COST GUIDES
How much does double glazing cost in the UK in 2026?
Updated 05/26
Average cost:
Double glazing can cost anywhere from £500–£5,000+ per window
Average cost 3-bed house:
The average cost of double glazing for a 3-bed house is around £8,000–£15,000
Good to know:
It's always sensible to keep a contingency fund of around 10–15% to cover unexpected costs or slight changes
Compliance & regulations:
Always hire a tradesperson with experience and relevant qualifications and/or accreditations
Old or failing windows have a habit of creeping up on you slowly. Maybe the house feels colder than it used to. Perhaps there’s condensation trapped between the panes, draughts around the frames, or outside noise becoming harder to ignore. For some homeowners, replacing double glazing is about improving energy efficiency. For others, it’s simply about making the house feel warmer, quieter and more comfortable again. The cost of double glazing depends on:
The size of your property
The type of windows you choose
The frame material
How straightforward the installation is
This guide explains typical double glazing window costs in the UK, including average window replacement costs, what affects the final price, and what to expect when budgeting for new windows.
How much does double glazing cost in 2026?
While the average price for a standard uPVC casement double glazed window starts at around £500 per window, you'll pay more for different material frames or specialist security features.
| Type of window | Range - Low | Range - High | Average cost |
|---|---|---|---|
| Casement windows | £500 | £1,250 | £1,000 |
| Sash windows | £700 | £1,500 | £1,200 |
| Sliding windows | £600 | £1,400 | £1,100 |
| Tilt and turn windows | £600 | £1,400 | £1,100 |
| Bay windows | £1,100 | £4,000 | £2,500 |
| Bow windows | £1,500 | £5,000+ | £3,000 |
| Last updated: May 2026 Our costs are ballpark averages - get a local tradesperson to quote now | |||
As a rough guide, standard uPVC casement windows are usually the most affordable option, while larger bay, bow and sash windows tend to cost more because of the additional materials and installation time involved. Your final quote will also depend on the frame material, glazing upgrades, access requirements and the condition of your existing window openings.
Get a quote for double glazing costs near you
Double glazing quotes can vary quite a bit depending on the specification, installer rates and the complexity of the job. For a more accurate idea of costs, it’s worth asking a few checked local installers to assess your property and provide itemised quotes. Compare checked double glazing installers near you and compare quotes for your project.
Find checked double glazing installers working in your area
Double glazing costs at a glance
uPVC casement window: around £500–£1,250 per window
Sash window: around £700–£1,500 per window
Sliding window: around £600–£1,400 per window
Bay window: around £1,100–£4,000
Bow window: around £1,500–£5,000+
Average cost of replacing double glazing in a 3-bed house: around £8,000–£15,000
Double glazing installer hourly rate: around £25–£35 per hour
Double glazing installer day rate (two installers): around £600 a day
Scaffolding hire: around £1,000 a week
Average cost of new windows for a 3-bed house in the UK
For a typical 3-bedroom house in the UK, the average cost of new double glazed windows is around £8,000–£15,000. That’s usually based on replacing around 8–12 windows, although every property is different. Some homes may have larger bay windows, extra cloakroom windows, or more complex upstairs access requirements, all of which can affect the final cost. The type of window you choose will also make a noticeable difference. For example, sash windows and bay windows are usually more expensive than standard uPVC casement windows because they involve more materials and longer installation times. Frame material also affects pricing. uPVC is often the most budget-friendly option, while timber and steel windows tend to cost more. As a very rough guide:
Smaller 2-bedroom homes may cost less if fewer windows need replacing
Larger 4-bedroom homes often cost more because of additional windows, larger openings and longer installation times
Even homes with the same number of bedrooms can vary quite a bit in price depending on the number of windows, frame material, glazing upgrades and access needed.
Cost of double glazing by window type
The cost of double glazing windows can vary quite a bit depending on the style of window you choose.
Here are some of the most common types of windows, and their costs and benefits to help you weigh up the options:
1. Casement windows
Casement windows cost between £500 - £1,250 per double glazed window.
Casement windows are hinged on one side and open outwards, so they're great for ventilation. Other benefits of double glazed casement windows include their durability, security, and energy efficiency.
2. Sliding windows
Sliding windows cost between £600 - £1,400 per double glazed window.
Sliding windows are often chosen for wider openings because they’re easy to operate and don’t swing outward. Other benefits of sliding double glazed windows include their affordability, versatility, and low maintenance.
3. Sash windows
You'll want to budget roughly £700 - £1,500 per sash double glazed window.
This is one of the pricier double glazed options. That's because sash windows have more complex internal mechanisms, and installation takes longer.
Want prices for doors? Check out our guide to double glazing door costs.
Double glazing prices by window material
Once you've decided on the type of window you want, the next factor to weigh up is the material of the window frame. Here's a run-down of pros, cons and average cost for the most popular materials:
1. uPVC double glazed windows
uPVC windows are one of the most popular and wallet-friendly options for double glazing. Let's look at the costs, pros and cons:
Average cost: a uPVC casement window will cost between £500 to £1,250 per window
Pros of uPVC
Cost-effective – They can be up to three times cheaper than wooden frames
Energy efficiency – According to the Energy Saving Trust, if you installed A++ rated double glazed windows replacing single glazing, the savings could be up to £150 a year
Green grants available – Schemes like The Great British Insulation Scheme can potentially help towards your installation cost
Durability – They are also easy to keep clean
Variety – You can now get uPVC double glazing in a variety of colours and finishes, including a wood effect. Take a look at the different options in our uPVC window buying guide
Flexibility – If you have a bay window, uPVC windows can be designed to perfectly fit the sweeping design of your existing windows
Financial protection – Many uPVC installers offer guarantees and/or warranties
Cons of uPVC
Limited styles – May not fit with the look of some period homes
Saleability – Might not be seen as ‘desirable’ to some homebuyers
Environmental impact – Non-biodegradable material and limited recycling options mean they’re not the most eco-friendly option
Short lifespan – uPVC won’t last as long as wooden windows
Check out our buying guide for more information about uPVC windows.
2. Timber double glazed windows
Whilst not as energy efficient or cheap as uPVC, timber is, as you’d expect, the more environmentally friendly option when it comes to installing new double glazed windows on your home.
Average cost: around £925 for the supply and installation of a timber casement window (600x900mm)
Pros of timber
Eco-friendly – Wood is naturally renewable and timber windows don't require the chemicals and intensive processes that uPVC windows do
Desirability – Wooden windows are generally considered to look better, especially if your home is a period property
Flexibility – Timber windows are available in the same range of styles as uPVC
Durability – If well maintained and looked after, they can last a lifetime – making the initial investment worthwhile
Cons of timber
Higher initial investment – You can expect to pay at least 50% more for wood windows than for uPVC windows
Not as energy efficient – Compared to uPVC
Our timber window cost guide has loads more information to help you budget.
3. Aluminium double glazed windows
Average cost: the average UK cost of aluminium windows is £475
Pros of aluminium
Energy-efficiency – Although not a natural insulating material, modern aluminium doors often feature glazing that means they’re as good (if not better) than uPVC
Ultra-modern look – Slimmer, sleeker and lighter in profile
Durability and low-maintenance – Aluminium is a super strong and weather-resistant material (it’s used to build aeroplanes!)
Flexibility – Although typically supplied in its natural silver colour, aluminium double glazing can be painted in a number of shades
Financial protection – As with uPVC windows, many aluminium window installers offer guarantees and/or warranties
Cons of aluminium
Higher initial investment – More expensive than uPVC, however, the amazing durability and low maintenance often pays off in the long run
4. Steel double glazed windows
Average cost: average cost of steel window ranges from £1,200–£2,500 depending on the style
Pros of steel
Designer-look – These Crittall-style windows are a popular choice for homeowners looking for that minimal, industrial look in their homes
Flexibility – Although usually seen in black, steel windows are easily painted in all colours to suit the style of your property
Energy-efficient – Has excellent insulation qualities
Low-maintenance – Just need an occasional clean
Eco-friendly – Can be made from recycled materials
Cons of steel
Comes at a price – More expensive than other window types
Heavy – You may notice this when opening and closing your steel windows
Depending on the project, you may also need – or want – to carry out additional work, such as replacing your window sills or adding curved heads above your windows.
What affects the cost of double glazed windows?
Double glazing prices can vary quite a bit from one property to another. Two homes with the same number of bedrooms can still end up with very different quotes depending on the windows involved and the complexity of the installation.
The main factors that affect the cost include:
Property size and number of windows: Larger homes usually need more double glazing windows replaced, which naturally increases both material and labour costs
Window type: Simple casement windows are usually cheaper than bay, bow or sash windows, which are larger or more complex to install
Upstairs access: If installers need scaffolding or specialist access equipment to safely reach upper-floor windows, costs will rise
Frame material: uPVC is usually the most affordable option. Timber and steel frames are often significantly more expensive
Glazing upgrades: Optional upgrades such as triple glazing, laminated glass, frosted glass or Low-E coatings can all increase the overall cost
Acoustic double glazing: Specialist acoustic glazing designed to reduce outside noise is often more expensive than standard double glazing
Coloured frames and finishes: Anthracite grey, chartwell green and wood-effect finishes tend to cost more than standard white uPVC
Security features: Upgraded locks, laminated safety glass and additional security features can increase the price
Installation complexity: Older properties, awkward openings, damaged brickwork or difficult access can all add labour time
Your location: Double glazing installer rates typically fall between £25–£35 per hour, or around £600 a day (for two installers). However, rates are often higher in London and the South East
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Additional costs to budget for
The window cost itself is only part of the overall project budget. Depending on your property and the specification you choose, you may also need to budget for:
Scaffolding or access equipment
Plaster repairs around the window openings
Internal redecorating after installation
Disposal of old windows and materials
Upgraded locks or security features
Acoustic or specialist glazing upgrades
Trickle vents
Replacement window boards or sills
Making good internally around the frames
If you’re replacing older windows, there can sometimes be hidden repair work underneath once the old frames are removed. It’s sensible to keep a small contingency budget aside for unexpected issues.
Glass upgrades and optional extras
There are also different types of glass to choose from, which can hike up double glazed windows prices.
Upgrades include:
Low-emissivity (Low-E) coating: Reflects heat back into the room and helps reduce energy bills
Laminated glass: For enhanced safety and security
Triple glazing: Adds an extra pane of glass for even better insulation and noise reduction
Additional PVB layers: Help improve safety, security and noise reduction
Frosted glass: Etched or sandblasted to provide privacy and light diffusion
Self-cleaning glass: Has a special coating that breaks down dirt and grime, making it easier to clean
Acoustic double glazing: Uses specialist glass designed to reduce outside noise from roads, neighbours or busy areas
Acoustic double glazing costs more than standard double glazing because it uses specialist glass designed to reduce outside noise. It’s commonly chosen for homes near busy roads, schools or flight paths.
What’s usually included in a double glazing quote?
A clear quote should explain exactly what’s included in the installation cost, and what isn’t. Most double glazing quotes will normally include:
Removal of existing windows
Supply and installation of the new windows
Standard glazing and window furniture
Labour costs
Basic making good around the frames
Waste removal and disposal
VAT (if applicable)
Some quotes may also include:
FENSA certification
Guarantees or warranties
Trickle vents
Window restrictors or upgraded locks
However, it’s always worth checking whether the quote excludes things like scaffolding, plaster repairs, decorating, or upgraded glazing options.
If you’re comparing quotes, check that the specification is genuinely like-for-like. Cheaper quotes sometimes use lower-spec glazing, fewer opening windows, or exclude finishing work.
How long does double glazing installation take?
The time needed to install double glazing depends on the size of your property, the number of windows being replaced, and how straightforward the access is. As a rough guide:
Replacing a single window may take a few hours
A typical 3-bed house often takes around 2–4 days
Larger homes or more complex installations can take longer
Most installers will work through your property room by room, removing the old windows before fitting the new units and sealing everything into place. It’s worth being prepared for a bit of disruption while the work is happening:
Replacing windows can be noisy and dusty at times, especially when older frames are being removed
Furniture may need moving away from the windows
You may also find access around parts of the house feels a bit restricted while the installers move from room to room
Weather can sometimes affect installation schedules too, particularly during very wet or windy conditions.
Questions to ask before hiring a double glazing installer
Before agreeing to any work, it’s worth asking a few practical questions so you know exactly what you’re paying for, and who’s carrying out the installation.
Most reputable window installers will be registered with a recognised Competent Person Scheme, such as FENSA or CERTASS. This helps show the work meets current building regulations. You can also ask for their ID number to check their credentials.
Accidents are rare, but it’s important your installer has up-to-date insurance in place in case any damage happens during the work.
Reviews can help you understand how the installer communicates, handles problems and manages the installation process from start to finish.
Check whether guarantees cover both the windows themselves and the installation work.
Some quotes exclude things like plaster repairs, decorating or disposal of old windows, so it’s worth checking upfront.
Double glazing cost calculator UK
Use our calculator below to get a rough idea of what your double glazing project could cost.
Choose your windows
Item | Avg Unit Cost | Your Cost |
|---|---|---|
Casement windows | £1,000.00 each | |
Sash windows | £1,200.00 each | |
Sliding windows | £1,100.00 each | |
Tilt and turn windows | £1,100.00 each | |
Bay windows | £2,500.00 each | |
Bow windows | £3,000.00 each |
Add items (specify quantity of each)
Item | Avg Unit Cost | Your Cost |
|---|---|---|
Labour (Two installers) | £0.00 per day |
Estimated overall cost:
£0.00
Working with professional estimators, we collate cost estimates for the common home improvement and repair jobs in the UK. All the costs are estimates only and for accurate costs for your particular requirements, you are encouraged to reach out to professional tradespeople to receive a quote for your job. Read our disclaimer for more information.
This calculator provides a guide price only, not a quote. For an accurate cost, ask several checked installers to assess your property and provide an itemised written quote.
Alternatively, here's a quick way to calculate the cost of your new double glazing:
Cost of windows + Labour cost + Additional costs* = Total double glazing cost
*Additional costs might include scaffolding, specific non-standard locks, upgraded glass, and special window treatments.
It's also a good idea to keep a contingency fund of around 10–15% to cover unexpected costs or slight changes to the spec of your double glazed windows.
Find checked double glazing installers working in your area
Can you install double glazing yourself?
Some confident DIYers may consider fitting their own windows to save money, particularly when replacing smaller ground-floor windows. However, double glazing installation is usually best left to an experienced installer. Windows need to be fitted level, properly sealed and compliant with current building regulations. Poor installation can lead to draughts, leaks, condensation problems, heat loss and security issues later on. There’s also the practical side to think about. Double glazed units are heavy, awkward to manoeuvre and easy to damage if handled incorrectly, especially upstairs or around larger openings, such as bay windows. For most homeowners, the reassurance of having the installation professionally fitted, certified and guaranteed is usually worth it.
How to save money on double glazing installation
If the costs are adding up more than you hoped, before scrapping the idea completely, here are some tips to help reduce the costs:
Stick to standard size windows and frame colour: The more bespoke the windows, the higher the cost
Green grants: There could be government incentives to help cover the costs
Look into finance options: Some of the larger double-glazing companies offer financing or payment plans to help spread the cost
Consider professional repairs instead: Fixing your existing double glazed windows is another option if you can't afford to fork out on new ones just yet. Our double glazing repairs planning guide runs through what's doable
Shop around for multiple quotes: Compare quotes from several tradespeople to help understand what a fair price looks like
Double glazing cost checklist
When should you consider replacing double glazing?
Many homeowners live with older windows for years before deciding whether replacement is actually worth it. In some cases, a repair may be enough. But there are certain signs that your double glazing may no longer be performing properly. You may want to consider replacement if:
Your windows feel draughty even when closed
Condensation appears between the panes of glass
Rooms feel colder than they used to
Outside noise seems much more noticeable
Window frames are rotting, warped or damaged
Windows are difficult to open or close
Heating bills are creeping up
Your windows no longer feel secure
Your home still has older single glazing
Older double glazing windows can gradually become less energy efficient over time, particularly if seals begin to fail.
Even small issues can sometimes point to larger problems developing behind the frames. Catching problems earlier is often less disruptive than waiting until windows fail completely.
Find a double glazing installer near you
Replacing windows is a significant investment, so it’s worth taking time to compare quotes and understand exactly what’s included. A good installer should assess your property properly, explain your options clearly, and help you understand any practical issues that could affect the final cost.
Search your postcode to see the double glazing installers working in your area and request quotes for your project.
Browse checked installers offering double glazing windows in your area
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FAQs
To get a rough idea of how much you should pay for double glazing, start with a ballpark figure of between £500 to £1,250. This cost is for a no-bells-and-whistles white uPVC casement window. This figure will climb when you start looking at wooden or coloured uPVC windows.
Professionally installed and well-maintained, double glazed sealed windows last between 10 to 20 years on average. So, if your current double glazing is pushing on twenty years, it’s definitely worth looking into replacing them. It will help retain your home’s vital heat in the colder months and save on your heating bills.
The Energy Company Obligation (ECO) scheme is a good place to start if you'd like to look into green grants available for double glazing. It requires medium and large energy suppliers (‘obligated’ suppliers) to help eligible households cut their heating costs by fitting energy-saving measures like window glazing improvements. Our green grants expert advice article has all the details.
If you live in a conservation area, you may need planning permission before changing your windows. A double glazing installer will be able to advise on this.
Absolutely, double-glazing can add value to your home. Installing double-glazing is a no-brainer if you want to retain heat and make your home more energy-efficient. If you live in a busy city, double glazing window installation also has excellent sound insulation qualities.
The average cost of new double glazed windows in a typical 3-bed house is around £8,000–£15,000. That’s usually based on replacing around 8–12 windows.
It depends on the condition of the windows and how well they’re performing. Many double glazed windows can last longer than 10 years if they’ve been properly installed and maintained. However, if you’re noticing draughts, condensation between the panes, difficulty opening the windows, rising heating bills or increased outside noise, replacement may be worth considering.
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