SIX FACTORS TO ASSESS GREEN ROOFS

摘要

Through its lifecycle, a roof has a variety of environmental impacts. However, many impacts can be controlled by building owners and facility managers, resulting in lower energy costs and longer service life. Most buildings in the U.S. are under two stories and their roofs often represent the largest portion of their building envelopes. More heat energy is lost through roofs than walls and windows. If all U.S. buildings met the 2012 level of code-mandated insulation, 700 trillion BTUs of energy would be saved. Another aspect of environmental impact involves renewable energy production. If 25% of U.S. rooftops incorporated power from solar, the energy produced would be 25 times greater than the 21 billion kilowatt hours of hydroelectric power produced by the Columbia River's Grand Coulee Dam. Keep in mind, however, that we can save more energy with insulation than we can generate from solar power. The building professional's priority should be efficiency before renewable production. Service life also affects environmental impact. A roof that lasts 30 years will consume fewer materials and resources than one that lasts 15 years. To manage your roof's green performance, take control of these six factors.