GREEN ROOFSAmerican cities have a surprising amount of wasted open space. Even in densely packed urban areas like New York City, the prime real estate atop roofs is given much less consideration than one would expect from a populace that values each square foot of space so highly. This oversight is a real shame, because there is so much that can be done to improve the local environment and quality of life, simply by fixing up a roof.
The average city rooftop is layered with black tar, a material which traps sunlight and heat, raising the temperature of the surrounding area. The heat trapped by dark, flat roofs elevates city temperatures as much as ten degrees Fahrenheit - contributing to what scientists call the “urban heat island” effect.
Cool RoofsThe easiest and quickest solution to combat the urban heat effect is simply to turn hot dark roofs into“cool roofs” by painting them with a basic coating of light-colored water sealant. In the same way that white clothing helps keep you cool in the summertime, white roofs reflect sunlight and heat. If all the roofs in New York City were ?cool roofs?, the city would save some $100 million dollars per year in cooling costs.
Green RoofsAn even better alternative to cool roofs (albeit one that requires more time and effort) is to turn waste roofs into landscaped
Green Roofs. Green roofs having the same cooling effect of white roofs, with the added benefits of:
* Providing amenity space for building users ? replacing a yard or patio
* Increasing roof life span* Reducing storm water run off* Providing noise insulation
* Filtering pollutants and CO2 out of the air
* Providing locally grown food (with roof-top vegetable gardens)
* Increasing wildlife habitat in built up areas
* Reducing heating (by adding mass and thermal resistance value) and cooling (by evaporative cooling) loads on a building* Reducing the urban heat island effect
