Green roofs start to sprout on urban homes
Low-maintenance sedum cuts energy costs as well as greenhouse gases. Roofs are costly, though.
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The cost is high: between $15 and $35 per square foot. Carter and Chase's 1,100 square-foot brownstone roof cost $14,000 to design and install, more than three times the $6,000 it costs to replace a conventional roof of that size. It helps that the green roof will last an estimated 30 or 40 years, rather than the decade or so one might expect from a regular roof, Weber says. [Editor's note: The original version misquoted the price of the roof repair.]
The cost can be less if neighbors get together and use the same company to design and install several roofs at the same time. Muroff says the most cost-effective aggregate square footage for pursuing a green roof is 5,000 square feet or more.
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Boston's hip Jamaica Plain neighborhood is contemplating moving in this direction as well. Forty or so residents gathered last month to hear how green roofs could work for their homes and community.
"Last year, if there was a meeting like this, two, maybe three people would have shown up," says guest speaker Weber. "Now this is a hot topic, and it's about cooling our cities and our neighborhoods down."
She says such roofs can work for almost any home, from the suburban pitched roof to the flat roofs on Jamaica Plain's "triple deckers" (three-family homes).
Although homeowners may want to make elaborate plans for an urban forest atop their home, most houses cannot support the intensive green roofs found on big commercial buildings, with trees and lush foliage. Residential installations mostly feature a maximum of four inches of soil.
The green sedum on the Bronx brownstone is the most common plant for residential green roofs, experts say. It is a succulent, flowering plant that requires little water and minimal soil (meaning less weight).
Although green-roof maintenance is necessary at first (the sedum requires occasional weeding or watering), once the roof is well established after about two years it only needs to be checked every six months or so, says Rob Crauderueff, the sustainable alternatives coordinator for Sustainable South Bronx (SSB), the nonprofit group Carter established in 2001 to help green the Bronx while developing a local, "green collar" workforce.
In the case of his home, Chase says he looks at the high cost as both a "romantic" and practical investment.
The romantic motivation comes from the feel-good moments he has watching sunsets – and the next Fourth of July fireworks – from their rooftop, all the while knowing they're giving a little bit of metropolis back to Mother Nature.
"Out here in the Bronx," Chase says, "we're starved for land to play with. There's no room for gardens in front of our homes.... Compared to some home improvements, this is a guiltless pleasure."
Carter and Chase also feel like they're giving back to the community by supporting the fledgling green-roof industry and having SSB employees perform the installation and maintenance.
Mr. Crauderueff recommends hiring a contractor who can design, install, and maintain a green roof so they have an added incentive to do a good job from the beginning.
Neighbors and a video crew from a new show on the Sundance Channel hosted by Carter gathered Oct. 5 to watch the installation of the green roof, which only took a day. The SSB crew used a "laddervator" (a ladder with escalator-like sides) to help carry the materials up to the roof.
The reactions to the new roof by her neighbors were varied.
"Some of them were probably like, 'Those crazy environmentalists are at it again,' " Carter says. "But I think there's a lot of buzz around here about green roofs, especially for storm-water management. They're asking 'Could that work for me, too?' "