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Landscaping is one way to lower your energy bills while also beautifying your home. Trees, shrubs, vines, ornamental grasses, and hedges can help heat or cool your house, and they're a lot nicer to look at than a new furnace or air conditioner.

How to landscape your home for energy efficiency

A well-designed landscape can greatly reduce the amount of energy used for home heating and air conditioning. Many principles of energy-efficient landscaping are the same as those used in passive solar home design. By using energy-efficient landscaping techniques you can:[1]

• Drastically reduce your use of home heating fuel.
• Shield your home from cold winter winds.
• Significantly reduce your use of air conditioning.
• Shade your home from hot summer sun.

Landscaping in cold climates

In cold northern regions, the primary goal of energy-efficient landscape design is to use plantings and techniques that will keep your home warm in the winter and reduce your consumption of home heating fuel. To achieve this, you want to maximize your southern exposure and shield your home from cold winter winds using windbreaks. A windbreak creates a barrier that reduces and redirects the wind. Windbreaks usually consist of rows of trees or shrubs, but perennial or annual crops and grasses, fences, or other materials can also be used.[2].

For energy-efficient landscaping in cold climates:

• Don't plant tall evergreens to the south of your home where they'll block the low winter sun.
• Landscape with thickly planted trees, shrubs, and hedges to the east, north, and west of your house.[3]
• For relief from summer heat, plant a high-crowned deciduous tree near the south side of your house: it will shade and cool the house in the summer but won't block the sun in the winter.[3]
• Planting shrubs, bushes, and vines next to your house can trap layers of air between the plantings and your house, insulating it in both winter and summer. Plan for at least a foot of space between the mature plants and your home's siding.[4]
• If you're putting in a patio or driveway, locate it near your home's south wall. Heat-absorbing stone, brick, or concrete absorbs the sun's heat by day and radiates it toward your house at night, keeping it warmer.[3]

When planting a windbreak, keep the following tips in mind:

• Plant the windbreak the same distance from your house as the height of the mature trees or plants.[5]
• Fast-growing trees such as white pine and poplar can be used to get a windbreak off to a quick start, but since they're soft woods they'll break more easily in a high wind. Plant softwoods far enough from the house, with slower-growing hardwoods in their shadow: Eventually the hardwoods will dominate.[3]

Landscaping in hot climates

In a hot climate, cooling is the primary objective. Landscape plants can cool your home and reduce air conditioning costs: in fact, all plants help naturally lower the air temperature through a process called evaporative cooling. Plants release water through pores in their leaves. As warm air flows over the leaves, the water on the leaves' surfaces absorb the heat. This warmed water evaporates, leaving the surrounding air cooler.[6]

For energy-efficient landscaping in hot climates:

• Plant shade trees on the south side of your house to provide shade and natural cooling.[7]
• Plant trees on the east and west sides of your house to block the morning and afternoon sun.[7]
• Funnel hot, dry winds away from your home with bushes, palms, cacti, evergreen trees, or manmade screens. Plant windbreaks perpendicular to prevailing winds.[3]
• Plant large deciduous vines on a trellis, arbor, or pergola in front of or above windows, doors, and porches on the south and west sides of your house. Trellis slats can be angled to block out the sun's rays in the summer, but allow them in during the winter.[5][3]
• Shade your air conditioner to increase it's efficiency.
• Plant ground covers and shrubs around driveways and paved walkways. Pavement stores about 50 percent of the sun’s energy and reflects 40 percent as heat.
• If building a deck or patio, put it on the north side of your house.[7]

If you live in a hot, humid climate, a home snuggled under a stand of cooling, high-canopied palm trees is the perfect solution for energy-efficient landscaping. But what if you have solar panels, solar shingles, or a collector for a solar water heater on your roof? One solution is to shade most of the roof, and put the solar collectors on the remaining unshaded area. Another is to place them on the ground in an unshaded area.[8]

Neighborly considerations

In planning your energy-efficient landscape, don't forget your neighbors. The best place for your neighbor's windbreak or shade tree may be in your yard. If you live in close proximity to your neighbors, why not create a neighborhood landscaping plan and help each other out? On the other hand, planting trees that will grow high enough to block your neighbor's south-facing sun—especially if they have solar panels—isn't eco-friendly, or friendly period. In fact, in some cases it's downright illegal. California enacted the Solar Shade Control Act in 1978 to address just this issue.

Find it! Energy-efficient landscaping products

Landscaping your home for energy efficiency helps you go green because…

• Properly positioned trees can save up to 25 percent of energy consumption for home heating and cooling.[1]
• US Department of Energy (DOE) computer models show that just three properly placed trees will save from $100 to $250 in yearly energy costs.[1]
• Adding the right trees to an unshaded home can reduce summer air-conditioning bills by 15 to 50 percent.[1]
• One Pennsylvania study found that energy-efficient landscaping resulted in air-conditioning savings of up to 75 percent for small mobile homes. The DOE estimates that, on average, energy-efficient landscaping saves enough money in heating and cooling costs to return your initial investment within eight years.[1]
• The average home produces about 12,500 pounds of carbon dioxide each year. If 100,000 homes in the northern US planted a tree windbreak, decreasing their energy consumption by 15 percent, it would prevent the emission of 1.25 million pounds of carbon dioxide into the atmosphere every year.[5]

The Union of Concerned Scientists analyzed the ecological impact of the most common consumer actions and products and ranked "home heating, air conditioning, and water heating" fourth in its list of the "seven most harmful human activities" [to the environment].[9] US home heating systems pollute the air with more than a billion tons of CO₂ every year, as well as about 12 percent of the nation's emissions of sulfur dioxide and nitrogen oxides.[10] About 78 percent of single-family homes in the US use some type of air conditioning. Nationwide, air conditioning accounts for about 9 percent of our residential energy consumption. Using energy-efficient landscaping techniques can greatly reduce the use of fossil fuels used for heating and cooling our homes.[11]

Did you know?

• The shade from trees combined with their evapotranspiration (how they move and release water vapor) can lower the surrounding air temperature by as much as 9 degrees F (5 degrees C).[1]

External links

• US Department of Energy - Landscaping for Energy Efficiency
• University of Nebraska Extension - How Windbreaks Work
• Colorado State University Extension - Tree Placement: Right Plant, Right Place
• University of Florida Extension - Enviroscaping Learn tips to make your home cooler if you live in a hot, humid climate.