Window Glass Replacement Cost

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. Your double glazed window is made up of two layers of glass (three for triple), a spacer bar, and an airtight seal between the panes of glass.

So, when a window is "blown", this means...

• The airtight seal has been compromised
• Moisture has got between the panes of 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 window glass 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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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

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 window glass replacement cost calculator!

Simply fill in a few details, and get an accurate idea of local window glass replacement costs in your area.

Window Glass Replacement Cost Calculator

How Long Does Window Glass Replacement Take?

An experienced tradesperson will take about an hour to correctly replace the glass in a double glazed window.

What Causes Blown Windows?

How do glazed windows become blown?

Let's take a look at some of 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 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.

One of the most common reasons why double glazed units become misty is because the seal between the two panes of glass has failed.

If this happens, then you do not need to replace the entire window, including the frame.

You can, in fact, simply replace the double glazed unit itself. Alternatively, there are specialist companies that can repair the double glazed units by removing any moisture and resealing the window.

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

73 votes - 16%16% of votes

11 – 15 years

111 votes - 25%25% of votes

16 – 20 years

103 votes - 23%23% of votes

More than 20 years

118 votes - 27%27% of votes

445 votes See results Hide results

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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 pane 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 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.

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.

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.

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.

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.

Can You Replace Window Glass in Double Glazing Yourself?

With the right set of skills, removing a blown double-glazed unit in order to replace a uPVC window is relatively straightforward.

However, attempting the job yourself could void any existing warranties.

Poorly fitted windows may also affect performance and could impact your home insurance in the event of an emergency.

By hiring a professional, you not only ensure the job is done correctly, but you also avoid unnecessary stress and benefit from their guarantees.

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 glass, whether it’s toughened, and the type of glazing used. While ordering the glass yourself might save money, most installers will include the cost of the glass in their overall quote.

What’s the Process of Repairing a Window?

Replacing a double glazed unit is fairly straightforward. A local handyman or DIY enthusiast should be able to do it.

However, the difficult part and the part which can often lead to expensive mistakes is the initial measuring of the window before placing an order with a manufacturer.

Any mistakes in these initial measurements can result in a brand-new double glazed unit which simply will not fit properly into the existing window frame.

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.

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 replacement glass 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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