Landscaping should be included in your long-term plan for reducing heating and cooling costs. If your home is currently subject to glaring summer sun or brutal winter winds, you could improve your home efficiency from a well-crafted landscaping design.
Your landscaping can also improve privacy, reduce street noice, and control dust. Add these benefits to the beauty of a mature landscaping, and it's no surprize that the presence of trees and shrubs can raise a home's resale value by 10 to 20 percent.
There are many benefits to landscaping as documented by the U.S. Department of Agriculture and the Department of Energy. Studies show that carefully positioned trees can reduce an average household's energy consumption by 20 to 25 percent.
Landscaping also has important positive environmental effects. Plants consume carbon dioxide and water through photosynthesis. This carbon is stored, or sequestered, in the plant itself and its surrounding soils. If you want to offset your carbon foot print, this is one great way to do it.
The shade cast by landscaping will typically reduce your home's summer air-conditioning costs by 15 to 50 percent. The savings may be up to 75 percent for small mobile homes. The savings are the greatest in hot climates and for homes with little existing shade.
You may have noticed that parks and forests are always cooler than nearby city streets. This is because trees block sunlight before it can reach the ground, and their canopies of leaves release cooling water vapor through a process called evapo-transpiration.
Several studies show that summer daytime are temperatures in neighborhoods with mature trees are three to six degrees cooler than in newly developed areas with no trees, and that large urban parks are up to seven degrees cooler than surrounding neighborhoods.
Planting trees may be ten times more cost-effective than building new electrical generating plants to meet summer cooling demands. A 1992 study by the Lawrence Berkeley Lab estimated that building new power plants to meet electrical peak loads cost an average of 10 cents per kilowatt-hour. The study showed that decreasing peak-load consumption by planting trees cost only 1 cent per kilowatt-hour.
The effectiveness of landscaping in reducing the cost of cooling your home will depend on several factors:
If your home is located in a hot part of the world, and has large south-facing windows and a dark-colored roof, you'll have the greatest need for summer shading.If you live in the north or on the coast and you rarely need air-conditioning, the shade cast by your plantings will be less significant.
Landscaping can also reduce your energy costs in cold weather. Landscaping that creates a wind-break can reduce your winter heating bills by up to one-third.
Moving air carries heat much more quickly than still air. Wind blowing on your home will cool its exterior surfaces, causing heat inside the home to conduct through the walls and other surfaces more quickly. Wind will also work its way through cracks and other openings in the home's shell, causing drafts and driving up heating costs.
Owners of rural homes have long recognized this principle when designing shelter breaks around their buildings. One study conducted in South Dakota found wind-breaks to the north, west, and east of houses cut fuel consumption by an average of 40 percent. With a smaller wind-break on only the windward side, the houses still consumed 25 percent less fuel than similar unprotected homes. an Oklahoma study found that a tall evergreen hedge on the north side of a house reduced that household's fuel consumption by 10 percent during lighter winds and more than 30 percent during high winds.
The effectiveness of landscaping in reducing the cost of heating your home will depend on these factors:
If you live in a drafty home out in the open in the far north, for example, you'll receive the most winter time benefit from landscaping. You will benefit less if your home is well-sealed, sheltered by structures or trees, and located in a warm winter climate.
In all cases, whether you landscape to improve your home's efficiency in winter or summer,your landscaping will add value to your home and reduce your carbon foot print.
The climate in near your home is called its micro-climate. If your home is located on a sunny southern slope, for example, it may have warm microclimate, even though you live in a cool region. If you live in a hot and humid region, your home could still be situated in a comfortable microclimate due to dense shade and cool breezes.
Certain plants do well in your microclimate, while others will not thrive. This could depend on the type of soil, amount of shade, and local ground moisture. To help choose the correct plants, consult local expertise. These folks, such as master gardeners and landscape designers, can usually be found at local plant sales in the spring and summer. They are happy to answer questions for free during the event.