How Much Do French Windows Cost in 2026?
Check what new windows should cost, then get free quotes from local installers.
Your Estimate
£11,000 – £22,000- Supply only, you arrange fitting−£8,250
- Upgrade to triple glazing+£2,750
- Switch to aluminium frames+£5,800
- Switch to timber frames+£14,850
Now find out what yours actually costs
Installers covering your postcode will quote for your real windows, so you have something to check the benchmark against.
Get quotes for my 10 doorsPrices are estimates based on UK market averages for 2026. Actual costs vary by supplier, location and property. Always get 3 quotes before committing.
What a French window costs in 2026
A French unit is a pair of side-hung sashes that open from the centre with no fixed post between them, giving a clear, full-width opening. At window height it is a French window; running to the floor it becomes a French door, but it is built and priced the same way. The calculator above defaults to the French style (labelled French Doors), so count each pair as one window. A uPVC French window or door pair costs £1,100 to £2,200 fully fitted in 2026, with aluminium and timber rising from there.
French openings cost more than a single casement because there are two matched sashes, a flush meeting stile and hardware on both leaves. If you are replacing an actual door rather than a window, the door cost calculator carries the full front, patio and bifold ranges alongside French doors, and the master double glazing costs page sets the French row against the simpler styles.
| French window or door | uPVC | Aluminium | Timber |
|---|---|---|---|
| Per pair, fitted | £1,100–£2,200 | £1,490–£2,970 | £2,090–£4,180 |
Source: DGCC 2026 consensus (uPVC French); aluminium +35% and timber +90% as applied across the site. See the door cost calculator for door-specific ranges.
Which frame material suits a French opening
uPVC is the value choice and the most common, and it handles the wider opening well. Aluminium suits a modern rear extension where you want the slimmest frames around a garden view, which the aluminium window calculator prices. Timber is the period and conservation option, costed in the timber window calculator. If you only need a single opening rather than a pair, a standard casement will be cheaper, so price that too before you decide.
The verdict on French windows
A French opening is worth it where you want an unbroken, full-width view or a clear walk-through to a garden. For a plain window where a central post does not bother you, a casement does the same job for less.
Worth it French windows: worth it for a clear, postless opening to a garden or balcony.
French doors onto a patio are one of the few upgrades that genuinely change how a room feels, so they are usually money well spent. Just be clear with yourself whether you want a window or a door, because the floor-length version needs a proper threshold and that affects both the price and the fitting.
Double Glazing Cost Calculator Team
Frequently asked questions
A uPVC French window or door pair costs £1,100 to £2,200 fully fitted in 2026. Aluminium runs roughly 30 to 40% higher and timber roughly 60 to 110% higher for the same opening.
Both are a pair of side-hung sashes that meet in the middle with no central post. A French window sits on a sill at normal window height, while a French door runs to the floor and you walk through it. They are built and priced the same way.
A French unit is two opening sashes that meet without a central mullion, so it needs a rebate, a flush meeting stile and matched hardware on both sides. That extra joinery and the wider opening push it above a single casement.
If you are replacing a door rather than a window, use the door cost calculator, which carries the full uPVC, composite and aluminium door ranges. The French style here covers the window-height version on the same pricing basis.