Rooftops of businesses across the country are blooming with vegetation, and research shows that these roofs have more to offer than just aesthetic appeal.
By replacing the impermeable surface of a standard roof with vegetation, a green roof provides numerous environmental and economic benefits.
“A lot more companies are becoming conscious of building practices. I think as those begin to take hold, a lot more people will look at green roofs as something that will be beneficial in the long run,” says Leigh Whittinghill, a graduate student on the green roof research team at Michigan State University.
The university’s green roof research team advised Ford Motor Co. on the installation of a 10.4 acre green roof on top of its plant in Dearborn, Mich. The green roof is saving the auto company in heating, cooling and roof replacement costs.
The factory’s green roof is also providing a habitat for birds, butterflies and insects and is reducing the amount of contaminated stormwater that flows into nearby Rogue River.
A study conducted by the Center for Climate Systems Research at Columbia University shows that green roofs can help to mitigate the “urban heat-island effect” created when concrete buildings and asphalt surfaces absorb solar energy and turn it into heat.
The study looked at several green roofs in New York City, including the 10,000-square foot green roof on the Con Edison power plant’s Learning Center in Long Island City.
To further its mission of stewardship of the land, the American Society of Landscape Architects in Washington, DC installed a green roof on its headquarters.
Data collected from ASLA’s green roof demonstration project show that temperatures on the ASLA roof have been as much as 32 degrees less than conventional black roofs on neighboring buildings, and that the roof retained 76.7 percent of the 11.83 inches of rain that fell during the first data collection period.
The higher initial cost of installing a green roof as compared to a standard roof may be a barrier to some businesses.
However, the lasting economic benefits of green roofs can make up for the installation cost, explains Steven Peck, president of Green Roofs for Healthy Cities. Also, with the movement toward integrating green infrastructure, cities across the United States, from Portland to Cleveland to Philadelphia, are providing a variety of financial and regulatory incentives to make it easier for businesses to install green roofs.
Peck suggests contacting your local representative to find out what program incentives your city may have for installing a green roof.