A standard two panel sliding patio door costs $2,000 to $5,500 installed in the Capital Region. French doors run $2,500 to $6,500. Three and four panel systems run $4,000 to $12,000. Sill rot repair, which is common on patio openings, adds $300 to $1,500.
Patio doors are the largest single glass unit in most homes, which makes them both the biggest comfort variable and one of the larger line items in a window and door project.
Here is what they cost and what moves the number.
Installed cost by type
| Type | Vinyl | Fiberglass | Wood clad |
|---|---|---|---|
| Two panel slider, 6 foot | $2,000 to $3,500 | $2,800 to $4,500 | $3,500 to $5,800 |
| Two panel slider, 8 foot | $2,600 to $4,200 | $3,400 to $5,500 | $4,200 to $7,000 |
| Three panel slider | $4,000 to $6,500 | $5,000 to $8,000 | $6,000 to $10,000 |
| Four panel slider | $5,500 to $9,000 | $6,500 to $11,000 | $8,000 to $14,000 |
| French door pair | $2,500 to $4,500 | $3,500 to $6,000 | $4,500 to $8,000 |
| French door with sidelights | $4,000 to $6,500 | $5,000 to $8,500 | $6,500 to $12,000 |
What adds cost on a patio opening
- Sill and framing rot repair, $300 to $1,500. This is the most common addition, because patio door thresholds often sit at or near deck level where water collects.
- Subfloor repair at the threshold, $400 to $1,500, when water has been getting in for years.
- Widening the opening, $800 to $2,200, including a new header sized for the wider span.
- Internal blinds sealed between the panes, $300 to $800, which eliminates cleaning and cord hazards.
- Multipoint locking on a French pair, $300 to $900.
- Deck or threshold height adjustment, variable, where the existing threshold sits too low relative to the deck.
- Removing and reinstalling deck boards for access, $200 to $600.
Why sill rot is so common at patio doors
Patio door thresholds are frequently installed at or near the same height as the adjoining deck, which looks good and walks well but puts the threshold directly in the path of water, snow and ice. Snow piles against the door all winter, melts against the threshold, and any gap in the sealant or any missing sill pan lets that water into the framing. Because the area is covered by decking outside and flooring inside, nobody sees it until the floor near the door feels soft or the threshold moves underfoot. This is why we always quote patio door replacement with a note about rot repair, and why we open the area up and show you what is there before proceeding.
Is replacing a patio door worth it?
On an original aluminum-framed slider from before roughly 1990, it is one of the highest-value projects in the house. Uninsulated aluminum conducts cold straight through, so that door frosts, sweats and makes the whole room uncomfortable, and there is no repair for the material. Replacing it typically produces the most noticeable before-and-after comfort change of anything we do. On a fifteen-year-old vinyl slider that is merely hard to open, it usually is not worth it, because worn rollers and a dirty track are a two to four hundred dollar repair rather than a five thousand dollar replacement.
Ranges reflect typical Capital Region projects and are for planning only. Every Sundog quote is written, itemized, and free.
Frequently asked questions
How much does it cost to replace a sliding glass door?
A standard six foot two panel vinyl slider runs $2,000 to $3,500 installed in the Capital Region. Eight foot units run $2,600 to $4,200. Fiberglass and wood clad frames cost more, and three or four panel systems run $4,000 to $12,000.
Why did my quote include sill repair?
Because patio door thresholds often sit at or near deck level where water collects, and rot in the sill framing is extremely common at these openings. A good contractor flags it as a possibility up front and quotes it separately once the old unit is out and the actual condition is visible.
Is it cheaper to repair or replace a patio door?
Repair, by a wide margin, when the problem is operation. Worn rollers run $200 to $450, track repair $100 to $400, and weatherstripping $120 to $300. Replace when the glass has fogged, the frame has racked, or the frame is uninsulated aluminum, because none of those are repairable.
How long does patio door installation take?
One day for a standard two panel replacement in a sound opening. Add a day if the sill framing needs repair, which is common. Three and four panel units take longer because the panels are heavy and alignment across multiple panels is more involved.
Are internal blinds between the glass worth it?
For a patio door, often yes. They add $300 to $800 and they never need cleaning, never tangle, and eliminate the cord hazard that matters in a house with young children. The trade is that if the sealed unit ever fails, you replace the blinds along with the glass rather than separately.
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