[Scpg] Green Rooftop Technology

scpg-admin at arashi.com scpg-admin at arashi.com
Mon May 28 09:14:00 PDT 2001


Hi everyone
	Margie Bushman found this article and more links to Green Rooftops, check 
it out
						wes

 >http://www.cnn.com/2001/NATURE/01/01/rooftop.gardens.enn/index.html







                   January 1, 2001
                   Web posted at: 12:01 p.m. EST (1701
                   GMT)

                   By Environmental News Network staff

                   During the summer months, the
                   temperature of a conventional flat
                   rooftop can soar up to 140 degrees
                   Fahrenheit - hot enough to fry an egg.

                   This heat creates tremendous updrafts, circulating tiny 
particles that can clog
                   lungs. The additional heat increases the need for 
electricity production, which
                   further adds to air pollution.

                   By contrast, a grass rooftop can't get any hotter than 
about 77 degrees. This
                   innovative technology can help relieve city smog and cut 
energy consumption.
                   With enough green roofs, the temperature of a entire 
city can decrease.

                   A 3- to 7-degree temperature drop translates to a 10 
percent reduction in air
                   conditioning requirements. For a one-story structure 
with a green rooftop,
                   cooling costs can be cut by 20 percent to 30 percent.

                   A recent study done by Weston Design Consultants for the 
city of Chicago
                   estimates that the greening of all of the city's 
rooftops would produce
                   $100,000,000 in saved energy annually. Peak demand would 
be cut by 720
                   megawatts - the equivalent energy consumption of several 
coal-fired generating
                   stations or one small nuclear power plant.

                   Green rooftops offer other environmental benefits. They 
capture and filter air
                   pollutants and retain as much as 50 percent to 70 
percent of the storm water that
                   they capture. This reduces storm water contamination and 
the risk of flooding.

                   Green rooftop technology replaces traditional flat 
rooftops with a series of
                   carefully engineered layers. A water- and root-repellent 
membrane is installed on
                   top of a reinforced roof structure. A drainage layer 
separates growing material
                   from the underlying membrane.

                   A filter cloth keeps the drainage layer from getting 
plugged by the growing
                   medium, which constitutes the top layer. This growing 
medium is designed to be
                   as light as possible and still support plant growth.

                   Significant long-term savings can offset the cost of 
installing a green rooftop.
                   Green rooftops last twice as long as standard roofs, 
reducing maintenance and
                   replacement costs. They also muffle sound, creating a 
more efficient work
                   environment.

                   Green rooftop technology is just being introduced in the 
United States and
                   Canada, but it is a common feature of construction in 
Germany, France, Austria,
                   Norway, Switzerland and other European countries.

                   In North America, cities such as Chicago and Toronto 
have established green
                   rooftop demonstration projects on city-owned buildings. 
Washington, D.C., and
                   Portland have begun to conduct research on the benefits 
of public green
                   rooftops.

                         Copyright 2000, Environmental News Network, All 
Rights Reserved




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                   RELATED SITES:

                        City of Chicago
                        Heat Island Group
                        Green Roofs for Healthy Cities
                        Greenroofs.com
                        Urban Agrigulture Notes
                        Rooftop Gardens Resource Group

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