Window replacement is one of the most impactful and most confusing renovation decisions for Ontario homeowners. Here’s the 2026 clarity guide.
When to replace:
- Condensation between panes (seal failure, insulating value lost)
- Visible drafts at frame or sill
- Single-pane glass (no meaningful insulation)
- Rot in frame (wood windows) or visible deterioration
- Won’t open or lock properly
Performance specs that matter:
U-factor: Measures overall heat loss. Lower = better insulating. Ontario minimum recommendation: 1.4 W/m²K. Better: below 1.0. Best: below 0.8 (triple-pane).
Low-E coating: Reduces radiant heat transfer. Standard on all Energy Star windows in Canada.
Gas fill: Argon (standard) or krypton (premium) between panes. Both improve insulating performance significantly vs. air-filled.
Solar Heat Gain Coefficient (SHGC): In cold climates, higher SHGC on south-facing windows can improve passive solar gain — a benefit, not a drawback.
Material options:
Vinyl: Dominant choice in GTA renovations. Low maintenance, reasonable performance, competitive price. Limitations: can’t be painted (colour selection at time of order), perceived as less premium in character-sensitive markets.
Wood: Premium aesthetics. More maintenance. Required in heritage designations and character-sensitive markets.
Fibreglass: Premium performance and durability. Closest to wood in appearance. Higher cost.
Cost ranges (GTA, 2026):
- Standard double-hung vinyl: $600–$1,200/window installed
- Premium casement: $900–$1,800/window
- Full home (15–20 windows): $14,000–$32,000
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