Hundertwasser, the Austrian philosopher, artist and architect has been an inspiration for people interested in green roofs in world. Hundertwasser believed, like Le Corbusierm, that what one took from the land  should be replace at roof level when buildings are built.

Green Roofs of the World 1 - Moos Filtration Plant Zurich

Built in 1913, the Moos Filtration Plant near Zurich cleans the water for the people of Zurich. When first opened the roofs consisted of exposed waterproofing. However during the first summer, a summer of very high temperatures, the water below the roof deck became polluted with bacteria. To resolve this problem there was a need to cool the water below during the summer time. A simple but effective solution was found locally  Local meadow soil.

On top of the membrane, a gravel layer was laid to provide drainage and then 300 mm of local meadow soil was placed above. Of course the local meadow soil was awash with flower and grass seed. This soon developed into a flourishing meadow. And became some of the largest green roofs or living roofs in Switzerland.