COST GUIDES
What is the cost of repairing misted double glazing?
Updated 05/26
When moisture gets trapped between two double glazed glass panes, it causes the window to mist up. Read on to find out the cost of replacing misted double glazing units, including how you may be able to get them replaced for free.
Fast Facts
The average cost to replace double glazing is £250 overall
Expect to pay in the region of £225 - £275 per unit
Double-glazed windows that open cost more to replace than fixed ones
As well as looking unsightly, misted windows are a sign that the double glazing has not been sealed and insulated correctly. Replacing a failed or blown unit will prevent heat from escaping and bills from rising.
If you've spotted a few windows in your property with this issue, it's worth hiring a professional to install a replacement.
In this guide we provide an overview of the average costs and key considerations for the job.
How much do replacement double glazed units cost?
| Type and size of window | Price - Range low | Price - Range high | Average Cost (+VAT) |
|---|---|---|---|
| Small single-glazed fixed sash window | £115 | £165 | £140 |
| Small single-glazed opener sash window | £150 | £200 | £175 |
| Standard double-glazed bay fixed window | £225 | £275 | £250 |
| Standard double-glazed bay opener window | £275 | £325 | £300 |
| Last updated: May 2026 Our costs are ballpark averages - get a local tradesperson to quote now | |||
The average replacement double glazing window cost is £250, with prices per unit typically falling within the region of £225 - £275.
Prices are calculated per panel.
Before getting a quote, check whether any other units in your home are starting to show signs of mist. If there are a couple, it may be the case that none of your units were installed correctly. Professional window replacement companies may offer a reduction if multiple units need replacing at one time.
Find a glazier near you to replace your double glazing
Check - your windows may still be under warranty
Before reaching out to an expert for a quote, we recommend checking the double glazing paperwork you would have received upon installation.
The windows may still be under warranty. If that's the case, you can make a claim for them to be replaced for free on the grounds of defective windows.
Many installers offer warranty periods that last for several years, so it's certainly worth having a look.
What's included in a misted double glazing replacement quote?
When you get a quote from a window professional for replacing your blown double glazing units, you can usually expect it to include the cost of:
Labour
Replacement glass panes
Any other parts, such as locks and hinges
Cleanup and disposal of the old glass
Additional costs to budget for
Be prepared to pay a little more for:
Large or uniquely-shaped windows
Windows on period properties
Transportation and parking
Access equipment, if the unit is especially hard to reach safely
Extra coatings on the glass
VAT
Wondering if you need energy efficient windows? Whatever your need, from double glazing repairs, to finding an installer, we've got you covered. Even if you can't choose between window types.
How much does it cost to repair misted double glazing?
Depending on the extent of the damage, as well as how many windows are blown, it can be more economical to get your window repaired rather than replaced entirely.
To repair a single pane of glass in a misted or blown window, it costs around £55- £145 per pane.
To learn more, take a look at our guide to blown window repair costs.
Blown window repair: Cost breakdown 2026
Suffering from blown windows in your home? Getting them repaired can be a lot more straightforward than you might think. Here, we’ll explore how much blown window repair typically costs.
What affects the cost of replacement double glazed panels?
Replacing a failed or blow unit isn't just a question of aesthetics, it's essential in enhancing the energy efficiency of your property.
A specialist window fitter will calculate the cost of replacing misted double glazing units by factoring in the following information:
Type of window - As you may expect, a larger window such as a double-glazed bay opener window will cost more to replace than a small fixed single-glazed sash window (priced at an average of £300 and £140 respectively).
The number of units - The more units that require replacing, the higher the total cost - although, window fitters will typically offer a discount if there are multiple units that need replacing.
Location - Prices will often be higher in London, but remember to shop around to compare quotes before hiring a professional.
Try the job estimate calculator
You can get a better idea of how much you need to budget for your misted double glazing replacement by using our job estimate tool.
Type in a few details about your windows, and the calculator will give you an approximate quote using Checkatrade data. Why not give it a go?
Job Estimate Calculator
How do I know if I have blown double glazing units?
It's simple - you can tell your double glazing has blown if you can see water droplets, cloudiness, and condensation between the panes of glass.
There should be no moisture whatsoever between panes of double glazing. If you see water or condensation, that means the seal has failed, and it means your double glazing is no longer effective.
In other words, it's no longer providing the insulation you need!
Once your double glazing has misted or blown, it's vital to get it repaired or replaced by a window repairperson as soon as you're able to.
Find a glazier for your blown double glazing replacement
Ready to get started replacing your blown double glazing? Checkatrade is the perfect place to start your search to find a window fitter near you.
Just enter your postcode to begin comparing your options, or try our request-a-quote feature to hear back from glaziers who cover your local area.
Find a glazier near you to replace your double glazing
FAQs
When mist starts to form on a double-glazed window, it's a sign that water has managed to enter the air gap between both panels. In most cases, this is due to improper installation.
The problem in most cases of misted windows is that the double-glazing units themselves have not been installed correctly in the first place. This allows condensation to accumulate between the panes. To prevent this from happening in the future, it's best to hire a professional who can ensure the job is carried out properly.
A misted window isn't just unsightly. If the seal is not tight enough, heat will escape through the gap, increasing the cost to heat your home. To keep your bills down and your property more energy-efficient, we recommend calling in a double glazing installer to replace the failed units.
The usual and most effective way to repair misted double glazing is to replace one or both panes of glass.
There are other methods too, which may involve drilling a small hole and adding a desiccant to absorb the moisture.
Misted or blown double glazing is normally caused by improper installation. It can also simply mean that the airtight seal around the glass panels has deteriorated, especially if the windows are old.
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