San Francisco became the first U.S. city to mandate #solar and #living roofs on most new construction starting January 2017. This legislation dictates that 15-30% of roof space will incorporate solar, living roofs, or a combination of the two. Dense areas suffer from "urban heat island effect" where dry, un-shaded rooftops and pavement are baked by the sun and then heat the air around them. Ambient air temperatures in these environments average at least 5 degrees hotter than surrounding rural areas.
In 2017 Denver voters passed the "Green Roof Initiative" to likewise address the urban heat island effect. The city is finalizing its revised "Green Buildings Ordinance" next month, at which point new building codes, which aim to moderate roof temperatures and mitigate urban heat islands, will be enforced. Structures of at least 25K-ft2 with new construction or re-roofing projects will be required to install cool roofs and use available roof space for gardens and/or solar panels. A prime example of the efficacy of the legislation, Denver's EPA building, has a cool roof that measures 80 degrees in the summer vs. 170 degrees on the dark roof across the street.
Green roofs and cool roofs last at least three times as long as traditional roofs. When combined, solar panels give shade to vegetation while plants keep the roof cooler. Benefits include reduced energy consumption, improved air quality, lessened noise, better storm water management, and increased #biodiversity. All city dwellers should want their cities beautified with cool green roofs that generate power – and create a better quality of life.
To learn more about cool roofs or options to finance them, contact us!
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