One page descriptions of a technique or action for a given designer, planner, engineer or project manager to take.
A Green Roof consists of vegetation and soil, or a growing medium, planted over a waterproofing membrane. Additional layers, such as a root barrier and drainage and irrigation systems may also be included.
Green roofs can be used in many applications, including industrial facilities, residences, offices, and other commercial property. In Europe, they are widely used for their stormwater management and energy savings potential, as well as their aesthetic benefits. Many US municipalities are encouraging green roofs as stormwater management and energy savings strategies. They also help reduce the heat island effect of buildings.
In arid climates, with more minimal rainfall, "brown roofs" are more commonly used. Brown roofs use crushed stone and gravel as a high-albedo roofing material that can self-seed. Brown roofs also use crushed rubble, such as brick or mortar, as a roof layer. This is intended to be allowed to self-seed and attract insects, which, while creepy, are an important part of the urban ecology and are losing habitat in urban areas.
The above photo is of the ASLA green roof in Washington DC. This roof features both extensive sedum planting at a 3 inch depth, and intensive, "wave" features, that are intended to demonstrate the performance of different plant materials.
Related External Resources:
NRCA Greenroof Systems Manual