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myWindow Glass Replacement Cost
At a Glance
- The average cost of replacing blown windows is around £70.
- Double glazing glass replacement typically takes 30-60 minutes.
- A breakdown of how much misted window repair costs for different-sized units.
- A simple calculator for you to quickly estimate window glass replacement costs.
- An overview of what the job involves and advice from tradespeople on MyJobQuote.
- How to find a local window repair specialist.
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£70
Table of Contents
- How Much to Replace Double Glazing Glass?
- How Long Does Window Glass Replacement Take?
- What Affects the Cost of Replacement Double Glazed Units?
- What Extra Costs Are Connected With Blown Windows?
- What Causes Blown Windows?
- What's Involved in Replacing a Sealed Window Unit?
- Blown Double Glazing Checklist
- FAQs
How Much to Replace Double Glazing Glass?
Struggling with misted or blown double glazing? Need to know how much window glass replacement costs in 2026?
Replacing blown double glazed windows can often seem like an expense you could do without.
But, if the problem is simply misted up or cloudy double glazing, then you don't have to replace the entire window — just the double glazed unit itself, known as the "sealed unit", which is a cost-effective solution.
What exactly is a sealed unit?
Simply put, this is the glass component of your window, not including your window frame. Double or triple glazing is made up of two layers of glass (three for triple), a spacer bar, and an airtight seal between the panes of window glass.
So, when a window is "blown", this means...
- The airtight seal has been compromised
- Moisture has got between the panes of window glass
- There's persistent condensation, misting, or a generally cloudy appearance coming from within the window
Repairing a blown double glazed window is a common and affordable job that window fitters deal with. The average double or triple glazing replacement cost is between £55 and £195, but the exact price you're quoted will mainly depend on the size of the window.
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How much does it cost to replace blown double-glazed units in a typical two-bedroom terraced house?
"It depends on the size of the unit, but a normal-sized window costs about £50."
Window Glass Replacement Prices
In the table below, you'll find an overview of how much misted window repair costs for different-sized double glazed windows.
To identify your window size, here are some rough comparisons:
- Small bathroom/utility room window - 200mm x 400mm unit
- Standard small-size window - 500mm x 700mm unit
- Standard medium-size window - 800mm x 1000mm unit
- Standard large-size window - 900mm x 1200mm unit
| Window Size | Material Cost | Labour Cost | Total Cost |
|---|---|---|---|
| 200mm x 400mm unit | £25 | £30 | £55 |
| 500mm x 700mm unit | £34 | £40 | £74 |
| 800mm x 1000mm unit | £72 | £45 | £117 |
| 900mm x 1200mm unit | £95 | £50 | £145 |
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Window Glass Replacement Costs by Glass Type
When it comes to the cost of replacing your sealed unit, usually the biggest factor influencing the price of the window replacement will be the size. However, the type of sealed unit you need to replace will also have an impact on the final cost.
If you're replacing triple glazed units, or units with toughened or energy-efficient window glass, then these are likely to cost more than a standard double glazed unit. The table below shows typical costs for different types of replacement glass for uPVC windows.
| Window Glass Type | Typical Total Cost |
|---|---|
| Standard double-glazed unit | £55-£145 |
| Triple-glazed unit | £90-£220 |
| Toughened double-glazed unit | £80-£180 |
| Frosted or obscure double-glazed unit | £70-£170 |
| High-performance energy-efficient unit | £80-£190 |
| Conservatory side panel unit | £120-£250 |
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Conservatory window glass replacement is often more expensive simply because these panels are often much larger than standard house windows. Plus, additional features such as being toughened or having tinted glass may also be required.
Estimate Your Window Glass Replacement Cost
Looking for a project-specific cost for your glass replacement?
If you're not sure what local prices will look like in your area, why not try out our free replacement window glass cost calculator!
Simply fill in a few details, and get an accurate idea of local replacement glass costs in your area.
Window Glass Replacement Cost Calculator
How Long Does Window Glass Replacement Take?
An experienced tradesperson will take around 30 to 60 minutes to correctly replace window glass in a double glazed window.
As you can see from the table below, larger units will naturally take longer to replace. It's also worth mentioning that it would be more efficient to have multiple units replaced in the same visit, as travel and setup time will be spread across a single, larger job.
| Window Size | Estimated Duration |
|---|---|
| 200mm x 400mm unit | 30 mins |
| 500mm x 700mm unit | 40 mins |
| 800mm x 1000mm unit | 45 mins |
| 900mm x 1200mm unit | 50 mins |
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What Affects the Cost of Replacement Double Glazed Units?
There are various factors that will affect the window replacement cost if you have blown windows:
Number of Panes
If there's only one sealed unit with misty windows, this will be cheaper to repair in terms of materials compared to the cost of replacing multiple units.
However, bear in mind that the labour costs may not be too dissimilar if you have a small job to do.
This is because the glazier cost will include any set-up time, plus they may have a minimum fee.
Size and Style
Larger windows will be more expensive when you're looking at a home window repair, simply because they require more materials and more work.
It's also worth noting that some window styles, like replacing bay windows, generally have more glass, so these will be pricier.
Type of Glazing
Double glazing is common in the UK, and so many quotes on window glass replacement will default to this type of glazing.
Triple glazed windows are also becoming popular. The costs of blown window replacements will be higher because there's more glass involved.
Similarly, rooms like bathrooms often use frosted glass for privacy, which will also carry higher fees.
If there's something extra added to your windows, such as self-cleaning technology or tinting, you can expect the replacement window glass to be more expensive.
Material Costs
This links with the factors above, and the cost of glass is a major element of any window repair.
However, it's also important to recognise the smaller material costs that might go into the job, such as any work on the actual window frame itself.
Location
Finally, where you are in the UK will affect the prices you pay for window glass replacement.
Households in London and the south east will invariably pay more for this type of work due to the higher cost of living in those areas.
The top pane in my window is blown but the lower one looks fine. Do I need to replace the whole lot?
"No you don't need to replace the lot, just the one that has blown.
Only the glass will need to be replaced. It's worth taking a look at your other windows just in case — but unless it's really noticeable, it's not necessary."
Only the glass will need to be replaced. It's worth taking a look at your other windows just in case — but unless it's really noticeable, it's not necessary."
What Extra Costs Are Connected With Blown Windows?
There are some additional costs that might be involved with window pane replacement.
These will depend on your window's condition, and what type of agreement you have with your contractor:
Replacement Window Frame
Although many replacement double glazed units will not require frame replacement, there are some instances where it might.
If the window frame is damaged, it may make more financial sense to replace it at the same time as the blown window.
This may only be recognised when the window unit itself is removed, so it can be something of a hidden cost through no fault of your contractor.
You would essentially be replacing the whole window and, depending on the type and size of new window you need, you could expect additional costs of between £400 and £1,000+ per window.
Trims
The cost of new finishing trims for your windows will usually be included in the quote for double glazing glass replacement, but it's worth checking as it improves the overall aesthetic appeal of the windows.
If these will be an additional cost, they are not very expensive, typically between £10 and £30 depending on type and size.
Security Features
Checking whether your window handles are still effective is another quick task that could be useful when you're making any changes to your windows.
Replacement handles could improve the security of your home, as well as resolve any issues you might have had with opening and closing the units.
If you have new handles fitted at the same time as the replacement units, you could expect to pay an extra £40 to £150+, depending on the type of handle and locking mechanism required.
Access Equipment
Depending on which window units you need replaced, for the safe installation of the replacement units, access equipment may be required.
Replacing first and second floor window units, units in difficult-to-reach windows, or heavy and awkward conservatory panels may require some kind of scaffolding or hydraulic lift equipment.
Hiring a small access tower to replace window glass could cost £100 to £300, but more specialist access equipment or scaffolding could add an extra £300 to £1,000+ to your costs.
Waste Disposal
Typically, the disposal of old window units is included in your home window repair quote.
However, always check with your contractor that they plan on taking the old window away with them or you will need to arrange disposal yourself.
If they are going to charge you extra to get rid of your old sealed units, expect to pay between £20 and £50 to have them properly disposed of.
What Causes Blown Windows?
How do glazed windows become blown?
Let's take a look at some of the most common scenarios:
- Poor Window Installation - Without being fitted correctly to start with, there are going to be further issues later on.
- Failed Seal - If the seal between the two panes of window glass breaks, it allows moisture and condensation into the gap.
- Older Windows - When exposed to the elements, frames and sealant can deteriorate over time.
- Weak or Low-quality Glass - Using materials that are easily damaged is likely to compromise the end quality.
- Accidental Damage - If the glass or frame cracks, the seal can become disturbed and no longer work effectively.
- Using Harsh Abrasive Chemicals - Improper use of cleaning materials or chemicals can result in damage to the seal and frame.
While there can be a number of different explanations why double glazed units fail and become misty, the fact that the seal between the two panes of glass has failed is usually the most common reason.
How long do you expect double glazing to last before problems occur?
5 years or less
40 votes - 9%9% of votes
6 – 10 years
78 votes - 17%17% of votes
11 – 15 years
115 votes - 25%25% of votes
16 – 20 years
108 votes - 23%23% of votes
More than 20 years
125 votes - 27%27% of votes
466 votes
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What's Involved in Replacing a Sealed Window Unit?
Replacing a sealed unit is a relatively straightforward project, but a successful installation requires accurate measurements to be taken.
For the best results, we recommend hiring a local window repair specialist to get the job done efficiently and correctly.
The easiest way to find a window specialist near you is to use MyJobQuote. By entering a few details about your job, location, and budget, you'll be matched with local traders ready to help you with your misted windows.
It's free, easy, and there's no obligation to book.
This is what you can expect the process to look like when you hire a professional to replace window glass in your home:
Before the Job Starts
- Inspection & Measuring — Your window specialist will confirm the sealed unit has failed, check the condition of the existing frame, and take accurate measurements for your window glass replacement.
During the Job
- Removing the Old Unit — The glazing beads are removed, the failed unit is taken out, and the frame is prepared for the new unit.
- Installing the Replacement Unit — The new sealed unit is fitted, the glazing beads are reinstalled, and the window is checked to make sure it operates correctly.
After the Job
- Final Checks & Clean Up — The new unit is checked to make sure it is fitted securely with no movement or gaps, the work area is tidied, and the old sealed unit is taken away to be disposed of properly.
My mum’s bungalow has four double glazed windows with condensation between the panes. Is there a way to remove the condensation, or do the windows need to be replaced?
"The glass units have blown. It’s only a small job to replace the glass — there’s no need to replace the entire window. Replacing four units should take around an hour."
Blown Double Glazing Checklist
Before choosing a window repair specialist, here are the things you need to consider to make sure you find the best trader for your job:
- Have you been sent an itemised cost breakdown? Always ask for a breakdown so you know exactly what you're paying for.
- Does the contractor have experience with blown window replacement? Make sure the contractor is experienced in repairing and replacing blown glass for best results.
- Is waste removal included in the quote? Check to see if the contractor will remove any leftover waste or the old window, or if it's an extra cost you need to budget for.
- Is there a guarantee or warranty on their work? Before booking, ask if the contractor offers any guarantees on the window replacement and installation.
- Does the contractor have insurance? Make sure they're insured to carry out the work, ideally with Public Liability Insurance.
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FAQs
How Long Should My Windows Last before They Start Misting Up?
Many homeowners have no problems with their double glazing for 15 years or more. However, there are instances of blown double glazing happening within five years of installation - it depends on the quality of the installation and window.
Is Resealing a Window a Good Idea for Blown Double Glazing?
It's recommended you opt for a replacement unit rather than resealing a blown window. This is because window glass repairs will often simply remove the visible signs of the problem (e.g., cloudy windows) but may not fix the problem fully, leading to more problems later.
Can I Replace a Blown Sealed Unit Myself?
With the right set of skills, removing a blown double-glazed unit in order to replace a uPVC window is relatively straightforward.
If you're ordering a replacement unit directly from a supplier, you'll need to know precise details such as the size and thickness of the window glass, whether it’s toughened, and the type of glazing used.
If you're ordering a replacement unit directly from a supplier, you'll need to know precise details such as the size and thickness of the window glass, whether it’s toughened, and the type of glazing used.
Is a Blown Window Covered by Insurance?
You'll need to review your home's insurance policy to see if this is the case. In general, insurance companies won't pay out if it's just the seal that's broken, whereas if it's the window glass, then it may depend on what has caused the issue.
How Can You Stop Condensation Build-Up?
If you're concerned about blown windows caused by condensation, check the sealant around the glass and fill in any cracks with a silicone sealant. It's also recommended to keep the window clean, although it's best to use non-abrasive cloths and avoid harsh chemicals.
Does a Blown Window Repair Come with a Warranty?
The length of the warranty can vary depending on the company. If the entire window (including the seal) is being replaced, the warranty is most likely to last between 5 to 10 years. However, it's best to check with the window installer prior to starting work on the job.
