Financial Benefits Of Green Roofs
OTHER PARTS OF THIS ARTICLEPt. 1: Green Roofs LEED to Multiple BenefitsPt. 2: This PagePt. 3: Extensive or Intensive? Green Roofs ExplainedPt. 4: Green Roof Tips: Roof Structure and MaintenancePt. 5: Green Roof Professional Certification Program Announced
There are several other practical, business-scenario benefits to green roofs, as well. For one, as with many other green strategies, new rebates and tax deductions are cropping up that can help ease the financial burden. New York City, for instance, recently passed a law that provides a one-year tax abatement of $4.50 per square foot for buildings that install a green roof on at least half of their rooftop space. Green roofs can help reduce stormwater run-off, mitigate the urban heat island effect and clean the air, benefits that accrue to the community. A study completed by three researchers at the University of Michigan found that greening 10 percent of Chicago roofs would result in public health benefits of between $29.2 and $111 million, due to cleaner air. For Detroit, having 10 percent green roofs would result in a public health benefit of between $24.2 and $91.9 million.
There could be individual facility cost saving benefits as well. A recent study by The Lady Bird Johnson Wildflower Center at the University of Texas showed that a green roof could reduce a building’s air conditioning bill by about 21 percent compared with a traditional, tar-based black roof. Single-story buildings with a high roof-to-wall ratio will experience the biggest energy saving benefit from a cool roof.
Finally, many experts suggest that green roofs help lengthen the life of the roof membrane underneath the green roof and the facility’s waterproofing. Because of the layers of planting medium and the plants themselves, the membrane is protected from temperature differentials, and the resulting expansion and contraction that normally shorten a roof’s life. “You may be able to eliminate one or two cycles of roof replacement,” says Steven Peck, president of Green Roofs for Healthy Cities.