Most misted or blown double glazed units can be fixed by replacing the sealed glass unit alone, without touching the frame, for a fraction of what a new window costs. For a standard casement window, expect an all-in price of around £130 to £300 for glass and fitting. Smaller panes often come in under that, while large picture windows or bay units climb higher.
Here’s the headline breakdown:
- Small window (e.g. bathroom or utility pane): roughly £120 to £200
- Standard casement window: roughly £130 to £300 all-in
- Large window or bay unit: roughly £350 upwards, sometimes reaching £900 for wide or multi-pane setups
Most glaziers also charge a call-out or minimum visit fee of £50 to £80, though many quote this as part of an all-in price rather than a separate line item.
Pro Tip: If your frame is in good condition, ask specifically for a “unit-only” quote and confirm whether the figure already includes the call-out. That one question stops a lot of billing surprises later.
How much does misted window repair cost by size?
Price depends heavily on the physical size of the failed unit and how many panes need attention. The table below reflects typical UK glazier pricing for glass-only sealed unit replacement, where the frame stays in place and only the double-glazed pane is swapped out.
| Window type | Typical cost (glass + fitting) | Notes |
|---|---|---|
| Small pane (bathroom, utility) | £120–£200 | Often close to the call-out fee alone |
| Standard casement | £130–£300 | Most common domestic job |
| Large window | £200–£500 | Depends on pane dimensions and glass spec |
| Bay window (per pane) | £300–£500+ | Angled units cost more to fabricate |
| Patio door panel | £250–£450 | Toughened safety glass usually required |
These figures track closely across independent UK sources. Checkatrade’s 2026 guide puts a small blown window repair at £100 to £200, a standard window at £200 to £325, and larger jobs from £350 upwards. MyBuilder’s price guide lists misted pane repairs commonly falling between £75 and £200, with the wider double glazing repair category spanning £50 to £500 depending on scope. MyJobQuote’s 2026 update confirms similar averages, generally £70 to £250 for glass-only work.
Three worked examples show how this plays out in practice:
A standard uPVC casement in a semi-detached house, single misted pane, no access issues: expect around £150 to £220 including the visit. A large picture window in a lounge, roughly 1.8m wide with a bespoke sealed unit: this often lands between £280 and £450, mostly down to the fabrication cost of a non-standard size. A three-pane bay window with one misted pane: because glaziers usually charge per pane and bay angles need custom-cut glass, a single pane swap here can reach £350 to £500, even though only one section has actually failed.
Compare that with full window replacement. Swapping the entire frame and glass on a standard casement typically runs into four figures once you factor in the frame, labour, and disposal, as covered in our guide to what double glazing replacement costs.
What factors change the price of a repair?
No two quotes look identical, and the gap usually comes down to a handful of variables rather than the glazier padding the bill. Understanding what changes affects the double glazing repair cost puts you in a better position to compare quotes fairly.
- Pane size and shape: bespoke or angled units cost more to fabricate than standard rectangular sizes.
- Glass specification: low-E coatings, argon gas fill, and acoustic laminate glass all add to the unit price.
- Frame material: uPVC is generally cheapest to work with; timber and aluminium frames often need more careful handling.
- Accessibility: upstairs windows, conservatories, or anything needing a ladder or scaffold tower adds labour time.
- Safety glass requirements: panes near doors or close to floor level must use toughened or laminated glass by regulation.
- Regional labour rates: London and the South East typically run higher than the Midlands, North or East Anglia.
Beyond the core unit swap, watch for extras: damaged handles or hinges (£20 to £80 each), Velux or roof window glass (often pricier due to access and specialist seals), and waste disposal fees for the old failed unit.
Pro Tip: If you have more than one misted window, ask your glazier to quote for all of them in a single visit. Combining jobs spreads the call-out fee across several panes and can shave a meaningful chunk off the total bill.
Should you repair or fully replace a misted window?
The right choice depends on your frame’s condition, your budget, and how long you plan to stay in the property. There are broadly three routes.
De-mist and reseal is the cheapest short-term fix, typically £40 to £80 per pane. A technician drills a small hole, clears the moisture, and reseals it. It does not restore the original factory seal or argon fill, so it usually lasts only two to five years before fogging returns.
Sealed unit replacement swaps the entire glass pane while keeping the frame. This costs roughly £150 to £350 per pane and restores proper thermal performance, typically bringing U-values back down to around 1.2 to 1.4 W/m²K on modern glass. This is the option most homeowners choose, and it delivers most of the benefit of a new window for a fraction of the price.
Full window replacement makes sense only when the frame itself is warped, rotten, or beyond economical repair.
| Option | Typical cost | Expected lifespan |
|---|---|---|
| De-mist and reseal | £40–£80 per pane | 2–5 years |
| Sealed unit replacement | £150–£350 per pane | 15–20+ years |
| Full window replacement | Several hundred | around 20 years |
Before deciding, run through a quick checklist: Is the frame free of rot, warping or draughts? Is the window under 20 years old? Do you need better thermal or acoustic performance beyond just clearing the fog? And does a cost-per-year calculation favour paying more now for a longer-lasting fix? If the frame passes muster, a sealed unit swap almost always wins on cost-per-year, even though the upfront figure looks higher than a quick reseal.
What happens during a misted window repair?
A typical sealed unit replacement follows a predictable sequence, and knowing the steps helps you judge whether a quoted timescale is reasonable.
- Call-out and measure – a technician visits, confirms the diagnosis, and takes precise internal measurements of the existing unit.
- Fabrication – the new sealed unit is manufactured to spec, which typically takes 5 to 10 working days for standard sizes and longer for bespoke shapes.
- Removal – on the fitting day, the glazing beads are carefully prised out and the failed unit is lifted from the frame.
- Fit and seal – the new unit is set into place, packed, and sealed to manufacturer standards.
- Finish and check – beads are refitted, the frame is cleaned, and the technician checks for a weathertight seal.
On-site work for a single standard pane usually takes 30 to 60 minutes once the fitter arrives with the fabricated unit. A quality replacement, properly fitted, should carry a manufacturer warranty of 10 years or more on the sealed unit itself.
Pro Tip: Ask whether the warranty covers the seal failing again, not just breakage. A genuine sealed unit guarantee should specifically name misting as a covered fault.
How do you get an accurate quote for the job?
Getting comparable quotes means asking the same questions of every glazier you contact.
- Is the price all-in, covering the unit, fitting, and call-out?
- What’s the lead time between measuring and fitting?
- What warranty applies, and does it cover future misting?
- Will the existing frame be kept, or does the job involve more?
- Is waste disposal of the old unit included?
Before the visit, take clear photos of the misted pane, note the window’s approximate age, and flag any visible frame damage. This speeds up the initial triage and often means a more accurate quote over the phone before anyone visits. As FENSA and GGF guidance recommends, get at least two written quotes and check the installer’s registration before booking anything. It’s also worth reading our tips on reducing double glazing repair costs before you commit.
- Photograph the misted pane from inside and outside.
- Note the window’s age and frame material.
- Get two or three written, itemised quotes.
- Confirm registration and warranty terms before booking.
A note from Cloudy2Clear Windows on repair vs replacement
We see the same mistake time and again: homeowners assume a misted window means the whole thing needs replacing, when in most cases only the glass has failed. Since 2005, Cloudy2Clear Windows has fitted and repaired double glazing across private homes and commercial premises throughout the UK, and glass-only replacement remains the most common, cost-effective fix we carry out when the frame is still sound.
The other mistake is choosing the cheapest reseal option without asking how long it’s expected to last. A £50 fix that fogs again within two years often costs more over a decade than a proper sealed unit swap done once. Get the frame checked properly before deciding, and don’t let a quick quote skip that step. Similar logic applies to any repair versus full-unit replacement decision, much like choosing to swap only a door slab rather than the whole frame when the frame itself is still structurally sound.
Book a glass-only repair with Cloudy2Clear Windows
Compared with a full window replacement, a glass-only sealed unit swap gets your window clear and thermally efficient again without the cost or disruption of ripping out the frame. Cloudy2Clear Windows carries out exactly this kind of repair as standard, alongside conservatory and Velux glass replacement, and handle or hinge repairs where the hardware has also failed.
Our teams work across several UK regions, and an on-site diagnosis is the quickest way to confirm your exact price rather than guessing from a phone description. We’re open Monday to Friday, 8:30am to 6:30pm, and a free estimate is the natural next step if you’ve spotted fogging on a pane at home. If you’re based near Milton Keynes, you can book a local assessment directly, or browse our glass replacement service to see the full scope of what’s covered before you call.
Sources
- Cost to Replace a Double Glazed Unit in 2026 | Axiom
- Cost of repairing double glazed windows (MyBuilder price guide)
- Blown Window Repair Cost 2026: Don’t Replace the Whole … (Checkatrade)
- Window Glass Replacement Cost Guide (2026 Update) (MyJobQuote)
FAQ
How much does it cost to fix misted windows?
A standard casement window typically costs £130 to £300 for a glass-only sealed unit swap, with small panes often cheaper and large or bay windows running higher.
Is it worth replacing misted windows?
Replacing just the sealed glass unit is usually worth it when the frame is sound, since it restores full thermal performance for a fraction of the cost of a new window and typically lasts 15 to 20 years or more.
Can misted double glazing be repaired?
Yes, either by de-misting and resealing the existing unit for £40 to £80 per pane as a short-term fix, or by replacing the sealed unit entirely for a longer-lasting result.
Are Cloudy2Clear Windows expensive?
Cloudy2Clear Windows quotes glass-only repairs in line with typical UK market rates, and because frames are reused wherever possible, most jobs cost significantly less than a full window replacement.
