Npr s chris arnold reports.
Green roofs npr.
Commercial green roofs are not roof gardens.
Grhc develops and protects the market by increasing the awareness of the economic social and environmental benefits of green roofs green walls and other forms of living architecture through education advocacy professional development and celebrations of excellence.
Green roofs for healthy cities grhc is the north american industry association for the green roof and wall sectors.
Many of them can t take foot traffic.
Large enough green roofs such as commercial vegetative roofs may even reduce the risk of local flooding during heavy rain.
We took a field trip to the largest green roof in new york city.
The increased urbanization of towns and cities has resulted in less green space and more impervious surfaces.
In the most basic sense green roofs are a layered combination of vegetation and membrane over a building that can help insulate and provide water management.
With green roofs that water instead of going into the drain and polluting the environment ends up just evaporating the atmosphere through the leaves of these plants.
A green roof also helps control storm water runoff and retention.
Although there are no precise definitions of them an extensive green roof has a shallow growing medium usually less than six inches with a modest roof load limited plant diversity minimal watering requirements and is often not accessible.
But now some of those roofs are going green.
Instead they re like green skins layers of vegetative matter that grow directly on.
They fall into three main categories extensive intensive and semi intensive.
And then there s what scientists call the heat island effect which basically means that cities are significantly warmer than the surrounding areas.
Can you collect water runoff from a green roof.
Npr s ketzel levine reports.
This absorption of stormwater also improves local water quality.
Precipitation generally runs off the roof of a building into gutters and flows into a storm sewer.
Green roofs have become natural fits for many public buildings as well thanks to large scale environmental and financial benefits such as energy efficiency storm water management sound insulation and the development of habitats for birds and other urban creatures.
Modern systems help mitigate the heat island effect create habitats filter pollutants sequester carbon and even increase agricultural and amenity space.
Then we imagined what the city could be like if all of its roof space was green.
