Double glazing repairs: repair or replace?
Last reviewed: July 2026 · Fitted prices incl. VAT
Here is something window salespeople rarely volunteer: a huge share of “failed” double glazing does not need replacing. Misted glass means the sealed unit has failed — not the frame — and a glazier can swap just the glass for a fraction of the cost of a new window. This guide covers what repairs cost, and honestly, when replacement is the better call.
Common repair costs
| Repair | Typical fitted cost |
|---|---|
| Misted / blown double-glazed unit (glass only) | £75 – £200 |
| Window handle replacement | £40 – £90 |
| Hinge replacement (per window) | £60 – £120 |
| Rubber seal / gasket replacement | £50 – £130 |
| Window lock repair or replacement | £60 – £140 |
Prices assume a standard-size window with normal access. Very large panes, shaped glass or upper floors needing ladders/scaffold push costs toward the top of each band.
When a repair is the right call
- Misted or foggy glass, frames fine — replace the sealed unit only (£75–£200) rather than the whole window.
- Stiff or broken handles, locks and hinges — cheap hardware swaps that restore security and function.
- Draughts around the sash — new gaskets/seals usually fix this for under £130 per window.
- One problem window in an otherwise sound set — repairing one is far cheaper than being upsold a full house.
When replacement genuinely makes more sense
- The frames themselves have failed — warped, cracked or rotten frames cannot be meaningfully repaired.
- Multiple units misted across the house — if half your sealed units have failed, the rest are usually close behind; per-unit repair costs stack up fast.
- Single glazing — repairs cannot fix the physics; upgrading to double glazing transforms heat loss, noise and condensation.
- Very old uPVC (pre-2002, pre-Building Regs glazing standards) — modern A-rated units are a step change in insulation, and replacements must now hit a U-value of 1.4 W/m²K or better.
Get a number either way
Our estimate tool covers repairs as well as replacements — pick “a repair” and you will see typical costs for your region without giving out any contact details. If you would rather have firm quotes, we can arrange for vetted local firms to price both options so you can compare like for like.
Sources: repair cost bands compiled July 2026 from published UK glazier and installer price guides (Checkatrade, Which? Trusted Traders data), cross-checked against regional quote data.