by Brianna Crandall — October 16, 2015—Building owners and facilities managers are finding value in investing in sustainable rooftop solutions to mitigate the urban heat island (UHI) effect, a phenomenon in which densely populated areas are significantly warmer than surrounding rural areas. Sustainable rooftop solutions, such as garden roofs, cool roofs and green roofs, not only lower temperatures resulting from UHI, but they also can conserve energy used by buildings, thereby reducing operating costs.
Image of Atlanta, GA, showing temperature distribution (blue = cool, red = warm, white = hot). (Atlanta daytime thermal image courtesy of NASA Scientific Visualization Studio, via Transwestern)
Commercial real estate services provider Transwestern’s Mahesh Tharoor, vice president – Energy and Sustainability, outlines the benefits of sustainable rooftops in the third-quarter edition of the company’s Building Efficiencies sustainability newsletter.
According to the article, there are several popular sustainable features being added to rooftops:
- Light-colored roofs reflect sunlight better than typical surfaces and can reduce energy consumption by the building’s cooling systems by as much as 40 percent.
- Green roofs or rooftop gardens, created by covering roofs with plants, absorb carbon dioxide and reduce heat in the area.
- Rooftop-mounted photovoltaic (PV) power stations that have electricity-generating solar panels can generate 100 kilowatts or more for commercial buildings.
UHI worsens as cities grow, making it a top priority for scientists and environmentalists, according to Tharoor. It is caused by a high concentration of buildings, concrete, asphalt and human activity. With no easy outlet, heat generated from these sources lingers in between buildings rather than escaping into the night air. The higher temperatures increase photochemical reactions that lead to an increase in smog, and pollutants that cannot scatter remain more toxic.
A study commissioned by the District of Columbia Department of General Services found that installing rooftop solutions “could be transformative for quality of life, sharply cut energy bills, improve the quality of local waterbodies, and help slow climate change cost-effectively.”
Proactive building owners can capitalize on the cost-effective opportunity to conserve energy, reduce carbon emissions, and stem the tide of climate change. Interested investors can learn more from ENERGY STAR, the Cool Roof Rating Council, organizations like the Global Cool Cities Alliance, and the Environmental Protection Agency’s searchable database of UHI initiatives. Transwestern’s dedicated sustainability experts also can provide valuable insight and consulting services.
Tharoor’s article, “Take It from the Top: Owners Turn to Rooftops to Mitigate Urban Heat Island, Lower Costs,” is available for free download from the Transwestern Web site.
