Green roof keeps house cool, dry

Workers installing a green roof on Majora Carter’s and James Chase’s home in Hunts Point put down drainage plates to prepare for planting.

From the street, the red-brick, two-story rowhouse on Manida Street looks as typical as they come. But instead of tar or tile, its roof is covered with plants. It boasts the Bronx’s first-ever green roof on a single-family home.

The home belongs to Majora Carter, the executive director of the environmental justice group Sustainable South Bronx, and her husband, the organization’s communications director, James Chase. They and their organization have helped put Hunts Point at the center of a new environmental movement aimed not only at conserving energy and cleaning up the air and waterways, but at relieving the burden on poor communities and creating jobs for local residents.

Although a late snowfall hid the roof on a recent visit, photographs taken when it was installed in the fall show patches of bright flowers surrounded by tiny sprouts of sedum–a hardy, green, low-growing plant whose leaves store water. The plants were all grounded in a flat layer of neat soil that covered 850 square feet of the 1,000-square-foot roof.

According to the Environmental Protection Agency, by keeping buildings cooler, green roofs reduce the need for air-conditioning. They improve air quality and create new habitat for birds, bees and butterflies. And they help make waterways cleaner by absorbing storm water that would otherwise flow into streets and sewers.

Sustainable South Bronx champions the economic, public health and environmental benefits of these living roofs, and has installed one on the roof of the American Bank Note Building, which houses its offices. So in an effort to show that they practiced what they preach, Carter and Chase decided to dig deep in their pockets, shelling out roughly $14,000 to design and install the green roof on their home.

Although that sum is more than three times what they would have paid for a conventional replacement roof, they expect their investment to start paying off this summer, when the roof keeps their house cooler and lowers their electric bill.

According the Rob Craudereuff, the sustainable alternatives coordinator for Sustainable South Bronx, studies showed that a typical New York City building with air conditioning saves 15 cents per square foot on energy per year with a green roof.

In addition, green roofs last twice as long as conventional roofs, so Chase expects to save in the long run.

But Carter and Chase had another, more pressing, reason to install their green roof. When it rained, their neighborhoods’ sewers would back up so quickly that they often flooded, forcing rainwater to find another place to go. Ultimately the water ran into their streets and seeped into their home.

Green roofs handle rain storms nature’s way. The plantings capture and hold half the rainwater that falls on them. Eventually, the water is slowly released back into the air through the foliage.

Although it will take about two years for the plants in the Carter/Chase roof to mature, the couple is already experiencing what proponents of green roofs say is their most important contribution, their ability to manage storm water.

“In heavy rain we no longer get flooding in our backyard and in our house,” said Chase.
Few of his neighbors knew what a green roof was capable of, but Chase and Carter’s next-door neighbor Raul Cuasent said he might consider installing a green roof on his own home if he could learn more about its benefits.

Eleanor Henson, a 28-year-old factory worker who lives with her husband across the street from the Chase/Carter brownstone, knew about the flooding problem, but said it is worse farther down the block.

Proponents of green roofs would argue that if more homes on the street had green roofs, the flooding problem would be solved. And the city may soon be encouraging more of them.

On Feb. 19, Mayor Michael Bloomberg signed legislation introduced by Queens Councilman James Gennaro to require the city to create a stormwater management plan. The plan, to go into effect next October, calls for rain barrels, cisterns, permeable pavement and green roofs in an effort to shift responsibility for rain water from sewers to individual buildings.