How much do replacement windows cost? (2023 guide)

Considering replacement windows? Our guide examines the costs for different types and styles, benefits, and when you should get replacement windows.

By Architectural Digest UK Reviews Team

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Jump to: Benefits of replacement windows | When to replace windows | How to choose windows | Replacement window styles | Standard window sizes | How to measure your windows | Installation process | Life span of windows | Types of glass | Costs | Double glazing vs triple glazing | Quote process | Our methodology | FAQ

Double glazing windows are a good energy-efficient investment for your home, especially with the cost of living crisis looming. But what is the cost of replacement windows should you need them? 

While double glazing windows have an average life span of around 20 to 35 years, you will likely need to consider the cost of replacement windows at some point. In fact, some double glazing windows begin to lose their energy efficiency long before their average life span is up.

The total cost for your replacement windows depends on the amount of windows required, the frame type, and the window style you choose. The most common frame material chosen by UK homeowners is uPVC. It is a durable frame with relatively low maintenance, and it is very cost-effective. 

The below table outlines the average cost for uPVC casement replacement windows according to property size.

House typeAmount of windowsCost of windowsInstallation

Flat

4–5

£1,240–£2,480

£190–£370

Terrace

6–10

£1,860–£4,960

£190–£370

Semi-detached

11–15

£3,410–£7,440

£190–£370

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Benefits of replacement windows

Replacing old windows with new ones—particularly double or triple glazing—can provide a number of benefits that make the initial cost well worth it, including:

When should I get replacement windows?

Replacement windows have many benefits:

There are a myriad of reasons why you might consider replacement windows. If you currently have single-glazed windows, then upgrading to double glazing is a worthwhile investment, especially if you are looking to cut your energy bills. Single glazing loses heat twice as fast as double glazing, and just by installing double-glazed windows you could save up to £235 per year, according to Energy Saving Trust

As well as cutting your energy bills, replacement windows could add value to your home. This means the amount you can sell your house for might increase due to the wealth of benefits that new double glazing windows bring, like added security, noise reduction, and higher energy efficiency. 

You should also consider replacements if your existing windows look noticeably decayed or cracked in any way. This could mean they have lost some of their insulation benefits and therefore are not working to keep your home energy efficient. Double glazing windows need to be maintained and kept free of dust and dirt; if they are not, you could end up with condensation on the inside pane of your windows, which may lead to needing to replace them.

How to choose your replacement windows

With lots of styles and material options on the market, choosing your double glazing windows can be tricky. Windows come in varying styles, and you can even opt for different colours and finishes. You should consider that windows have a long life span, so this is not a decision to rush into.

Take your time considering which frame style suits your home and the benefits that they can bring. Considering the average home has around 10 windows, they can completely change the appearance of your home. With that being said, it is becoming ever popular to opt for coloured windows for a unique look. 

One popular window choice is uPVC for many different reasons, but more recently it’s due to how easy it is to customise them. You can buy uPVC windows in more stylish colours than just plain white, and many manufacturers also offer wood-effect finishes. 

However, whilst different coloured windows may look stylish, you should consider how this could affect your house in the long run. It might be worth sticking with windows that appeal to the widest market if you are considering selling your home in the near future.

Replacement window styles

There are several different styles of window, with each offering its own benefits and aesthetic appeal. Here is a general breakdown of the types of windows available on the market today:

What are standard UK replacement window sizes?

Windows come in a variety of sizes, frames, and styles, and most manufacturers do offer a standard size. It is important that you know the correct size of windows you will need in order for your installer to manufacture them. In most cases, standard window sizes will suit your home, but bespoke windows can also be manufactured where necessary.  

The below table shows the standard UK window sizes according to Everest.

Window typeHeight (in millimetres)Width (in millimetres)

uPVC

1500, 1350, 1200, 1050, 600, 450

1770, 1200, 915, 630, 488

Casement

635 x 890, 736 x 1194, 736 x 1498

Sash

609, 914, 1219, 1524

914, 1219, 1524, 1829, 2134

Bay

914.4 – 9181.2

1016 – 3200

How to measure your windows

A woman measuring for replacement windows.
Measuring for replacement windows is usually done by a surveyor sent by your installer, but you can do it yourself to get an idea of costs. (Image credit: Adobe)

Measuring for replacement windows can be a simple task if you know how to measure them effectively. However, if you do not get the measurements right, then this could cause problems.

The best thing to do would be to have your installer measure your windows to ensure there are no discrepancies. Most installers will do this as part of your property survey before they start making your windows. But if you need to measure for replacement windows yourself, or you want to get an idea of how much your project will cost before you start gathering quotes, then this is how you do it. 

Measure your window from the outside

Make sure you hold the tape measure straight

Measure the height of the window

Measure the width

 Check if the window has sagged

10 millimeter deduction rule

Measure more than once

What is the installation process for replacement windows?

When it comes to installing replacement windows, the time it takes to do this can vary. Usually, it largely depends on how many windows you’re having installed. The average UK house has 10 windows, and a flat has between four and five. Most of the time installation can be completed in one day. However, if you have a larger property that has more windows, the installation time may take slightly longer. 

The below table outlines the average cost and installation time according to the number of replacement windows that you need.

Number of windowsCost (excluding installation)Installation time

4–5

£1,000–£1,250

1 day

6–10

£1,500–£2,500

1 day

10+

£2,500+

1 day+

When it comes to ordering replacement windows, it is useful to know what to expect from your installer. This step-by-step guide should help you better understand the process.

  1. Get a quote from a windows installer that services your local area and is FENSA approved. Shop around and get more than one quote to compare costs and lead times. Arrange visits from more than one windows provider too.
  2. Your chosen providers will visit your home. They will assess your requirements and discuss styles, materials, and colours with you.
  3. Once you receive your quotes from all of the providers that assessed your home, you should now decide which one suits you best. Consider the total cost and warranties that the companies offer. Once decided, you will likely be asked to pay a deposit to proceed.
  4. Decide dates for installation. At this stage, your installer will confirm dates with you and estimate how long the process should take.
  5. Make your final payment. Once the installation is complete and you are happy with the work done, you will make your final payment. You should also receive your FENSA certificate.   

Double glazing windows life span

Replacement windows cost. A large timber-framed window in a stylish living room with wooden floors and exposed wooden beams.
Timber replacement windows tend to have the longest life span but require the most maintenance. (Image credit: Adobe)

Although most companies will give you a standard warranty with your replacement windows, that doesn’t mean that all windows last the same amount of time. On average, new windows will last between 20 and 35 years. However, the type of frame you opt for largely dictates just how long your windows will last.

The below table outlines the average life span for each window frame to help you make an informed decision.

Frame typeLife spanMaintenance

uPVC

20 years

Low maintenance

Aluminium

25 years

Medium maintenance

Timber

50+ years

High maintenance

Composite

50+ years

Medium maintenance

Types of glass

Low Emissivity (Low-E) glass

Low Emissivity glass—more commonly known as Low-E—is the most energy-efficient type of glass available in the UK. It has an invisible, microscopic coating that improves double glazing’s thermal efficiency by boosting something called thermal gain. With thermal gain, short wavelength heat from sunlight is allowed to pass through the glass. Once inside your home, the heat is transferred to long wavelength energy, which works with your central heating to warm your home. These longer wavelengths are reflected back into your home by the glass’s coating, preventing the heat from escaping. Coupled with the insulating properties of double glazing windows, Low-E glass can help maintain more heat inside your home, particularly in colder areas.

Acoustic glass

Acoustic glass is designed to dampen sound waves and thereby reduce the amount of noise being transferred through the glass—both from the outside to the inside and vice versa. It consists of two panes of glass bonded together by a layer of polyvinyl butyral resin (PVB), which provides the sound dampening properties of acoustic glass. While double glazing windows already provide some noise reduction, acoustic glass takes this one step further, making it the ideal option for homes near busy roads or other noisy areas.

Security glass

Sometimes referred to as laminated or safety glass, security glass usually ranges in thickness from 7.9 millimetres to 18 millimetres and is laminated with a coating of PVB. This allows the glass to withstand high impacts from objects such as crowbars. Even if the glass breaks, the lamination prevents it from shattering, making it a good choice for areas where safety is key, such as homes with small children.

Solar control glass

Whereas Low-E glass is designed to allow buildings to use the sun’s rays for extra heat, solar control glass has the opposite effect. Perfect for use in hot, sunny climates, this type of glass uses invisible layers of material to allow light from the sun to pass through while reflecting much of the heat energy away.

Self-cleaning glass

Cleaning your windows is important for keeping them in tip-top shape, but the time and effort is a hassle for some people. Self-cleaning glass uses a transparent coating that breaks down dirt as it settles, allowing it to be easily washed away by rain. The coating typically needs a few days’ worth of UV rays from the sun to activate after being installed.

Decorative glass

Many double glazing windows installers offer a range of decorative glass, which includes different colours, frosting, and even etching to make your windows stand out. Some companies can even combine decorative glass with some of the other types of coating to provide numerous benefits for your home.

What is the cost for replacement windows?

When it comes to the cost of replacement windows, there are a number of factors that affect that cost. The cost for replacement windows depends on the type of frame material, the style of the window and its size. 

It is no easy feat finding out the cost of replacement windows since most installers would need to visit your home in order to provide you with a specific quote. We have outlined the average costs per window using frame styles and sizes. The below table breaks down the typical price of casement windows.

Window frame material600 mm x 900 mm900 mm x 1200 mm1200 mm x 1200 mm

uPVC

£310–£500

£500–£750

£810–£1,120

Aluminium

£690–£870

£810–£1,000

£940–£1,250

Timber

£1,060–£1,250

£1,490–£1,740

£1,680–£1,870

Composite

£1,490–£2,610

£2,240–£3,480

£3,230–£3,980

Cost of uPVC window frames

The most common type of double glazing windows in the UK, uPVC window frames are highly durable and were designed to insulate homes and reduce noise. With the right maintenance, they could last longer than other frame types. However, this isn’t to say uPVC windows come without disadvantages, as they have a tendency to sag over time due to their lightweight material.  

As well as their attractive benefits, uPVC windows are relatively low cost—in fact, they are the most affordable frame type. The below table outlines the average costs for uPVC casement windows excluding installation.

Size of window (mm)Price per window—ground floorPrice per window—second floor

600 x 900

£310–£440

£380–£500

900 x 1200

£500–£560

£560–£750

1200 x 1200

£810–£940

£1,000–£1,120

Cost of aluminium window frames

Though more expensive than uPVC, aluminium frames are highly durable and lightweight, meaning they would add extra security and reduce noise. These types of frames are stylish and aesthetically pleasing, so they would be a good choice if you are looking to improve the look of your home. However, aluminium frames are poor insulators and don’t hold heat in as well as other materials, and as such they usually have a lower energy efficiency rating than uPVC. 

The below table outlines the average costs for aluminium casement windows excluding installation.

Size of window (mm)Price per window—ground floorPrice per window—second floor

600 x 900

£690–£750

£750–£870

900 x 1200

£810–£940

£870–£1,000

1200 x 1200

£940–£1,060

£1,120–£1,250

Cost of timber window frames

Timber frames are the most costly frame type. With that being said, they can add value to your home and are the most stylish frame choice. This type of frame has a life span of 50 years or more if they are well maintained.

Best known for its natural insulation, timber frames are especially good at keeping the heat in and out of your home. Timber frames are available in a number of finishes, and you can choose from hardwood or softwood. 

Timber frames do, however, require a lot of maintenance to prevent warping and rotting over time, such as regular painting or staining.

The below table outlines the average costs for timber casement windows excluding installation.

Size of window (mm)Price per window—ground floorPrice per window—second floor

600 x 900

£1,060–£1,180

£1,120–£1,250

900 x 1200

£1,490–£1,620

£1,620–£1,740

1200 x 1200

£1,680–£1,800

£1,740–£1,870

Cost of composite window frames

Composite frames are also costly like timber frames. That’s due to composite windows being a mixture of an aluminium frame cladded with timber. They require less maintenance but still have the elegant look of a timber frame. However, remember that aluminium frames do not hold the heat well, so the same would apply to composite frames. 

The below table outlines the average costs for composite casement windows excluding installation.

Size of window (mm)Price per window—ground floorPrice per window—second floor

600 x 900

£1,490–£2,240

£2,240–£2,610

900 x 1200

£2,240–£3,230

£3,230–£3,480

1200 x 1200

£3,230–£3,730

£3,600–£3,980

What is the cost for different window styles?

A large bay window made up of multiple white uPVC replacement windows.
Bay replacement windows tend to be more expensive since they include multiple sections. (Image credit: Adobe)

Another factor that affects the cost of replacement windows is your choice of window style. The below tables examine the cost of different window styles. 

Casement window prices

The most common window style in the UK, casement windows can be fixed or opened from the top, bottom, or from either side. Casement windows also come in varying sizes, which is probably why they are a popular choice.

Size of window (mm)StylePrice per window (uPVC—not including installation)

500 x 500

Fixed

£190–£250

1000 x 1000

Fixed

£250–£310

1200 x 1200

Fixed

£310–£380

500 x 500

One Opener

£310–£380

1000 x 1000

One Opener

£350–£410

1200 x 1200

One Opener

£440–£500

500 x 500

French

£560–£630

1000 x 1000

French

£630–£690

1200 x 1200

French

£660–£720

Sash window prices

Most commonly found on Georgian and Victorian buildings that are sometimes Grade II-listed, sash windows are typically fitted with timber frames and open horizontally—though they can be made with uPVC or aluminium as well.

Size of window (mm)Price per window (not including installation)

500 x 500

£690–£780

1000 x 1000

£810–£900

1200 x 1200

£940–£1,060

Tilt and turn window prices

This style of window has many advantages: Since the window opens inward, it’s a great option for a home with small children, and they are easier to clean and maintain.

Size of window (millimetre)Price per window (not including installation)

800 x 800

£560–£620

1000 x 1000

£620–£680

1200 x 1200

£680–£750

Bay window prices

Bay windows function both practically and as a stylish feature in your home. They also come in different designs such as oriel, bow, box, and circle bay windows.

Size of window (mm)Number of sectionsPrice per window (not including installation)

2400 x 1200

Three

£1,250–£1,490

3000 x 1200

Three

£1,490–£1,620

3000 x 1500

Three

£1,620–£1,740

3000 x 1200

Four

£1,870–£1,990

3600 x 1200

Four

£1,990–£2,110

3600 x 1500

Four

£2,110–£2,240

3600 x 1200

Five

£2,360–£2,730

4000 x 1200

Five

£2,490–£2,860

4000 x 1500

Five

£2,610–£2,980

Bow window prices

Bow windows introduce more light into your home, as they are curved, which can be seen from the outside. As well as being functional, they are also an aesthetically pleasing design element.

Size of window (mm)Number of sectionsPrice per window (not including installation)

2400 x 1200

Three

£1,250–£1,490

3000 x 1200

Three

£1,490–£1,620

3000 x 1500

Three

£1,620–£1,740

3000 x 1200

Four

£1,870–£1,990

3600 x 1200

Four

£1,990–£2,110

3600 x 1500

Four

£2,110–£2,440

3600 x 1200

Five

£2,360–£2,610

4000 x 1200

Five

£2,490–£2,730

4000 x 1500

Five

£2,610–£2,860

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Double glazing vs. triple glazing

Replacement windows cost. A cross-section of different windows showing the difference between double glazing windows and triple glazing.
This cross-section shows the difference between triple and double glazing replacement windows. (Image credit: Adobe)

Since the cost of living crisis has begun to affect many households across the UK, homeowners are considering the benefits of triple glazing.

Triple glazing benefits

With all of that being said, the energy efficiency benefits are not too dissimilar to that of double glazing. One of the main things to consider with triple glazing is the cost. Triple glazing is more expensive than double glazing since it has an extra air gap with a third pane of glass. However, it is worth noting that by some estimates, replacing single glazing or old double glazing with triple glazing can save you £766 per year on your energy bills, while upgrading from single to double glazing can save between £195 and £235 annually. 

To give you a ballpark figure, a uPVC double-glazed window is upwards of £100 and a uPVC triple-glazed window is upwards of £500.

What is the process for a replacement windows quote?

Getting a quote for replacement windows can be tricky if you are not sure what to expect or the right questions to ask. It’s also important to get windows quotes from more than one provider so that you can compare prices and other features like warranty and installation costs.

These are some of the main things to consider when receiving a windows quote:

This is what the total quote from any windows installer should include:

How we determined these prices

We based the cost figures in this article on market data from August 2021. We have applied an average 24.1% increase to the data based on UK Government analysis of the construction sector for August 2022, which found there was a 24.1% increase in the cost of building materials and services compared to the same month the previous year.

Replacement windows FAQ

What type of window frame is the most affordable?

uPVC windows are the most common type of window style installed in the UK. This could be due to its relatively low cost compared to other styles.

What type of window style has the lowest price?

Typically, the most cost-efficient window style is casement. It’s a very versatile type of window and can be installed to open in different ways.

How long do double glazing windows last?

Double glazing windows typically have a life span of between 20 and 30 years. However, they can last longer than this with the right maintenance.

Is it less expensive to replace all windows at once?

Yes, it is most cost-effective to replace all of your windows at once. This is because you will only have to pay for one installation cost if the entire house is done at the same time. Whereas if you need more than one installation day, this will obviously be twice the cost or more.

How many days does it take to replace windows?

Typically it takes only one day to replace windows. With that being said, this depends on your house size. For the average house, one day is more than enough but for a larger property, it may spread over more than one day.

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