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The cost of replacement windows for a semi-detached three-bedroom house in the UK is typically around £4,000. However, replacement double glazed windows prices are affected by factors such as the frame material and window style. Despite the cost, it’s a worthwhile investment, as double glazing can save you up to £260 on your annual heating bill, which is a reduction of 20 per cent. Opting for triple glazing can lead to even greater savings, although the upfront costs are typically higher compared to double glazed windows.
In our guide we look at installation costs and explain how the price depends on the various designs, materials and styles of replacement windows. We also offer advice about how you can tell when it’s time to replace your windows, and we include tips on how to ensure you get the most competitive quotes and how to accurately measure your home for new windows.
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To provide an idea of current replacement window prices, we’ve listed average costs for double glazing a three-bedroom home with eight windows in various styles and frame materials. We recommend getting multiple quotes, as costs will vary based on window size and installer.
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| Window type | Material | Average cost per window | Average cost for a three-bedroom house |
|---|---|---|---|
| Casement | uPVC | £525 | £4,200 |
| Casement | Aluminium | £1,054 | £8,400 |
| Casement | Timber | £1,581 | £12,600 |
| Sash | uPVC | £1,100 | £8,800 |
| Sash | Timber | £3,300 | £26,000 |
| Bow/Bay | uPVC | £1,700 | £13,000 |
| Bow/Bay | Aluminium | £3,400 | £27,200 |
| Bow/Bay | Timber | £5,100 | £40,500 |
Our experts spent hundreds of hours researching the best options to help you make an informed decision about purchasing new windows We examined the performance and features of each type of window, compared costs and analysed customer feedback. Here’s a full breakdown of how we cover windows.
When it comes to replacement windows costs, uPVC is the cheapest frame material available.
In addition to being affordable, uPVC windows are durable, and require minimal upkeep. This makes them a popular choice for anyone looking for an alternative to more traditional timber and aluminium frames.
| Casement window frame material | 600mm x 900mm | 900mm x 1,200mm | 1,200mm x 1,200mm |
|---|---|---|---|
| uPVC | £527 | £597 | £650 |
Double glazed uPVC windows have excellent insulation properties, so they can minimise energy loss, leading to lower electricity bills and a warmer house. They also significantly improve sound insulation by reducing external noise, creating a quieter indoor environment. Many double glazed units incorporate multiple point locks which increase your home’s security measures.
If you’re keen to personalise the exterior of your home, many manufacturers offer a variety of coloured uPVC windows, or if you prefer the appearance of timber frames without the cost, some companies offer uPVC with a wood-effect finish.
| Casement window frame material | 600mm x 900mm | 900mm x 1,200mm | 1,200mm x 1,200mm |
|---|---|---|---|
| Aluminium | £1,054 | £1,194 | £1,300 |
Despite aluminium windows not being as popular as uPVC, their slimmer frames and large panes typically allow more natural light into your home. Aluminium is stronger than uPVC, but during winter, the frames are colder to the touch, and the glass is more prone to condensation, as aluminium doesn’t have the same thermal efficiency as uPVC.
As with uPVC, you only need to occasionally wash aluminium windows to keep them in good condition, so they are easy to maintain. Aluminium frames are available in a wide range of colours, allowing you to customise their appearance to match any aesthetic. However, aluminium double glazing typically costs twice as much as uPVC.
| Casement window frame material | 600mm x 900mm | 900mm x 1,200mm | 1,200mm x 1,200mm |
|---|---|---|---|
| Timber | £1,581 | £1,791 | £1,950 |
Timber is an excellent choice if you want both the efficiency of double glazing and the traditional look of wooden window frames. Although timber frames are around triple the price of uPVC windows, they can significantly increase your property’s value.
If you keep your timber frames weatherproof by occasionally refinishing and repainting them, they can last for many years. So, if you live in a period property, or you just like the look and feel of natural materials, then timber is an ideal choice.
Prioritise draughty windows to reduce installation costs.
You can reduce the cost of materials and labour by installing a complete set of new windows, which is a more cost-effective option in the long run. However, if you want to keep costs down, you could choose to only upgrade the front-facing or most problematic windows – such as those that are single glazed, leaky or damaged.
Double glazing can save you between £235 and £260 on energy bills each year, and the biggest savings occur over winter.
Although it can take a few years to break even, you should see immediate improvements in your home’s draught-proofing and insulation, saving you money on your energy bills.
While bay and bow windows are the most expensive options – as they are more complex to manufacture and install – most budget-friendly option.
| Casement window frame material | 600mm x 900mm | 900mm x 1,200mm | 1,200mm x 1,200mm |
|---|---|---|---|
| uPVC | £527 | £597 | £650 |
| Aluminium | £1,054 | £1,194 | £1,300 |
| Timber | £1,581 | £1,791 | £1,950 |
Casement windows in uPVC are the least expensive option, with prices ranging from £527 to £650 per window. These windows are also available with aluminium or timber frames, with the latter being the costliest. Usually, casement windows have side-hinged panes that open outwards like a door, but you can also have hinges at the top or bottom. The bottom-hinged designs are the safer option if you have young children.
| Sash window frame material | 600mm x 900mm | 900mm x 1,200mm |
|---|---|---|
| uPVC | £1,100 | £1,180 |
| Timber | £3,300 | £3,200 |
Sash windows, popular in period properties, are often installed in new builds to mimic traditional architecture. Prices tend to range from £1,100 to £3,200 per window, with the cost of uPVC sash windows being the lowest.
Combining a classic style with modern double glazing technology, sash windows consist of one or more movable panels that open and close by sliding vertically (or occasionally horizontally). They typically incorporate lockable handles, instead of the bar handles seen on traditional sash windows.
As few manufacturers make sash windows with aluminium frames, your choice is usually limited to uPVC or timber. Timber frames cost more upfront, but they can last much longer than uPVC if you maintain them properly.
| Tilt and turn window frame material | 600mm x 900mm | 900mm x 1,200mm | 1,400mm x 1,400mm |
|---|---|---|---|
| uPVC | £500 | £570 | £655 |
| Aluminium | £720 | £850 | £1,020 |
| Timber | £1,000 | £1,111 | £1,500 |
Tilt and turn windows have a modern design, with several opening options for ventilation and ease of cleaning. They are more expensive than casement windows – with prices between £512 and £990 per window – but are becoming increasingly popular in the UK due to their versatility.
Tilt and turn designs generally have a unique hardware system with multiple locking points that allow them to work in two distinct ways:
Tilt-and-turn windows suit a variety of budgets and architectural preferences, as they’re available with uPVC, aluminium or timber frames in different styles and finishes.
| Bay window frame material | 1,016mm x 914mm | 3,200mm x 1,980mm |
|---|---|---|
| uPVC | £1,700 | £2,800 |
| Aluminium | £3,400 | £5,600 |
| Timber | £5,100 | £8,400 |
Bay windows are one of the most expensive window styles on the market, costing between £1,700 and £8,400 to install. By bowing outwards from the property, they create more interior space and add an interesting visual element to the exterior of the house. Bay windows are available in uPVC, aluminium or timber.
Bay windows form a curved or polygonal shape with three or more window panels arranged at angles. The most common configuration is a rectangular bay, consisting of a large central window with two smaller, angled windows on either side.
The cost of bay windows tends to be higher than that of casement or tilt-and-turn window frames. This is because they are more difficult to install and require more materials.
| Bow window frame material | 1,016mm x 914mm | 3,200mm x 1,980mm |
|---|---|---|
| uPVC | £1,700 | £2,800 |
| Aluminium | £3,400 | £5,600 |
| Timber | £5,100 | £8,400 |
Like bay windows, bow windows extend outwards from your property. They are also expensive – typically costing between £1,700 and £8,400 per replacement window – as they require more materials and take longer to install.
Bow windows extend from the wall rather than the ground. Instead of the more angular look of bay windows, their glass panels form a gentle arc, giving them a unique look
The cheapest option for bow windows is uPVC, but they are also available in timber and aluminium. However, not all manufacturers offer bow windows.
If you know how to measure your windows, it will be easier to estimate the cost of replacing them and compare quotes. It can also simplify the process of ordering new windows online or shopping for blinds or curtains. Don’t worry, though. Your window installer will also take detailed measurements.
If possible, measure your windows from the exterior of your property, using millimetres. Take measurements from the edges of the bricks, as it’s crucial that you measure the window aperture (the hole in the wall that the window frame sits in) rather than the frame itself.
Also, check if the supplier wants you to deduct 5-10mm from your figures to allow for natural shifting.
Here’s a step-by-step guide to measuring your windows:
The main differences between double and secondary glazing are structure and price. Secondary glazing is less expensive, as it doesn’t involve buying completely new windows. However, it’s not as energy efficient as double glazing, so it won’t save you as much on your energy bills. Triple glazing is the most energy-efficient choice, but although the cost of this has decreased recently, it’s still the most expensive option.
Double glazed windows have two panes of glass separated by a spacer bar. The gap between the panes is filled with air or an insulating gas – usually argon – creating a vacuum to keep any warmth inside your home. This design prevents moisture from gathering between the panes, making it more effective at reducing condensation.
Double glazing provides excellent noise reduction and increases the security of your home. With its wide variety of materials, styles and colours, it can also increase your property’s appearance and value.
If the double glazed unit develops a fault, such as leaky seals or a problem with the hardware, it can be replaced. However, if there’s a severe seal failure or the glass is damaged, the whole unit may need to be replaced. This can be both costly and time consuming.
Secondary glazing improves thermal insulation in your home by adding another pane of glass or acrylic to the inside of a single glazed window. However, it’s not as energy efficient as double glazing, and it has an increased risk of condensation.
However, secondary glazing is normally cheaper and easier to install than double glazing, as you don’t need to replace your existing windows. It’s also useful for those in listed buildings or conservation areas, where planning laws may have restrictions on replacing old windows. Secondary glazing is less obvious from the outside, so it helps maintain the original look of such properties. However, it might not be as attractive from the inside.
In the end, the choice between double and secondary glazing will depend on your budget, preferences and needs. Although secondary glazing is cheaper and easier to install, double glazing has more efficient thermal insulation.
While double glazing has two panes and one gas-filled gap, triple glazing has three panes and two gaps. This design provides better energy efficiency, as it’s better at regulating indoor temperatures, keeping your home cooler in the summer and warmer in the winter.
While triple glazing prices were once thought to be much more expensive than those of double glazing, this cost has recently decreased to around only 10 to 20 per cent more. Also, some companies offer a triple glazing upgrade for the same price as double glazed windows.
Several factors can increase the cost of replacing your windows.
Typically, a team of two installers (working at an hourly rate of between £25 and £35 per person) will fit your double glazing, resulting in average labour costs of £500 per day. For a single installer, the day rate ranges from £200 to £280.
The total time to fit replacement windows on an entire property will depend on the number of windows (and their type and size). However, if there are no complications, it usually takes up to three hours to install one window.
Different regions may have varying labour costs. For example, in the UK, prices are typically higher in London and the South East.
Usually, you’ll need to replace your windows after 15 to 20 years. However, watch out for these signs that your windows are losing their efficiency:
Before contacting any double glazing companies, research all the available style options and materials. When comparing different window quotes, consider your requirements, preferences and budget.
When you contact a company, its installers, suppliers or sales representatives will book an appointment to visit your home. Once they arrive, they will, discuss your options, take measurements and provide you with an accurate quote.
Most window companies will make your windows to order with the exact measurements taken during their initial visit. Off-the-shelf window units are unlikely to be an exact fit, so they can cause draughts and dampness. They may also have a reduced lifespan. To avoid such issues, it’s best to use a professional installer.
Be sure to read the fine print before signing a contract, and never let a salesperson pressure you into making a snap decision. Any reputable supplier, such as Anglian, will give you plenty of time to decide if you want to proceed.
Resist the temptation to opt for the cheapest quote, as it may be too good to be true.
If a quote is excessively cheap, your new windows may be made from inferior materials. You could also end up with installation shortcuts or inexperienced installers. Such issues can cause reduced durability, poor insulation or other potential problems, such as condensation between the panes. Your windows should provide comfort and long-term energy savings, so balance cost against quality to avoid unexpected repair bills or premature replacements.
Ask the right questions and compare quotes from reputable companies to ensure your investment in replacement windows is beneficial.
Find the best deal. Everything from the style of the window to your choice of lock determines the final price, so most double glazing companies provide tailored quotes. Also, by getting quotes from several companies, you can see who has the best deal, allowing you to negotiate.
Check that your installer is FENSA or Certass registered. This certification will be essential if you decide to sell your home in the future. A FENSA or Certass certificate means that new installations comply with building regulations and are registered with the local council. These certificates will also protect you if there are any problems with the installation.
To allow you to make an informed decision, any quote for new windows should be as detailed and transparent as possible. A professional installer’s quote should include the following details:
Ask the installer for any clarification you need before you sign the contract. By doing so, you can be confident you’re making an informed decision about which supplier to hire for your windows upgrade.
In the UK, replacement windows can cost an average of £4,000, but the exact cost will depend on your chosen window type and frame material. As each frame material has its own advantages, you’ll need to find a balance between any benefits and the price. Don’t rush your decision, as it’s important that you choose the right installer. Take the time to compare quotes, products and warranties from several window companies, as their prices and product warranties will vary.
To negotiate a lower price for new windows, research the market, understand your requirements, establish a budget, and get multiple quotes by using our simple quote form.
The cost of replacement windows has risen due to increased glass production costs, labour prices, and higher costs for raw materials, and transportation. Homeowners can offset some of these costs with government grants available to those who meet the criteria.
It can be cheaper to replace all your windows at the same time, as it can reduce material costs and save you money on labour. In addition, since windows are the primary source of heat loss in your home, as they become less efficient, your energy bills will increase.
The colour of your windows can affect the overall price. The most affordable option is standard white uPVC windows, but the price can increase if you choose different colours or finishes. For instance, grey uPVC windows can cost around 10 per cent more than white ones, and if you choose a wood grain finish, the total cost can increase by around 10 to 15 per cent.
Choosing expensive windows can save you money over time with superior energy efficiency, improved noise reduction, and features, such as triple glazing. They can also offer better insulation and a variety of styles. Consider these benefits against your budget and needs.
