Use the Window U-Factor Comparison(/tools/window-comparison) to compare specific U-factor / SHGC numbers from any of these windows side-by-side and see annual cost and payback vs a code-minimum baseline. Inefficient windows can account for up to 35% of a home's heat loss(/glossary/heat-loss), leading to higher heating bills and less comfort in Canada's cold climate. Upgrading to energy-efficient windows can reduce heat loss, improve comfort, and save you up to 12% on yearly utility bills. Here's a quick look at the best options: Key Features to Look For: - U-Factor: Lower values (e.g., 0.18 Btu/h·ft²·°F or less) mean better insulation. - Energy Rating (ER): Higher ratings (40+) ensure top energy performance. - Triple Glazing: Offers up to 50% better insulation than double-pane options. - Low-E Coatings: Reduces heat loss by up to 50%. - Gas Fills (Argon/Krypton): Improves insulation between glass panes. Top Window Types: 1. Fiberglass Triple-Glazed: Best for insulation and durability. ...