OUTSIDE YOUR HOME

The outside of a house can strongly influence its energy bills.

For example, with careful landscaping, you can improve your privacy, raise the value of your property, add to your home's comfort, and - this may surprise you - cut your energy bills.

Planting the correct trees, shrubs, vines and groundcover can make your home both warmer in the winter and cooler in the summer.

In fact, the right type of tree can reduce your summer cooling costs by 20 to 40 percent.

Landscaping is just one of the ways to improve energy efficiency.

Anyone who has ever stood in the sun on a hot day will appreciate the value of shade.

But in the heat of summer, plants can keep your home cool in other ways besides offering shade: they create a cool microclimate that can dramatically reduce the temperature in the surrounding area by as much as nine degrees.

That's because during photosynthesis, large amounts of water vapour escape through their leaves, cooling the passing air.

The generally dark, coarse leaves also absorb solar radiation.

Deciduous trees - trees that drop their leaves each winter - offer one of the best ways to cut home cooling costs.

If you plant them on the northeast-to-southeast and northwest-to-southwest sides of your house, they can provide excellent protection from the summer sun by shading roof, walls and windows.

They also help to warm the house in cold weather. Because they lose their leaves in autumn, deciduous trees permit winter sunlight to reach the house, helping to heat it with solar energy.

In general, try to shade as much of the roof and walls of your home as possible.

If you need to choose between covering a small portion with dense shade, or a larger area with less dense shade, go for the larger area. That strategy will produce the best cooling results in summer.

It's also a good idea to plant trees so they shade the windows that allow summertime heat to enter your house.

If you're concerned about preserving your view, keep the sun's path in mind and plant one or two smaller trees slightly to the side of the window.

Other Shade Plants That Save Energy

In addition to trees, vines and climbing plants also act as effective sunscreens.

They are particularly good against south-facing walls where you probably don't want shade trees.

Planting a deciduous vine such as grape lets you enjoy the benefits of both summer shade and winter sun.

Just as evergreens can stop winter winds, carefully placed trees and shrubs will direct cooling summer breezes to your home.

Bushes planted a few feet away from the house will provide extra shade without obstructing cool air currents. Shrubbery will also reduce soil and wall temperatures and help to protect your home's foundation from root damage.

Shades and Awnings

Anyone sitting under a tree on a hot summer afternoon knows the cooling benefits of shade, but they may not realize just how effective it can be as a low-tech, low-cost way to cut their summer cooling bills.

Shading your home - with trees and other vegetation, or with exterior and interior shades - can reduce the temperature indoors by as much as 20 degrees on a hot day.

About 40 percent of the unwanted heat that builds up in your house comes in through windows.

Although both exterior and interior shades can control this heat gain, exterior shades - items such as awnings, louvers, shutters, rolling shutters and solar screens - are more far effective, since they block sunlight before it enters the windows.