http://www.sustainablebusiness.com/i...splay/id/23052
FedEx Opens Enormous Green Roof at Chicago O'Hare Airport
The FedEx Express cargo facility at Chicago's O'Hare International Airport is now topped by a huge green roof - 175,000 square feet - the size of three football fields.
The roof is plainly visible from planes as they land at one of the world's busiest airports. The only airport that has a bigger one is in Frankfort, Germany.
Although it's the largest by far, there are 12 other green roofs at O'Hare and Midway airports. Airports mostly consist of large areas of impermeable concrete surfaces - green roofs cool the urban heat island effect and help with stormwater management. They also reduce airport noise, reduce air pollution, and lower energy costs by 35% a year.
"Green roofs act like a sponge for heat, light and water and they conserve energy by maintaining a constant temperature inside the building. They also help to collect storm water," explains FedEx Deputy Commissioner of Sustainability Amy Malick.
FedEx calculates it will save $0.20 cents per square foot of green roof per year on energy costs alone and it will absorb about two million gallons of storm water each year, which would otherwise run off into the sewer system.
Like many green roofs, this one is covered with sedum - a low-growing, drought- tolerant plant....