There are many options for building a green roof. For a more comprehensive approach to designing green roofs, see LEEDuser’s green roofs strategy page.
Why are sloped roofs treated differently? A surface absorbs more energy from the sun when it is parallel to the ground plane. In the summer months when the heat island effect is more of a problem, the sun is nearly overhead, and flat roofs are in a position to absorb more heat, so it’s more important for them to have a higher