Largest living roof

The roof of the Ford Motor Company's Rouge factory in Dearborn, Michigan, USA, has had 42,180 m²(454,000 ft²) of low-growing vegetation called sedum planted on it, making it the world's largest 'living roof'. Planted in a 7.6 cm (3 in) thick mat-like material, the vegetation insulates the roof, saving on heating costs, and it also lasts longer than conventional roofing because it doesn't expand or contract as outside temperatures change. In addition, it creates a habitat for birds and butterflies. Rouge was famous as the primary production facility for the Model A Ford, successor to the Model T.