledge's Green Roofs Initiative.

Simon, with Gaia Institute founder Paul Mankiewicz, pushed the Bronx project to completion in June 2005. The roof is a lone patch of green in the quilt of gray, beige and black that stretches across the southeast Bronx. Six inches of a patented, lightweight growing medium called Gaia Soil covers 3,500 square feet, divided into plots for both elementary and graduate school research. The roof hosts 20 native species: delicate columbine flowers, milkweed that attracts migrating Monarch butterflies, tomato and cucumber plants, and black-eyed susans, favored by bumblebees. "You can see some pollination here," says Simon, "which is rare because there aren't a lot of plants in the Bronx to pollinate."

Parish rector Nelson Belizario was struck by the roof idea when he arrived at the school two years ago. "I looked out at the rooftop and knew we needed gardens here," he says. Belizario learned about green roofs in Chicago, where Mayor Richard Daley's administration requires any city-funded project to meet Leadership in Energy and Environmental Design (LEED) Certification.

Belizario got in touch with Mankiewicz, who played matchmaker between the school and the borough. The result was an award totaling more than $130,000 from the Bronx Overall Economic Development Corporation (BOEDC). "We're quite excited about St. Simons as a model for what's possible with a green roof," says Kate Shackford, director of the BOEDC'S Initiative for Energy and the Environment. "We'd like to see more green roofs in the Bronx."

Mankiewicz estimates that the Bronx has 10 green roofs, including the municipal courthouse across the street from Yankee Stadium. Weight, apart from cost, is the largest obstacle to building more green roofs. "A lower weight soil is important because of the load-bearing limits on rooftops. For existing structures, lighter-weight soil means less restructuring," Simon explains. …