Energy tip #27: Landscape for energy efficiency
Energy efficiency improvements for your home don’t stop at your walls. Appropriate landscaping can not only beautify your house, it can have a large impact on your heating and cooling bills.
Determining the appropriate way to landscape your house requires knowledge not just of your regional climate, but also your microclimate. If you live on a sunny southern slope, for example, your house may be warm even in a cool climate. If you’re near a lake, your home will probably be both cooler and more humid than those farther from shore.
Microclimate matters because there’s a great deal of subtlety in proper landscaping. The two big issues to consider are sunlight and wind.
In hot climates, shade trees can significantly reduce your need for air conditioning. Not only does shade directly block sunlight from heating walls and entering windows, but plants also increase water evaporation, which leads to further cooling. The area underneath trees can be a full 25° cooler than nearby asphalt.
Tree type matters as well. Trees with high, spreading canopies are good for the south side of your house, where they can shade the roof. Lower trees are better on the west side, where they can block the setting sun. Deciduous trees are useful in areas that have cold winters, because they lose their leaves at just the time that you most want to let the sun’s heat in.
Wind breaks are another important efficiency measure. Dense, low trees and shrubs such as evergreens can significantly lower the wind chill and cut the heating costs in your home. If you live in a snowy area, plants on the windward side of your house can be used to keep drifts from forming along your walls.
Needless to say, a landscaping project is a serious undertaking. But the Department of Energy estimates that a carefully considered landscaping project can pay itself back in eight years. Check out the American Society of Landscape Architects to find a provider in your area.