What is the difference between a green, and a blue-green roof? This short videoclip explains in all, in Dutch..
STOWA, the foundation for Applied Water Research, created an animation explaining the basic differences between conventional greenroofs, and the newer blue-green roofs. Where in conventional green roofs the water storage capacity is very limited, in blue green roofs more water can be stored and managed (added/used/drained) in the higher drainage layer such as the WRB85i by Optigreen.
But let the video do the explaining!
Click to watch