Cool Roofs

The document outlines four types of cool roofs—naturally cool, coated, insulated, and green (vegetated)—and details their capacity to reduce building energy use, mitigate the urban heat island effect, and lower greenhouse gas emissions. It highlights specific benefits such as a potential 15 percent reduction in air conditioning energy for single-story buildings and the ability of green roofs to manage storm-water runoff, illustrated by examples in Washington, D.C.

• Cool roofs can significantly reduce building energy consumption and costs. A cool roof may lower the energy required for air conditioning by up to 15 percent in single-story buildings. Furthermore, upgrading U.S. commercial roofs with high R-value insulation is estimated to result in annual energy savings exceeding $2 billion.
• Cool roof technologies contribute to climate change mitigation and the reduction of the urban heat island effect. A 1,000 square foot white roof can offset 10 tons of carbon dioxide over 20 years. On a global scale, whitening all eligible urban flat roofs could prevent 24 Gigatonnes of CO2 emissions, which is equivalent to removing 300 million cars from the road for two decades.
• Cool roofs provide secondary benefits, including increased solar energy production and reduced maintenance. Lowering surface temperatures can increase the energy production of photovoltaic (PV) solar installations by up to 16 percent. Additionally, reflecting sunlight reduces the damage caused by ultraviolet and infrared radiation, lowering replacement and maintenance costs.
• Green roofs offer specific environmental services beyond heat reflection, such as air purification and storm-water management. A 3-inch green roof can hold between 0.75 and 2 inches of rain. In Washington, D.C., greening 80 percent of rooftop space would result in a 56 percent reduction in rooftop runoff, mitigating sewer overflows and protecting watersheds like the Chesapeake Bay.

APA

Brock, S. (2012). Cool Roofs. Environmental and Energy Study Institute. https://www.eesi.org/files/cool_roofs_072412.pdf

Chicago

Brock, Samuel. Cool Roofs. Environmental and Energy Study Institute, 2012. https://www.eesi.org/files/cool_roofs_072412.pdf.

Wikipedia

{{cite report |last1=Brock |first1=Samuel |title=Cool Roofs |publisher=Environmental and Energy Study Institute |date=July 2012 |url=https://www.eesi.org/files/cool_roofs_072412.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{brock2012cool, author = {Brock, Samuel}, title = {{Cool Roofs}}, institution = {Environmental and Energy Study Institute}, year = {2012}, month = jul, url = {https://www.eesi.org/files/cool_roofs_072412.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }