"Living Roof" at Ford Motor Company Rouge Plant, Dearborn, Michigan, circa 2004

While upgrading its Rouge plant in 2002, Ford Motor Company installed a 454,000-square-foot "living roof" on the factory's final assembly building. The roof was covered with sedum, a drought-resistant flowering plant that collected and filtered stormwater runoff. It also served as an insulator, keeping the building ten degrees warmer in winter and ten degrees cooler in summer.