What double glazing repairs cost in 2026
Most double glazing problems do not need a new window. The commonest fault is a misted or blown unit, where the seal between the panes has failed and condensation appears inside the glass. Fixing that means replacing the sealed unit alone, £55 for a small pane up to £145 for a large one, while the original frame stays put. Other repairs are similarly modest: a new handle, a pair of hinges, or a specialist reseal. The calculator above prices a full replacement so you can compare, but the table below is what a targeted repair actually costs.
| Repair | Typical cost | Notes |
|---|---|---|
| Replace a misted/blown sealed unit (single pane) | £55–£145 | Depends on pane size; the most common repair. |
| Replace the unit in a whole window | £100–£850 | Small £100–£200, standard £200–£325, large or bay £350–£850. |
| Reseal double glazing (per window) | £50–£100 | Specialist resealing where the gasket or seal has failed. |
| Replace a window handle | £45–£150 | Parts and labour; a quick job on most uPVC frames. |
| Replace window hinges | £100–£250 | Parts from around £27.50 a pair plus labour. |
| Replace a uPVC frame | £250–£750 | When the frame itself, not just the glass, has failed. |
Source: Checkatrade (Blown window repair 2026; Window hinge repair 2026), MyBuilder, homerepairguide.co.uk (2026) and Cloudy2Clear. Prices vary with window size and access.
Repair or replace?
The decision turns on the frame, not the glass. If the uPVC frame, sill and mechanism are sound and only the sealed unit has misted, repair wins every time: £55 to £145 against several hundred for a new window. Where it tips toward replacement is when the frames themselves are failing, the hardware keeps breaking, or several units have blown at once across an ageing installation. At that point you are spending repair money repeatedly on windows near the end of their life. Our guide to how long double glazing lasts helps you judge where your windows sit, and is double glazing worth it works through the wider replacement decision.
If replacement is the answer, price it properly rather than guessing. For the most common frame, run the uPVC window calculator, or for a period home use the sash window calculator. A like-for-like replacement of a single failed window is often closer to a repair in cost than people expect.
The verdict on repairs
For a misted unit on a sound frame, repair is a clear best buy. Replacement only earns its place when the frames or hardware are failing across the house, not just the glass.
Best Buy Repair a misted unit on a sound frame: a clear best buy at £55 to £145.
It depends Whole-window replacement: it depends on whether the frames and hardware are also failing.
Nine times out of ten a foggy window is a blown unit, not a dead window. I swap the sealed unit, the frame stays, and the customer pays a fraction of a replacement. Only start talking about new windows when the frames are going or half the house has blown at once. Do not let anyone sell you a full house when a few units have failed.
Tom Bradley, FENSA-registered installer
Frequently asked questions
It depends on the fault. Replacing a single misted or blown sealed unit costs £55 to £145, resealing a window £50 to £100, a new handle £45 to £150 and new hinges £100 to £250. A whole-window unit replacement ranges from £100 for a small window to £850 for a large bay.
Repair is almost always cheaper if the frame is sound and only the glass has misted, because you replace just the sealed unit for £55 to £145 rather than the whole window. Replacement makes sense when the frames are failing, the hardware keeps breaking, or several units have blown at once.
Misting means the seal between the panes has failed. Replacing that single sealed unit costs £55 for a small pane up to £145 for a large one, and the original frame stays in place. It is one of the most cost-effective repairs in the home.
Yes, in most cases. If the uPVC frame is still solid and only the glazing has failed, an installer can fit a new sealed unit into the existing frame. You only need a full replacement when the frame, sill or opening mechanism is beyond economic repair.