On average, a well-designed landscape provides enough energy savings to return an initial investment in less than 8 years. An 8 foot deciduous (leaf shedding) tree, as an example, costs about as much as an awning for one large window and can ultimately save your household hundreds of dollars in reduced cooling costs, but still admit some sunshine in the winter to reduce heating and lighting costs.
Using shade effectively requires that you know the size, shape, and location of the moving shadow that your soon to be planted “Energy Saving Tree” will cast. Trees can be selected with appropriate sizes, densities, and shapes for almost any shading application. Trees with high, spreading crowns (i.e. leaves and branches) can be planted to the south of your home to provide maximum summertime roof shading. Trees with lower crowns to the ground are more useful on the west side of homes, where shade is needed from lower afternoon sun angles.
A 6 to 8 foot deciduous tree planted near your home will begin shading windows the first year. Depending on the species and the shape of the home, the tree will shade the roof in 5 to 10 years. If you shade an air conditioner, the unit can increase its efficiency by as much as 10%.
It may be useful to sketch your plan first taking several things into consideration. Sketch a simple scaled drawing of your yard, including your home, walks, driveways, patios, or sidewalks. Locate your buried utilities, (i.e. electric, phone, cable, gas, water, and sewer lines) by calling the One Call Diggers Hotline at 1-800-331-5666. Draw arrows to show sun angles, circling the areas of your yard needing shading. Highlight areas where landscaping height or width may be restricted, such as under utility lines or along sidewalks. You may wish to have your electric, phone, or cable service installed underground to accommodate your landscaping.
Perhaps your home is located in such a way that the best place for trees is in your neighbors yard. Bringing your neighbors into your plans could benefit everyone involved.
Trees have a life span of many years and can become more attractive and functional with age. But poor planning of improvements often creates trouble. Ensure proper placement and minimal maintenance before you plant.
Should you plant a slow-growing or fast-growing tree? Although a slow growing tree may require many years of growth before it shades your roof, it will generally live longer than a fast growing tree. Also, slow growing trees often have deeper roots and stronger branches that are less prone to breakage by windstorm or heavy snow loads.
Share your drawings and ideas with your local nursery or landscape specialist. As long as you have defined spaces in which plantings are possible, your specialist will be able to help you make good decisions. Now go back to your drawings and add the new information on species, shape, and mature size spacing. This provides a final, pre-purchase review to make sure that all elements will work well together toward your ultimate goal of energy savings.