Energy-efficient landscapes

Abstract

A 25 foot tree reduces annual heating and cooling costs of a typical residence by about 8 to 12 percent ($10-$25). Assuming savings of $10 per household, a nationwide residential tree planting program could eventually save about $1 billion each year. Direct shade on the building will account for most of these savings in hot climates, while heating and cooling savings from reduced wind speeds and evapotranspirational cooling will be relatively more important in cooler climates. The energy conservation potential of landscapes is greatest in residential and commercial land uses, where planting space is most available and buildings consume large amounts of energy for heating and cooling. The greatest cooling savings can be obtained by shading the west side of air-conditioned buildings located in areas with the hottest climates. In cool climates the need for wind protection tends to result in a more "closed" landscape structure than in hot climates, where an "open" landscape enhances cooling breezes. The structure of energy-efficient iandscapes can complement landscapes designed for wildlife, visual quality, sustainability, and buffering. Careful design can minimize potential conflicts with fire-safe and water conserving landscapes. Tree plantings for energy conservation are likely to become more commonplace due to their relatively flexible structmal requirements, cost-effectiveness, and growing support from utilities and federal agencies.

Citation

McPherson, E.G.; Rowntree, R.A.; Wagar, J.A. 1995. Energy-efficient landscapes. In: Bradley, G.A., (ed). Urban forest landscapes: integrating multidisciplinary perspectives. Seattle: University of Washington Press: 150-160.