Windows, doors and skylights


Windows, doors and skylights can add character and style to a home, but they can also be a significant source of heat loss and discomfort.

When buying a new home or replacing windows, doors or skylights for an existing dwelling, use the ENERGY STAR symbol to help you select models that will save you money and keep your house comfortable year-round.

Professionally installed ENERGY STAR qualified residential windows, doors and skylights can reduce your annual heating and cooling costs by up to 16 percent. They reduce or eliminate cold drafts and condensation on the glass in the winter and keep hot air out and cool air in during the summer.

What makes the difference? ENERGY STAR qualified windows, doors and skylights have many of the following features:

  • double or triple glazing with a sealed insulating glass unit
  • low-emissivity (low-E) glass
  • inert gas, such as argon or krypton, in the sealed unit
  • low-conductivity or “warm edge” spacer bars
  • insulated frames, sashes and door cores
  • good airtightness

ENERGY STAR qualified windows, doors and skylights are certified by an accredited independent agency for their energy performance and quality.

Climate conditions vary from one part of Canada to another – and so do the qualification criteria for ENERGY STAR for windows, doors and skylights. To qualify, these products are tested for their thermal performance and airtightness. The colder the climate, the tougher the qualification requirements.

But do not worry – ENERGY STAR does all of the technical work for you, making it easy to identify products that will suit your climate. Simply consult the ENERGY STAR climate zone map to find the zone where you live (see the map on this page). Then check the ENERGY STAR label to make sure the product qualifies in your zone. To save even more money and energy, buy a product that qualifies for ENERGY STAR in a colder zone (Zone A is the mildest and Zone D is the coldest).

ENERGY STAR Climate Zone Map

map of zones

ENERGY STAR Climate Zone Map

Text version

Climate zone map divided into four zones.
Zone A, in light green, in south-western B.C. and Vancouver Island.

Zone B, in dark green, central and south-eastern B.C., south-western Alberta, extreme southern Saskatchewan, central and southern Ontario, south-western Quebec, all of the Maritimes and Newfoundland except for the Avalon Peninsula.

Zone C, in light blue, southern and central Yukon, extreme south-western N.W.T. northern B.C., central and northern Alberta, all of Saskatchewan except for the extreme south, all of Manitoba, most of northern Ontario except for the far north, central Quebec, southern and central Labrador and the Avalon Peninsula.

Zone D, in purple, in the northern Yukon, all of N.W.T. except for the extreme southern portion, all of Nunavut, extreme northern Ontario, northern Quebec and northern Labrador

ENERGY STAR labels for windows, doors and skylights come in various formats, each of which indicates the climate zone (or zones) where the product is qualified. To ensure an energy-efficient purchase, look for any of these labels in dealer showrooms, on Web sites or in product literature.

If your old windows are single- or double-glazed without low-E and argon gas but are in good condition (i.e. they do not need to be replaced), you may be able to add a storm window to get an extra layer of protection. Adding a storm door can also improve airtightness around entrances.

Examples of labels for windows, doors and skylights

Canada blue zone
U.S blue zone
zone label

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