New York Full of Possibility for Green Roofs

"Europe has had green roofs for decades, and cities like Chicago and Seattle have added many of them in recent years. But there are fewer in New York because of the cost of installing them compared with the benefits, which can be hard to quantify. The new one-year abatements, though, can cut as much as $100,000 a year from a building's taxes, and are expected to turn what has largely been a hidden luxury into a standard feature of a little-seen part of the city's landscape.

"This is just the beginning," said Kari Elwell Katzander, a partner in Mingo Design, a landscape design firm in Manhattan that works on green roofs. "It's not just about the green roof. This transcends into various ways to make buildings more green."

There are few accurate reckonings of how much of the 944 million square feet of rooftops across New York City - 11.5 percent of the total building area - has gone green, or how much more could be cultivated. But clearly there is plenty of space available. Just in Long Island City, there are 667 acres of empty, flat roofs suitable for vegetation, according to Balmori Associates, an urban design company. That is the equivalent of 80 percent of Central Park."