The American Society of Landscape Architects has been conducting a long term study into the benefits of installing a green roof.
Some of their ongoing results make for very interesting reading:
- the green roof created a 10 percent reduction in building energy use during winter months and negligible difference in the summer
- from July 2006 to May 2007 the green roof retained nearly 75 percent of the total rainfall
- the roof typically retained 100 percent of a one-inch rainfall.
- the green roof has been substantially cooler than conventional black roofs on neighboring buildings.
Someone really needs to try and come up with a good reason why we aren't doing more of this in Australia. There is no excuse for building a new building with a flat concrete roof and not doing this.