It may be more energy-wise to plant a tree than to add a few inches of insulation.
The proper orientation of trees to the house re-emphasize that most trees are beautiful, valuable and practical. Of course, the poets of yesteryear couldn't foresee our home heating and cooling problems of today.
Here are some of the ways that trees can help regulate your home's temperatures:
In the middle latitudes of the U.S., a large-leaf, deciduous (one which loses or sheds foliage at the end of the growing season) tree sited on the south-southwest side of the house may by the shading be equivalent to a half ton of air-conditioning capacity. On some house styles it could be even more. This means smaller and less expensive initial output on equipment and installation. It also means fewer operating dollars.
Pine trees (evergreen) would, of course, do well in summer but negate their contribution by blocking out solar gain in the winter. For shading purposes, trees in the far South, due to the high daily arc of the sun, are best planted on the east and west sides. In the far northern parts of the country, southerly tree location is not so significant for summer sun blockage.
Evergreen trees form wind breaks when planted on the north side of a house and are a most effective barrier for reduction of windblast and air infiltration. It is possible to reduce air infiltration from wind by 50 percent with prudent and calculated tree and shrub screening.
We all know that temperatures are lower in the shade than in direct sun. But another phenomenon is present, temperatures within the foliage may be an additional 10 percent lower than shaded temperatures. This results from the cooling effects of transpiration and evaporation of water from the stomata of the leaf. A low, branching tree over your southerly patio might be a summer boon.
In evaluating planting for your home, tree locations, and types should be considered for comfort and energy-saving features -- and also for the resale value of your home.