• Home & Living

Siting and Design: Landscaping for Energy Efficiency



A well-informed and well-designed home admits low-angle winter , rejects overhead summer , and minimizes the cooling effect of winter winds. If you are building a home, pay attention to its orientation.

In the northern hemisphere, it is usually best to bring home long axis in an east-west direction. The home’s longest wall with the most window area should face south or southeast. The home’s north-facing and west-facing walls should have fewer windows because these walls generally face winter prevailing winds. North-facing windows receive little direct sunlight.

To cool the south and west sides of the home, reduce paved areas, plant shade trees, or add a trellis.

To cool the south and west sides of the home, reduce paved areas, plant shade trees, or add a trellis.

You may be able to design and orient your new house to maximize your homepage natural advantages and mitigate its disadvantages. Notice your website exposure to sun, wind and water. Also note the location and proximity of nearby buildings, fences, water, trees and pavement, and the possible climatic effects. Buildings provide shade and . Fences and walls block or channel the wind. Water bodies moderate temperature but increase humidity and produce glare. Trees provide shade, , or wind channels. Pavement reflects or absorbs heat, depending on whether its color is light or dark.

During the summer, tall spreading trees planted close to the home shade the roof. Broad, shorter trees on the west side block afternoon solar heat. A windbreak on the northwest side can shield the home from prevailing winter winds.

During the summer, tall spreading trees planted close to the home shade the roof. Broad, shorter trees on the west side block afternoon solar heat. A windbreak on the northwest side can shield the home from prevailing winter winds.

If your home is already built, inventory its comfort and energy problems, then use the following ideas to help minimize these problems.

Shading

Solar shading pass through windows and being absorbed through the roof is the main cause of air conditioner use. Shading is the most cost effective way to reduce solar heat gain and cut air conditioning costs. Using shade effectively requires you to know the size, shape and position of the moving shadow that your shading device casts. Remember that homes in cool regions may never over heated and may not require shading.

Trees can be selected with appropriate sizes, densities and shapes for almost any shading application. To block solar heat in summer but let much of it during the winter, use deciduous trees. To provide continuous shade or to block heavy winds, use evergreen trees or shrubs.

Deciduous trees with high, spreading crowns (ie, leaves and branches) can be planted to the south of your home to provide maximum summertime roof shading. Trees with crowns lower to the ground is better suited to the west, where shade is needed from lower afternoon Sunday angles. Trees should be planted on the south by the solar heated homes in cold climate, because the branches of these deciduous trees will block some winter Sunday.

A 6-foot to 8-foot (1.8 meter to 2.4 meter) deciduous tree planted near your home will begin shading windows the first year. Depending on the species and the home, the tree will shade the roof in 5 to 10 years. If you have an air conditioner, be aware that shading the unit can increase its efficiency by as much as 10%.

Trees, shrubs and ground cover plants can also shade the ground and pavement around the home. This reduces heat radiation and cools the air before it reaches your home’s walls and windows. Use a large bush or row of shrubs to shade a patio or driveway. Plant a hedge to shade a sidewalk. Build a trellis for climbing vines to shade a patio area.

Vines can shade walls during their first growing season. A lattice or trellis with climbing vines or a planter box with subsequent vines, shades the home’s perimeter while the procedure cooling breezes to the shaded area.

Shrubs planted close to the house will fill rapidly and begin shading walls and windows within a few years. However, avoid allowing dense foliage to grow immediately next to a home where wetness or ongoing moisture problems. Well built home in wet areas allow winds to flow around the home, keep the home and its surrounding soil reasonably dry.

Properly selected and placed evergreen trees and shrubs can shelter the home from winter winds and reduce heating costs.

Properly selected and placed evergreen trees and shrubs can shelter the home from winter winds and reduce costs.

If south winds are a problem in the winter, plant evergreens far enough away to lift winds without shading the home.

If south winds are a problem in the winter, plant evergreens far enough away to lift winds without shading the home.

Wind Protection

Properly selected and placed landscaping can provide excellent wind protection, which will reduce heating costs considerably. Moreover, these benefits will grow with trees and shrubs mature. The best windbreaks block wind close to the ground by using trees and shrubs that have low crowns.

Evergreen trees and shrubs planted in the north and northwest of the home is the most common type of windbreak. Trees, bushes and shrubs are often planted together to block or impede wind from ground to trees. Or, evergreen trees combined with a wall, fence or earth Berm (natural or synthetic walls or raised areas of soil) can deflect or lift the wind over the home. Be careful not to plant Evergreen too close to your home’s south side, if you rely on heat from the winter Sunday.

A windbreak will reduce wind speed for a distance of up to 30 times the windbreak’s height. But for maximum protection, plant your windbreak at a distance from your home in two to five times the mature height of trees.

If snow tends to slide in your area, plant low shrubs on the Windward side of your windbreak. The shrubs will shed snow before it blows next to your home.

In addition to more distant windbreaks, planting shrubs, bushes and vines next to your house creates dead air to insulate your home in both winter and summer. Plant so there will be at least 1 foot (30 centimeters) of space between full-grown plants and your home’s wall.

Summer wind especially during the night may have a cooling effect if used for home ventilation. But if the wind is and your home is air conditioned all summer, you may want to keep summer winds from circulating near your home.