Choosing Windows for Ontario’s Cold Winters
Compare U-factor, Energy Rating, air leakage, glazing, installation and room exposure—not just the number of panes.
Start with U-factor and air leakage
Lower U-factor generally indicates less heat transfer, while air leakage relates to drafts through the window assembly. Compare both with the complete product and installation details rather than relying on marketing language.
Match glazing to orientation and use
Low-E coatings, solar heat gain, glass spacing and double- or triple-pane construction affect comfort differently on a sunny south-facing room, a shaded north wall or a cold bedroom.
Installation is part of winter performance
Sill support, shimming, insulation, perimeter air sealing and exterior water management all matter. A strong product rating cannot compensate for a poorly prepared opening.
Planning a Window or Door Upgrade?
Tell us what you are considering and we will help you identify the next useful step.