Green Roof Definition Epa

A green roof is a vegetative layer grown on a rooftop.

Green roof definition epa.

It may also include additional layers such as a root barrier and drainage and irrigation systems. The green roof at the epa regional office is an extensive modular design meaning that the plants are growing in 2 x 4 trays made of recycled plastic. Due to the volume reduction actual nutrient loadings from green roofs are less than asphalt roofing runoff or otherwise manageable at the downspout. Green roofs have a layer of plant material that absorbs water like a sponge.

They are particularly cost effective in dense urban areas where land values are high and on large industrial or office buildings where stormwater management costs are likely to be high. A green roof or rooftop garden is a vegetative layer grown on a rooftop. As with trees and vegetation elsewhere vegetation on a green roof shades surfaces and removes heat from the air through evapotranspiration. Green roofs provide shade remove heat from the air and reduce temperatures of the roof surface and surrounding air.

They capture water when it rains slowly releasing it through evaporation and plant use. A green roof or living roof is a roof of a building usually commercial that is partially or completely covered with vegetation and a growing medium planted over a waterproofing membrane. Using green roofs in cities or other built environments with limited vegetation can moderate the heat island effect particularly during the day. These trays cover 20 000 square feet or almost 60 of the 35 000 square foot total roof surface above the 8th 9th and 10thfloors of region 8 epa headquarters.

A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium planted over a waterproofing membrane. Green roofs can significantly reduce the amount of rain water that would otherwise run off an impervious roof surface. It may also include additional layers such as a root barrier and drainage and irrigation systems. These two mechanisms reduce temperatures of the roof surface and the surrounding air.