Shade trees are beautiful additions to a home landscape and also function as natural air conditioners, shielding the home and yard from the hot summer sun. In the winter, deciduous trees conveniently shed their leaves, enabling the rays of the sun to warm the house. Trees are good for the environment, absorbing carbon dioxide, but care must be taken in choosing and positioning them.
According to Geoffrey Donovan, Ph.D., author of a 2009 study on the impacts on energy of shade trees, trees planted no further than 60 feet from the south and west sides of a house can lower air conditioning bills by about 5 percent between May and September (see References1). Placing the trees so they cast their shade on windows will enhance the cooling effect. However, if trees are planted too close to the house, overhanging branches can damage shingles, dump a lot of debris in the gutters and create an easy path for squirrels to gain access to the house.
According to the University of Georgia Cooperative Extension, large shade trees should be planted no closer to a building than half the width of their spread at maturity. They should be spaced no closer than the full width of the mature spread from the trunk of another tree (see Reference 2).
A combination of evergreen and deciduous trees planted on the north and east sides of the home can help break the force of winter winds and even function as natural snow fences to keep snow from drifting on driveways.
When selecting and planting shade trees, other factors should be considered as well as distance from the house. Trees with wide upright or vase-shaped growth are the best shapes for shading the home. Select tree species that will drop their leaves in the winter, allowing sun to warm the home. Choose trees that thrive in the climate and soil conditions in your yard.
Shade trees can also provide cooling and enhance beauty and privacy for outdoor living spaces. Consider the visual effects of the tree during its growth and maturity. Ideally, the size and shape of the tree should balance and not overpower the size and design of the home and should not block the view of the house from the street or the view of the yard from the house (see Reference 3).
The roots of mature trees grow very wide and deep and can interfere with septic tanks and sewer lines, so it is best to avoid planting near these structures. Likewise, keeping trees away from electric lines will avoid problems as the trees grow and mature. Position trees to avoid blocking drivers' views from the driveway or the street.