A Green Roof? You May Want to Consider It

No, he was told, with grants and energy savings, the payback could come within seven years. And there were other benefits: going green would extend the life of a roof membrane and increase the property's value by replacing a tar roof with a botanical wonderland. "We find it's a big selling point. Brokers bring people up and say, 'Look at the great space you have up here,'" Gulick says.

Gulick got his roof six years ago at a cost of roughly $40,000 — but are green roofs for you? What are the factors — both financial and practical — that you have to weigh when deciding whether to go green up top?

First, consider this. There are three types of roofs: extensive is the lightest weight and has the least depth of soil; intensive is the most expensive, highest maintenance, and more "park-like" in feel, with more depth of soil and variety of plants (you can even include trees); while, semi-intensive is a combination of the two (used when there are variable weight loads). The vast majority of buildings in the New York area have the structural capacity for a green roof, says Amy E. Norquist, founder of Greensulate, a company that installs green roofs (greensulate.com), who notes: "No matter the age of the roof, going green will extend the life of the waterproofing by anywhere from 40 to 75 years, but for maximum financial benefit a newer roof is preferred."

She adds: "In terms of cost, if somebody is putting on a new roof, it's probably going to be twice the cost on the front end. We do a structural analysis that determines the 'dead load' capacity of the roof. We give design/plant options based on the available capacity. If the roof has a lot of available dead load we can include more engineered soil and therefore have more plant choices. If the weight capacity is lower, we go with a simple extensive green roof that includes ground cover plants such as sedum (and even with sedum there are 600 types)."

The drought-tolerant, succulent plants placed on a green roof absorb water. In that process, the green roof is acting like an air-conditioner. "They also absorb a ton of heat and pollution," says Norquist. "They take in carbon dioxide and emit oxygen."

You can apply for grants. The New York City Department of Environmental Protection (DEP) offers a grant program. If selected, the DEP will provide funds for the design and construction of the green infrastructure system.

The New York City Green Roof Property Tax Abatement Program provides a one-year tax abatement of  $5.23 per square foot of green roof, with a maximum abatement of $200,000. "We are currently working with several co-ops for funding through the grant program totaling nearly $800,000," says Norquist.

CitiesAlive, a green organization, is holding a conference in New York City from October 5 to 8, with technical sessions directed toward design, research, and policy communities, and a focus on the latest scientific research, design, products, and policies in this area, with seminars on how to fund and implement green roofs. For more information, click here.

Photo courtesy of Greensulate