Standard Window Sizes in Canadian Homes: A Renovator's Cheatsheet
Too Long; Didn't Read
- There is no 'standard': "Standard" usually just means "Stock" sizes at Home Depot (e.g., 60x40).
- Common Widths: 24", 36", 48", 60" are the golden numbers.
- The "Brick-to-Brick" Rule: Always measure the masonry opening, not the old frame.
Answer First: In Toronto, the most common "stock" slider window size for bedrooms is 60" x 40" (Rough Opening). For basements, it's typically 32" x 16" or 36" x 24". But in 90% of retrofit cases, you should order Custom (sized to the 1/8th inch) rather than forcing a stock size into an old brick opening.
The Myth of "Standard" Sizes
If you walk into a big box store, you see rows of windows labeled "Standard." This is a lie. These are just sizes that builders bought in bulk 20 years ago.
In Toronto, especially in areas like Etobicoke, Scarborough, and North York with post-war bungalows, your "standard" hole in the wall has shifted, settled, or was never square to begin with.
The Truth Table: Common Toronto Rough Openings
We analyzed 500+ installs in the GTA. Here is what we actually find in the wild:
| Room Type | Window Style | "Stock" Size (WxH) | Real World Reality |
|---|---|---|---|
| Bedroom | Horizontal Slider | 60" x 40" | Often varies by +/- 1 inch. |
| Living Room | Picture / Fixed | 96" x 60" | Usually consists of 3 mulled units (Flanker-Fixed-Flanker). |
| Kitchen | Casement (Crank) | 36" x 36" | Over-sink windows often fight with the faucet height. |
| Basement | Slider | 30" x 16" | Old steel sash windows are notoriously non-standard. |
| Bathroom | Awning | 24" x 24" | Often frosted for privacy. |
Why "Stock" Sizes Cost You More
It seems cheaper to buy a $300 stock window off the shelf than a $500 custom window. But here is the math of installation:
- The Gap: If your hole is 62" and your window is 60", you have a 1-inch gap on each side.
- The Filler: You need to pack that with wood, spray foam, and massive caulking beads.
- The Trim: You now need custom aluminum capping to hide the mess.
- The Labor: The installer spends 2 extra hours framing it out.
Verdict: You saved $200 on glass and spent $400 on labor. Custom windows are made to the 1/8th inch, sliding right into the existing opening for a perfect seal.
How to Measure "Rough Opening" (RO)
Don't measure the glass. Don't measure the trim.
- Remove the Casing: Pop off the interior wood trim.
- Find the Studs: Measure from the jack stud on the left to the jack stud on the right. This is your Width.
- Header to Sill: Measure from the header beam above to the rough sill plate below. This is your Height.
- Deduct: For a custom order, we typically deduct 1/2 inch from width and height to check for squareness.
Modern Builds vs. Heritage Homes
- Post-War Bungalows (1950s): Simple rectangular openings. Usually standard brick sizing.
- Victorians (1800s): Nothing is square. Expect "Bow" tops or arches that require custom templates.
- New Construction: Often followed rigid 2-foot increments (24, 48, 72) to minimize waste.
Summary
Unless you are framing a new wall from scratch, ignore standard sizes. Order custom. It’s faster, seals better, and looks professional.
Planning a Renovation?
Don't guess your rough openings. We offer free on-site measurements to guarantee a perfect fit (to the millimeter).