Windows
About Windows
Windows are the point in the building envelope where energy performance, comfort, and aesthetics converge - and in Canadian climates, a poorly specified window means cold drafts, condensation, and heating bills that never improve. Pro Materials supplies a full range of ENERGY STAR® certified replacement and new-construction windows engineered for Canadian climate zones: casement, bay, awning, double-hung, sliding, and specialty shapes with triple-pane Low-E glass options, argon and krypton gas fills, warm-edge spacers, and multi-point locking hardware. All window lines meet or exceed current NBC energy performance requirements and are rated for the appropriate ENERGY STAR climate zone. From Zone 1 southern Ontario to Zone 4 northern climates, we carry the specifications your project requires. Wholesale supply and professional specification support for contractors across Ontario and Western Canada.
Windows Buying Guide
Key factors to evaluate when specifying windows for your project.
How to Choose Energy-Efficient Windows for Canadian Climates
ER (Energy Rating) and U-Factor
The Canadian Energy Rating (ER) is the key metric for Canadian window performance - it balances solar gain against heat loss and air infiltration. An ER of 34 or higher qualifies for ENERGY STAR® Canada. For northern climate zones (Zone 3, 4), target ER 40+ and U-factor of 1.4 W/m²K or lower. U-factor measures heat loss; lower is better.
Glazing
Standard Canadian residential windows use double-pane Low-E with argon gas fill (ER 34–40). Triple-pane Low-E with argon or krypton provides ER 40–55+ and is strongly recommended for northern climates (Zones 3–4) and for homes targeting high efficiency. Low-E coatings can be spectrally selective - choose the right solar heat gain coefficient (SHGC) for your orientation: higher SHGC on south-facing windows maximizes passive solar gain in winter; lower SHGC on east and west exposures minimizes summer overheating.
Frame material
Vinyl frames have the lowest thermal conductivity and require no painting or maintenance. Wood-clad windows offer premium aesthetics with a wood interior and aluminum or vinyl exterior cladding. All our vinyl window lines include reinforced frame corners and multi-chamber profiles for structural integrity.
Window operation types
Casements and awnings crank outward and seal against the frame with a compression gasket - the best air seal of any operable window type. Double-hung windows are the traditional choice and easy to clean (tilt-wash sashes). Sliding windows suit wide openings. Awning windows are ideal for installations where a window is needed to remain open during light rain (bathrooms, kitchens).
Installation and flashing
Window performance in Canadian climates is equally about installation quality as product quality. Proper self-adhered flashing at the sill and jambs, a continuous air seal at the rough opening perimeter, and installation per the manufacturer's instructions are non-negotiable. Poorly installed ENERGY STAR windows underperform site-built windows that are well-installed.
Frequently Asked Questions
What is ENERGY STAR® certification for windows in Canada?
ENERGY STAR® Canada is a federal certification program administered by Natural Resources Canada. For windows, ENERGY STAR qualification requires meeting minimum Energy Rating (ER) thresholds that vary by climate zone: Zone 1 (Southernmost Canada): ER 25; Zone 2: ER 29; Zone 3 (most of Ontario, BC Lower Mainland): ER 34; Zone 4 (Northern Ontario, Prairies): ER 40. ENERGY STAR certified windows may qualify for provincial rebate programs - check with your provincial utility for current incentives.
Triple pane vs. double pane - is it worth the upgrade in Canada?
For most of Canada, yes - especially in Zone 3 and 4 climates. Triple-pane windows reduce heat loss by 30–40% compared to double-pane and virtually eliminate cold surface condensation on the glass. The payback period is typically 8–15 years in energy savings, and the comfort improvement - eliminating cold drafts near windows in winter - is immediate. For southern Ontario and the Lower Mainland (Zone 1–2), double-pane Low-E with argon is often sufficient and more cost-effective.
What window size do I need for building code egress requirements?
The National Building Code of Canada requires that all sleeping rooms have at least one window that provides an unobstructed opening of at least 0.35 m² (3.76 sq ft) with no dimension less than 380mm (15") width or height. The sill height must be no more than 1.0m (39.4") above the finished floor. These are minimum requirements - local jurisdictions may have more stringent requirements. Always confirm with the local authority having jurisdiction.
Can windows be installed in winter in Canada?
Yes, with proper precautions. Window and door installation in cold weather requires using low-temperature-rated spray foam and flashing tapes that maintain adhesion below -10°C. Standard flashing tapes and spray foam become ineffective below about -5°C. Keep product packaging warm until immediately before use. Most manufacturers specify a minimum installation temperature of -15°C for the product itself, but adhesive performance of sealants is the practical constraint.