Decorating & Design

November 4, 2009

Updating Windows To Save Energy

Windows provide beautiful views as well as warm sunlight into your home, but ill-fitting or single-glazed windows may be letting valuable heat (or cold) escape. In fact, they can account for 10 to 25 per cent of your heating bill. Weather stripping operable windows, caulking around window frames and using heat-shrinkable plastic in winter are all affordable ways to stop drafts. At some point, however, you may want to invest in better windows. After all, energy efficiency will lower your heating and cooling bills, as well as help reduce greenhouse gases. Here’s what you need to know.

Buying New Windows

Before investing in new windows, book a home-energy audit to identify whether in fact your windows could be more energy efficient, in addition to other energy saving opportunities around your home.If your energy audit indicated that replacing your windows is a good idea, or if your windows are 15 years old or older, this may be a good time to upgrade. (Assuming that reglazing and refitting aren’t better options.) If you choose to replace them, ideally you should look for high-performance windows with low-E coatings, inert gas fills, and better edge spacers and frames, according to Canada’s Office of Energy Efficiency. Low-E coatings, for example, help windows take solar energy from outside while retaining heat inside. Argon and Krypton gas fills between glazings also help reduce heat loss from inside. Ultimately, high-performance windows can reduce your space heating costs by nine to eighteen per cent, as well as lower your cooling costs in summer.

Before making a decision, inspect samples and take into account a variety of factors, such as whether the window is fixed or operable, the glazing type, frame materials, energy rating and warranties. You’ll also want to visit the ENERGY STAR web site, to ensure that the new windows are qualified for your climate zone.

Other Considerations

In addition to choosing high-performance windows, you’ll also want to consider how many windows to use, and where to place them. Keep in mind that larger windows tend to perform better than multiple small ones, for instance. You may also want to minimize your number of south and west-facing windows, or at least keep curtains drawn on these during the hot summer months. (During the winter, open blinds during the day and close them at night.)

Have your windows installed according to the manufacturers’ directions by a trained professional. Be sure to keep the ENERGY STAR labels on the windows if you plan to do a post-retrofit home-energy audit, or retain a copy of an invoice indicating the window brand/product name, the NRCan model reference number or the manufacturer’s model code, as well as the climate zone for which the windows, doors or skylights may qualify for government rebates.