Ecological Roofing Materials

Eco-friendly roofing can lower surface temperatures (see Reference 5).

Eco-friendly roofing can lower surface temperatures (see Reference 5).

Whether you are building your new residence or live in an existing house, modifications in your home's roof design can offer economic and environmental advantages. For example, a study released by Canada's National Research Council found that green or vegetated roofs can reduce summer energy demand by more than 75 percent. That is only one of several ecological options for upgrading your existing roof to one that is more energy and resource efficient. (see Reference 1, page 2.)

Green or Vegetated Roofs

A green roof is essentially a rooftop garden. A layer of vegetation covers the roof instead of traditional materials like shingles. Green roofs offer several benefits: They can reduce your energy costs while providing aesthetic value. Because you are using less energy, your carbon footprint is reduced, as are greenhouse gas emissions. The vegetation also slows water flow and runoff. This in turn allows you to better manage storm water around your house, preventing pooling and other negative effects. (See References 2 and 3.)

Recycled Materials

Utilizing recycled products on your roof reduces landfill waste and the energy needed to produce new items from virgin materials. The U.S. Environmental Protection Agency provides guidelines for the recommended percentage of postconsumer content and recovered materials in roofing options. For example, the EPA suggests an aluminum roof contain between 20 and 95 percent postconsumer content and recovered materials. (See Reference 4.)

Energy Star Products

Energy Star-qualified roof products save energy and reduce ambient temperatures through the use of reflective materials. By reflecting heat from the roof, less heat is transferred to the attic space below, which helps reduce summer cooling costs. Energy Star estimates that installation of these products can save up to 15 percent of cooling costs. Savings vary with the roof design, insulation and climate in which you live. The EPA documented a case study at Our Savior’s Elementary School in Florida where installation of an Energy Star-labeled roof saved the school $850 in annual energy costs and reduced annual carbon dioxide emissions by 22,300 pounds. (See References 5 and 6.)

Urban Heat Islands

An added benefit of ecological roofing materials concerns their effects on urban heat islands. Buildings with traditional dark-colored roofs absorb heat and can raise the air temperature, especially during summer months. This effect is more pronounced in densely populated urban areas. Simply installing a white-colored roof can have a profound impact. A study by the National Aeronautics and Space Administration conducted in New York City during the summer of 2011 found that white-colored roofs measured up to 42 degrees Fahrenheit cooler than dark-colored roofing materials. The potential exists for urban areas that promote widespread use of white roofs to reduce greenhouse gas emissions and energy costs significantly. (See Reference 7.)

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