Guide to choosing energy-efficient windows

Updated on March 29, 2024
4-minute read

Guide to choosing energy-efficient windows

Updated on March 29, 2024
4-minute read

Your windows are the biggest culprit for energy loss in your home! Older traditional windows let the sun heat your home in the summer and allow warm air to escape in the winter. Upgrading to energy-efficient windows is one of the best ways to save energy year-round.

Natural Resources Canada estimates that up to 25% of your heating and cooling is lost through inefficient windows. Replacing your existing windows with energy-efficient models may save up to 10% on your home's energy bills.

Windows can let energy through.

Insulated walls and roofs do an excellent job of keeping out the hot air in the summer and the cold air in the winter. Unfortunately, your heated air could be going right out the window!

Put your hand on your window. In the winter, it will feel cold. It will feel warm in the summer, even if the sun isn’t beaming down on it. This is because windows, doors and skylights allow energy to pass through them.

The heat, from inside or outside, can be absorbed and move through solid materials and the air around those materials. That is why single-pane, leaky windows always feel drafty and allow heat to escape. Fortunately, advanced energy-efficient window technology stops that process.

Man in baseball hat installing new window
Man in baseball hat installing new window
Man in baseball hat installing new window

What makes a window energy efficient?

Better frame material and technology.

Newer window frames made from vinyl or fibreglass are far more efficient than traditional metal window frames. These new window frames are filled with insulating foam or created as one solid piece with no air pockets. On the other hand, metal window frames conduct heat much more than other materials, making them less efficient.

Low-E glass

One of the most critical components of energy-efficient windows is glazing. Older windows are typically single-paned and have no coating. Highly efficient windows have a low-E glass coating on the surface. This coating reflects heat, which means it directs heat back inside in the winter and deflects the sun’s rays back outside in the summer.

Insulating gas

The space between the glass panes is filled with insulating gas. They use argon or krypton gas. These are safe, odourless, and clear gases with good insulating properties. Insulating pacer bars that hold each pane can also increase energy efficiency.

Double and triple-pane windows

Double and triple-pane windows allow for more insulation between each pane of glass. But, if your older or less efficient double-pane windows are not airtight, they allow heat transfer. Plus, they’re likely collecting condensation between the panes.

Double is good, but triple-pane is better. It gives you an extra layer of insulation and boosts thermal performance.

Window type and size

There are several types and styles of windows, and some are more efficient than others. For example, sliding windows are less efficient than casement or awning windows. These windows provide a better seal when closed.

Installing larger or more windows can also impact your home’s efficiency. They will allow more of the sun’s heat into the room, which is beneficial in winter. Just ensure you invest in triple-pane glass for those huge windows to maximize energy savings. 


Here in Canada, it's easy to shop for energy-efficient windows.

Just look for the ENERGY STAR® symbol! These certified windows have cleared stringent efficiency guidelines and can save up to 20% of energy compared to standard windows. Plus, you can choose products with the best rating for your geographic location and climate.

The best place to start shopping for energy-efficient windows is through a reliable and experienced window replacement company. Many will provide ENERGY STAR®-certified products manufactured specifically for Alberta’s climate.

They can help you choose the window type and style that meets your needs for energy savings, aesthetics, and value.

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