I admit that my experience is limited. We designed just one green roof as a demonstration project for a storm water authority, circa 2004. The utility especially likes the decrease in rate of run off. In fact we have two spouts side by side to demonstrate the difference between the vegetated roof and an equal area of typical roof. The difference is dramatic.
Lately I've been wondering, "Is it just me or has the din about green roofs died down?" The touted benefits list is fairly long.
- The roofing lasts longer
- Provides extra insulation
- Moderates the temperature differential between inside and outside
- Slows time of concentration of storm water runoff
- Absorbs CO2
- Eliminates the heat island effect of the building
- Provides habitat