Professional Practice

Using Low-Impact Materials: Reflective Materials

Over 7,500 square feet of asphalt was replaced by landscape areas and high albedo paving, reducing the urban heat island effect. Taylor 28, Seattle, Washington / Mithun.

Solar Reflectance has a significant impact on surface air temperatures in the built environment. Materials with low solar reflectance absorb a larger amount of solar energy, which leads to higher air temperatures and increased energy use. In cities, this contributes to the urban heat island effect. Using reflective, "cool," or white materials helps reduce air temperatures and energy costs by minimizing the use of air conditioning to cool buildings.

Reflective materials offer high solar reflectance ¨C they have an innate ability to reflect sunlight and reduce solar heat absorption. These materials can stay cool in the sun and also have high thermal emittance ¨C they radiate instead of absorb heat. Roofs with high thermal emittance and solar reflectance can stay up to 50-60¡ãF cooler than roofs with conventional materials.

Reflective materials also last longer than conventional materials, which absorb heat and break down faster.

Roofs and pavement can account for 60 percent of ground surfaces in many urban areas. The Environmental Protection Agency (EPA) has actively promoted the use of reflective roofs and roadways as a cheap and effective way to reduce greenhouse gas (GHG) emissions. Chicago has issued a reflective roof ordinance, and California has announced reflective roof rules for government-financed buildings. Reflective pavements should also be considered.

Sources: s, Environmental Protection Agency; ¡°," Hashem Akbari, Surabi, Arthur Rosenfeld, Springer Science + Business Media B.V., 2008

Organizations













Resources

, Global Cool Cities Alliance

, The Dirt, American Society of Landscape Architects

, U.S. Environmental Protection Agency

, EPDM Roofing Association

Interview with Sadhu Johnston, Chief Environment Officer, City of Chicago, American Society of Landscape Architects  

, The Dirt, American Society of Landscape Architects

, Smart Cities Dive

s, Lawrence Berkeley National Laboratory

, Landscape Architecture Network

, Landscape Architecture Magazine

, University of Tennessee Center for Clean Products, 2009

Research

¡°," Hashem Akbari, Surabi, Arthur Rosenfeld, Springer Science + Business Media B.V., 2008

¡°,¡± Pomerantz, M., Akbari, H., Chang, S., Levinson, R., Pon, B., Lawrence Berkeley National Laboratory

Government Resources

, City of New York

, California Energy Commission

s, Energy Star

, Department of Energy

Projects

, Seattle, Washington
Mithun

, Dallas, Texas
TBG Partners