Chicago mayor Richard Daley became a strong advocate for green roofs of live plants while traveling in Europe. Now 120 will be built including one on City Hall and one above a huge subterranean parking garage and commuter train terminal in Millennium Park. As explained in BioCycle articles, green roofs reduce sewer overflows by absorbing rain (especially when compost is used) filter out pollutants, oxygenate the air, and keep buildings cooler in summer while cutting electricity use.
In New York City, landscapers last month were installing a green roof (covering 35,000 sq ft) at the Silvercup Studios where parts of the HBO series, “The Sopranos,” are filmed. Proponents hope that the project data will convin commercial property owners and developers to use the concept widely. “We are looking to demonstrate to the government, the public and private business that green technologies are an economic benefit,”said the co-owner of Silvercup Studios. The project obtained a major grant from Clean Air Communities which is devoted to reducing air pollution and energy consumption in low-income neighborhoods. With current technology, green roofs typically cost $8 to $10 a square foot, while a regular roof costs about $4 to $8. New York City has approximately 60,000 sq ft of green roofs built or under construction. Other green roof examples in North America include: a 1.5 acre installation at the Gap corporate office in San Bruno, California; an 8-acre multilevel roof on Salt Lake City’s Latter Day Saints Conference Center; a 10.4 acre roof on the Ford Motor Company’s truck plant in Dearborn, Michigan; and a green roof planned for the remodeled California Academy of Sciences in San Francisco’s Golden Gate Park.