Window replacement · Durham
Replacing windows in an Oshawa home: what to know first
Sometimes fixing it properly means a new window: the frame is soft, the sash won't close square, or the house still has single panes behind storms. Other times a new sealed unit or a new crank does the job for less; the windows overview covers those fixes. This page covers the first case: when to replace, how it's done, the rules that apply, and what belongs in a quote. We don't sell or install windows. We pass your request to an independent installer who works in Durham, then follow up so it doesn't stall.
- Straight talk on when a new window is due
- Permit, rebate and contract rules explained
- Quotes from installers who work in Durham
Is it done?
Signs it's time for a new window, not a new sealed unit
Fog between the panes isn't one of them on its own. A foggy window usually needs only a new sealed unit, and a stripped crank is a repair job. Replace when the frame itself is failing:
A soft, split or rotting frame or sill
If a screwdriver sinks into the sill, new glass won't stay sealed in that frame for long.
Drafts around the frame
Cold air at the edges, caulking that splits every spring. Winters here cross the freezing mark over and over, and that finds every tired joint.
Several failures at once
A fogged unit, a broken balance and a warped sash together. Past a point, fixing each part costs more than the window is worth.
Worn single panes behind storms
Common in Oshawa's older houses. Reglazing keeps them going until the wood sashes themselves are finished.
Two ways to do it
Insert (retrofit) versus full-frame replacement
Neither method wins every time; the old frame decides. Two quotes that look far apart are often one of each, so ask which you're being offered.
Insert (retrofit)
The sashes come out, the old frame stays, and the new window fits inside it. Less disruption, and trim often survives. The glass area shrinks a little, and the old frame must be sound and square.
Full-frame
Everything comes out to the rough opening, so rot can be fixed and the opening insulated and flashed properly. Full glass size, with more trim work inside and out.
Reading the label
Reading the label: ENERGY STAR Canada and NAFS performance class
Ask for both labels for the exact model being quoted.
ENERGY STAR certified
Canada has one national ENERGY STAR specification for windows, set as a maximum heat loss (the U-factor) or a minimum Energy Rating. There are no climate zones any more; anyone selling by zone is using old material.
NAFS performance class
Windows sold in Ontario are tested to the North American Fenestration Standard. The label grades air, water and wind resistance. The code sets a floor, and a wall facing the lake wind is a fair reason to ask about more.
Triple pane, honestly
Warmer inner glass and easier top ratings, but heavier and dearer. Compare certified ratings, not pane counts; good double-pane windows are certified too.
Permits
Permits in Oshawa: same size on a house versus new or larger openings, condos and apartments
The City's permit checklist lets you replace a window or door with one of the same size and type without a permit, for houses only. Everything else starts with a call to the City.
Same size and type, on a house
Usually no permit. Zoning still applies, and a heritage designation adds a step.
New, bigger or different openings
Needs a permit, including a basement window enlarged for bedroom egress.
Condos, apartments and storefronts
Outside the exemption, so check with the City. Condo owners also need the board's written approval first.
In Whitby, Ajax or Courtice, your own town or municipality issues permits, so its rules apply instead.
What moves the quote
What drives the price: size, style, frame, glass, install type and trim
Prices found online rarely describe a house in Durham. Yours depends on:
- The number and size of windows
- Style: slider, double-hung, casement, awning, bay or bow
- Frame: vinyl, fibreglass, wood or clad
- Glass: double or triple pane, low-E coatings, gas fill
- Insert or full-frame, and what's found behind the old window
- Brick, siding or stucco outside, plus trim and finishing
- Removal and disposal, and upper-floor access
A list of windows by room, rough sizes and your home's age is enough to start. The installer measures before anything is ordered.
Rebates
The provincial rebate and why it needs an energy assessment
There's no federal window grant right now; the federal Greener Homes program has closed to new applicants. Ontario's Home Renovation Savings Program pays a rebate per rough opening for ENERGY STAR certified windows and doors, generally through a home energy assessment with at least one other upgrade. Read its steps before you sign so the paperwork lines up, and confirm the current rules on its site.
It's for whole windows, so a new sealed unit won't qualify. Doors count too, so a tired patio door can join the same project.
Heritage homes
Heritage-designated homes: check before you change windows
If your house is designated, changes to its heritage attributes need Council approval; routine maintenance doesn't, and heritage permits carry no fee. Ontario gave municipalities until the start of 2027 to designate or drop older listed properties, so if your house is on the City's register, confirm its status first. Whitby's Brooklin and Werden's Plan districts have their own heritage permits.
Quotes and contracts
Quotes and contracts: estimates, HST and your 10-day cooling-off right
Windows aren't covered by Ontario's door-to-door sales restrictions, so salespeople can still knock. Sign at home and Ontario law gives you 10 days to cancel, counted from the day you get a written copy. A contractor also can't charge much above a written estimate without your agreement.
No ranking of installers is worth trusting. Look instead for a quote that shows:
An itemised price
Model, glass, install method, trim, and HST on its own line.
Labels by model
ENERGY STAR and NAFS ratings for the exact windows quoted.
Permit and disposal
Who applies to the City, and removal of the old windows included.
Questions
Window replacement questions
Explore your options
Before you commit to new windows
Installers who take these jobs cover Oshawa and the rest of Durham, including Whitby, Courtice, Ajax, Bowmanville and North Oshawa.
Tell us about the windows
How many windows, their rough sizes, and roughly when the house was built. We'll pass it to an installer in Durham who'll quote. If a sealed unit or a repair would do, a good one will say so.