Greenroof's A Growing Business

The Durst Organization says it will spend between $750,000 and $1 million to install more than an acre of green space atop its Midtown Manhattan buildings. The company's commercial portfolio includes One Bryant Park, One World Trade Center and Four Times Square, among others.

Amy Norquist, president and chief executive of Greensulate, a Manhattan-based company that designs, builds and maintains green roofs, and whose company helped the Fashion Institute of Technology install nearly 20,000 square feet of green roof two years ago, said the benefits of such projects include improved air quality, energy efficiency, decreased temperatures, storm-water management, mitigation of climate change and improved productivity.

In recent years, the New York state Assembly introduced a tax abatement of $4.50 a square foot for the installation of green roofs in New York City, and the Department of Environmental Protection introduced funding for green roofs with a focus being storm-water management.

The Durst Organization's green-roof system is able to retain about 55,000 gallons of water that would otherwise wind up in the sewer system. The company's first green roofs, which are covered in a mixture of hardy, low-lying plants that don't require deep soil, were installed last March above the Durst offices at One Bryant Park and at 675 Third Ave.

By spring, the company will have installed green roofs on eight of its buildings, including 205 E. 42nd St., 655 and 733 Third Ave., 1133 and 1155 Sixth Ave. and 114 W. 47th St.

In 2007, Tishman Speyer installed an 18,000-square-foot green roof atop Radio City Music Hall, saving approximately 566,000 gallons of water from the city's storm-water system annually. The Albanese Organization also plans to install a 6,050-square-foot green roof on a commercial building the company will construct at 510 W. 22nd St.