Patio door quotes vary more than window quotes, and the spread is rarely about the door itself. Two homes on the same street can be $2,000 apart because one needs a new header and the other does not.
Typical installed ranges
- Sliding patio door, 6 ft, vinyl — $1,800 to $3,200
- Sliding patio door, 8 ft, fibreglass or hybrid — $3,000 to $5,500
- French door, double, in an existing opening — $2,800 to $6,000
- Lift-and-slide or multi-panel — $8,000 and up, often well up
Those figures assume the existing opening is reused. They cover the door, standard hardware, installation, disposal of the old unit and basic interior trim.
What actually moves the number
Changing the opening size. Going from a 6 ft to an 8 ft door means a new header, and in a load-bearing wall that means temporary support and often an engineer's sign-off. Budget $1,500 to $4,000 on top, plus permit time — this is the change most likely to require one.
Glass package. Triple glazing adds roughly 10–20%. On a patio door it is worth it in most of the country, because the glass area is large and it is usually the coldest surface in the room. Laminated or asymmetric glass is the upgrade to ask about if you are near a highway, a rail line or a flight path — unequal glass thicknesses cut noise far better than a third identical pane.
Hardware. Multi-point locking is the single upgrade that most changes how a patio door feels and seals over time. A single-point latch lets a tall slab bow, and that is where the draft comes from at −30 °C.
Sill and threshold detailing. Ask specifically about a sill pan and how the threshold drains. Patio doors sit at the wettest point of the wall and this is where a cheap installation shows up first, usually as a rotted subfloor three winters later.
Regional differences worth knowing
Prices in Vancouver and the Lower Mainland skew toward water management, because wind-driven rain matters more than deep cold. In Calgary and Edmonton the same money goes into thermal performance instead. In Quebec, a contract signed at your door is an itinerant-merchant contract under the Consumer Protection Act, which gives you ten days to cancel — useful to know before a deposit changes hands in Laval or Longueuil.
Do you need a permit?
Swapping a patio door into the same opening usually does not require one. Widening the opening almost always does, because it is structural. Rules differ sharply by municipality — some cities require a permit for any door replacement regardless of cost. Each of our city pages lists the local rule; check yours before ordering, since custom doors are non-returnable.
For the wider picture on glazing costs, see our window replacement cost guide, and if the door you are replacing has fogged glass, condensation explains whether the unit or the humidity is at fault.