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Patio Door Cost in Ontario (2026): Sliding, French, 8-Foot and Triple-Glazed, Installed, and the Floor Under the Old One
Windows & Doors
What a Patio Door Costs Installed, and Why the Floor in Front of the Old One Is Part of the Price
The patio door is the biggest opening in most Ontario houses, the one that gets the most weather, the most feet, and the least maintenance, and the one most likely to have been leaking quietly into the subfloor for years. Here is what a new one costs installed, by type, with the repair line most quotes leave off until the old door is out.
The numbers
$3,2006-ft vinyl slider, installed
$4,2008-ft slider or French doors
$450allowance for a soft subfloor at the sill
$999the flyer door, which is $2,200 short of installed
| Patio door | Installed | Notes |
|---|---|---|
| Sliding, 6 ft (72 by 80), vinyl, double glazed | $3,200 | The standard. Screen, one-point lock, aluminum or composite sill. |
| Sliding, 5 ft (60 by 80) | $2,900 | Older bungalows. Same door, smaller. |
| Sliding, 8 ft (96 by 80), vinyl | $4,200 | Two panels at 48 in.; heavier; better rollers needed. |
| Sliding, 6 ft, triple glazed or fibreglass frame | $4,500 | No frost line on the rail in February. |
| French or garden doors, 6 ft, vinyl or steel | $4,200 | One or both panels swing. Two sets of weatherstrip. |
| French doors, fibreglass | $5,600 | The look, with a skin that does not dent. |
| Three-panel slider, 9 to 12 ft | $6,500 to $9,000 | Centre fixed, both ends slide, or one big slider. |
| Multi-slide or bifold, 12 ft, aluminum-clad | $11,000 and up | Header and threshold detail extra. Large doors. |
What installed means on a patio door
Old door out, including the frame, which is nailed through the flange and never comes out clean. The opening checked for level, because patio doors are 6 ft wide and a sill out of level by a quarter inch is a door that rolls shut on its own. The sill bedded in sealant or set on a sill pan with the ends turned up, which is the single thing that decides whether the subfloor is wet in five years. The frame shimmed, screwed, foamed, flashed at the head, caulked outside over backer rod. Interior casing matched or new. Two people, a morning if nothing is rotten.
The flyer price buys the door at the building supply. The $2,200 between it and installed is everything in the paragraph above, and the morning.
The floor under the old one
Stand on the floor just inside your patio door and bounce. If it gives, the subfloor is wet, and it has been for years: water running off the glass, under a sill that was set on shims and nothing else, into the plywood. Sometimes it is the plywood only ($450 to cut back and patch). Sometimes it is the rim joist, and that is a morning of carpentry ($1,200 or more) that the door installer may not do. Ask before the old door comes out, get the unit price on the quote, and read why it is always the patio door.
What moves the number
- Blinds between the glass: +$600. No dusting, no cord, and when the sealed unit fails in 20 years the blind goes with it.
- Foot bolt and upgraded handle: +$350. The standard slider lock is a hook into a thin strike. A foot bolt into the sill is the security upgrade.
- Low-E by orientation: $0. A west-facing patio door wants low-gain glass. Ask. Why.
- Brick: +$200. Stucco: +$300.
- Widening: $900 non-bearing, $2,400 bearing. Going from 5 ft to 6 ft or 6 ft to 8 ft is a header and a permit on most exterior walls. Permits.
- A step outside higher than the sill: $0 to $800. If the concrete pad or deck is above the threshold, water has nowhere to go but in. Sometimes the fix is a saw cut; sometimes it is the deck.
Where homeowners go wrong
- Buying the $999 door. Then finding out it does not fit the opening, has no sill pan, and nobody wants to install a door they did not sell.
- Letting the installer skip the pan. Ask what goes under the sill. The answer is sealant or a pan; “it is fine” is neither.
- Not budgeting the floor. The $450 is the usual surprise; have it in the number.
- French doors on a windy deck. Two swinging panels and a 50 km/h wind off the lake is a door that slams and a weatherstrip that gives up. Sliding or French.
Questions people ask
How much does it cost to replace a sliding patio door in Ontario?
$3,000 to $3,800 installed for a 6-ft vinyl door, before HST, in the same opening with a sound floor. Add $450 if the subfloor is soft, $600 for blinds in the glass.
How long does a patio door last?
Vinyl sliders, 20 to 30 years; the rollers and the lock go first and both are replaceable. The sealed glass unit, 15 to 25 years. The sill, forever if it was set in sealant and never if it was not.
Can a patio door be installed in winter?
Yes. Low-temperature foam and sealant, and an hour with the opening open, which is why installers charge the same and homeowners prefer May.
Price it with the floor in
The door calculator has every patio door above, the floor allowance, and the wall it goes into, and writes the scope with the sill pan on it so three installers quote the same door.
Sources and further reading
- Your rights when starting home renovations or repairs: Ontario government. The 10-day cooling-off period for contracts signed in your home, and what a contract has to say.
- JELD-WEN Canada: windows and exterior doors; the rough opening sheets and warranty documents are on the site.
