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Window Glass Replacement Cost

By Sam

Last updated 18th June 2025 - Reading time: 12 mins

At a Glance

The average cost of replacing blown windows is around £70.
Double glazing glass replacement typically takes 1 hour.

In this guide, you'll find:

A breakdown of how much misted window repair costs for different-sized units.
An overview of what the job involves and expert advice from tradespeople on MyJobQuote.
How to find and hire a local window specialist.

Struggling with misted or blown double glazing? Need to know how much window glass replacement costs in 2025?

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. The exact price you're quoted will mainly depend on the size of the window.

This guide includes everything you need to know about window glass replacement prices in the UK. From repairing uPVC windows and fixing misted panes to replacing blown double glazing, this guide has you covered.

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window glass replacement cost guide — person replacing a window

Average Window Glass Replacement Cost:

Depending on the complexity of the job, it usually takes: 30 – 60 minutes

£70

How Much to Replace Double Glazing Glass?
- Window Glass Replacement Prices
How Long Does Window Glass Replacement Take?
Things to Consider with Blown Double Glazed Units
What Affects the Cost of Replacement Double Glazed Units?
What Extra Costs Are Connected With Blown Windows?
Can You Replace Window Glass in Double Glazing Yourself?
Blown Double Glazing Checklist
FAQs
Sources

How Much to Replace Double Glazing Glass?

Let's get started...

Replacing blown double glazed windows can often seem like an expense you could well do without.

However...

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.

If you want brand new double glazing for all your windows, then read our new double glazing cost guide.

Can you repair a blown window yourself?

You can do this yourself as a DIY project. But if you do, you'll have to be very precise with the measuring. Most people will simply get a local joiner or window fitter to do the job.

Would you rather a professional do it? How do you find one?

A great way to find a reliable local window fitter is through recommendations from friends, family or neighbours.

But if this is not possible, then we provide a free and easy-to-use service on MyJobQuote. You can simply enter brief details about the job, and then you can have up to 3 local tradespeople get in touch with you to provide written quotations.

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."

Hampshire Windows Doors

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.

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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How Long Does Window Glass Replacement Take?

The table below provides an estimate of how long it typically takes a specialist to make double glazing repairs like this.

In short? It should not take an experienced tradesperson more than about an hour to correctly replace the glass in a double glazed window.

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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Things to Consider with Blown Double Glazed Units

How do glazed windows become blown?

There are some key causes of blown windows:

Failed seal.
Older windows that have failed over time.
Weakened glass.
Accidental damage.
Poor window installation.

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

How long do you expect double glazing to last before problems occur?

5 years or less

25 votes - 11%11% of votes

6 – 10 years

44 votes - 19%19% of votes

11 – 15 years

54 votes - 23%23% of votes

16 – 20 years

45 votes - 19%19% of votes

More than 20 years

63 votes - 27%27% of votes

231 votes See results

What's the process of repairing it?

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.

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.

Six Home improvements

Is replacing a glazed unit complicated?

Replacing a double glazed unit is fairly straightforward and in fact, any 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.

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.

Here are some examples:

Number of Panes

If there is only one pane with misty windows then 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 to ensure they're paid fairly for their work.

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 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. Yet triple glazing is also becoming popular and 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, with the cost of this glazing style generally higher.

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's.

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 resolving 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?

Removing blown double glazed units and replacing a double glazed window is normally quite straightforward. However, some modern double glazed windows are fitted with special anti-theft blocks which can complicate things.

The double glazed units themselves can be held in place using pressure gaskets or double-sided tape — but in either case, can be removed relatively easily.

Before ordering the replacement double glazed unit you will not only have to be very precise with the measurements, but you will also need to know the thickness of the glass panes, whether the glass is toughened, and the type of glass. For example, is the glass tinted or standard?

With the right skills and tools, DIY replacement of a double glazed unit is certainly possible.

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."

Revive Windows & Doors

But you also have to consider that this is not a terribly expensive job and if you get a professional in then the job won't take as long, or be as messy, and will be much less hassle and frustration, and you can avoid a potentially shoddy job being done and then having to hire a professional in anyway!

Blown Double Glazing Checklist

Blown double glazing is much less energy-efficient so will cost you money
With blown double glazing you do not have to replace the entire window
Misted-up double glazing units can also be repaired in some cases
Replacing a double glazing unit is fairly straightforward

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FAQs

How much does it cost to replace a blown double glazed window?

Normally, this would simply involve replacing the double glazed unit itself rather than the entire window. So this, in most cases, will be a relatively cheap job, with the bulk of the costs actually being the labour.

How much does replacement sealed double glazing unit cost supply only?

You can buy double glazed units in standard sizes from as little as around £20.

How long should my windows last before they start misting up?

This really depends on the quality of the windows. Many customers report no problems with double glazing after 15 years or more. On the other hand, there are instances of blown double glazing happening within five years of installation.

What causes condensation between the panes of a double glazed window?

In most cases, this is caused by the seal around the window feeling and allowing moisture to get in between the panes. However, there can be other reasons which mainly relate to any building work going on in the immediate vicinity of the window.

Is replacement the only option with blown double glazing?

No, you can also have double glazed windows repaired in some situations by specialist companies. However, this is not always possible and depends on the type of glass used in the window frame.

Is resealing a good blown double glazing repair?

It's usually recommended that you opt for a replacement unit rather than resealing a blown window. This is because 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.