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The cost of double glazed windows is offset by a reduction of up to £260 on your annual heating bill, making them a smart investment, while window grants can further maximise your savings. Double glazing is a valuable upgrade for any home, offering increased energy efficiency, improved soundproofing and enhanced security.
To provide the most accurate and up-to-date insights, our windows experts consulted the best double glazing companies, compared quotes, and analysed customer reviews. This approach ensures you can choose the best quality and value for your home.
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To install uPVC double glazing for every window in a typical three-bedroom property, it will cost around £4,000. However, the window size, style, frame material and glass type will affect the quote. Although the number of windows is also a factor, many installers offer discounts if you replace all your windows at once.
| Type of three-bedroom property | Number of casement windows | uPVC | Aluminium | Timber |
|---|---|---|---|---|
| Flat | 4 | £2,108 | £3,200 | £4,800 |
| Terrace | 6 | £3,600 | £5,000 | £8,000 |
| Semi-detached | 7 | £4,000 | £7,500 | £11,500 |
| Detached | 15 | £7,500 | £12,000 | £18,000 |
uPVC frames are a popular, cost-effective option because they’re durable, require minimal maintenance and offer solid thermal performance. The average cost for uPVC double glazing is around £500 per window, depending on the size, style, and glazing options. Prices are also influenced by the number of windows, the complexity of installation, and additional features such as specialised locking mechanisms, coloured or wood effect frames.
| Window material | Average cost for a casement window |
|---|---|
| uPVC | £525 |
| Aluminium | £800 |
| Timber | £1,200 |
Aluminium windows are more expensive than uPVC, with average prices around £800 per window, depending on size and style. Their thinner frames allow for larger glass areas, enhancing aesthetics but increasing costs. Despite the higher price, aluminium windows offer long-lasting performance, low maintenance, and a sleek, modern look, making them a valuable investment.
Composite frames are made from a blend of materials—often timber and uPVC—offering the benefits of both materials. Prices vary depending on the specific components used. A popular combination is a uPVC exterior frame and a timber interior, where the uPVC provides low maintenance, and the timber adds a timeless charm to your home.
Wooden window frames are the most expensive option, with average prices around £1,200 per window. They offer excellent insulation, and many people love their classic look. However, timber requires more maintenance than other materials to prevent issues like rot and insect damage, which increases the overall cost. With regular maintenance, timber frames can outlast both uPVC and aluminium.
Different window styles have varying levels of complexity when it comes to manufacturing and installing them, and this influences the price.
Large windows need more materials for the frame and glass, which results in higher manufacturing costs.
Oversized windows can also have higher labour costs because they are more difficult and time-consuming to install than smaller ones. For instance, the property may need structural modifications to accommodate them, such as enlarging an existing window opening. Also, bigger windows will be heavier, so more people may be required to install them.
| Window style and material | Small* | Medium** | Large*** |
|---|---|---|---|
| uPVC casement | £525 | £580 | £620 |
| uPVC sash | £500 | £580 | Typically unavailable in this size |
| uPVC tilt and turn | £600 | £695 | £750 |
| Aluminium casement | £800-£1,000 | £950-£1,150 | £1,200-£1,250 |
| Timber casement | £1,500 | £1,700 | £1,850 |
| Timber sash | £1,500-£1,700 | £1,700-£1,900 | Typically unavailable in this size |
It may be worth considering a specialised glass for increased insulation or if you want highly break-resistant glass, but these options can increase the cost.
Low-emissivity (low-E) glass is coated with a transparent, microscopic layer that reflects heat. Although this usually costs more than standard glass, low-E glass improves the window’s insulation, keeping your home cooler in the summer and warmer in the winter.
Another costly option is toughened or tempered glass, which is stronger and safer than regular glass. If it breaks, it shatters into small, blunt pieces instead of large, sharp shards, reducing the risk of injury.
With a layer of plastic between two panes of glass, laminated glass is highly resistant to breakage. Although more expensive, it provides additional benefits such as noise reduction and UV protection.
The project’s total cost depends on the number of windows you’re installing or replacing.
However, while the total price increases, it might be more cost efficient to install several windows at the same time. As the installers are already on-site and have their equipment set up, it might not take significantly longer to install more windows, meaning labour costs could be lower. As a result, larger projects may have a reduced cost per window.
Some double glazing companies and suppliers have discounts for larger orders, so if you buy several windows at once, the per-window cost might be lower. However, such potential discounts depend on the specific supplier or contractor, so they vary greatly.
To keep costs down, many homeowners only replace certain windows, such as those facing the street. However, to see if this approach is actually cheaper, be sure to compare quotes, taking any discounts for a multiple window installation into account.
Labour costs for installing double glazed windows can vary widely depending on the region and the size of the project. On average, labour is more expensive in areas like London and the South East, where living expenses and demand are higher. Local installers outside major cities often charge less, making them a more affordable option. Additionally, small, independent installers may offer better deals compared to national companies, as they have fewer overhead costs. It’s recommended to get multiple quotes to find the best price for your area.
Most double glazed windows take one to two hours to install, with a two-person team typically completing installation in a three-bedroom house over two days.
Several factors can affect the time taken to install windows, including:
In the UK, the average cost of double glazing a three-bedroom house is around £4,000. However, several factors influence the price.
The overall cost of double glazed windows for an entire house can vary on factors such as the number of windows, size, material, and the chosen style. For a typical three-bedroom house, the average costs are as follows:
Another important factor is the size and style of the windows. Many homeowners choose more attractive designs for the front of the property and less expensive options—like casement windows—for the rear. Additionally, the complexity of the installation can also affect double glazing costs. For example, older properties with uneven frames may require specialised expertise and equipment, which can increase costs.
Lastly, your choice of supplier can also influence the final price. Local installers often charge less than national suppliers so it’s advisable to obtain multiple quotes to compare prices and options.
Double glazing is a valuable investment, and its extensive benefits include:
With potential energy bill savings of up to £260 annually, such benefits ensure a rewarding return on investment.
The average double glazing cost and payback period for a three-bedroom property:
| Material | Average cost of double glazing a three-bedroom property | Average payback period |
|---|---|---|
| uPVC | £4,000 | 15 years |
| Aluminium | £8,000 | 25 years |
| Timber | £10,500 | 40 years |
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Mark McCluggage, director at Sheerwater Glass LTD, told our experts:
“Most double glazing companies have to pay to provide insurance-backed warranties and register their windows with the Fenestration Self-Assessment Scheme (FENSA). However, once those fixed calculations are factored into the prices, there’s room for flexibility, meaning homeowners can often negotiate better quotes instead of having to accept the first figure given.”
Although the cost of double glazed windows has remained relatively stable for the last few years, several factors could impact prices in the future. These include:
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The best time to buy double glazing depends on your circumstances. Off-peak seasons (typically from autumn) can be more cost effective, as companies usually offer discounts due to lower demand. Additionally, installing new windows before winter arrives will allow you to benefit from energy savings during the colder months.
Although both double and triple glazing enhance energy efficiency and comfort, they differ in construction and cost. Double glazing’s two glass panes and gas-filled gap reduce heat loss and noise. Triple glazing adds an extra pane and gas layer, improving soundproofing and insulation, which is especially useful in colder regions. However, triple glazing is more expensive, and their extra weight requires stronger frames.
When negotiating with a double glazing salesperson, show that you’ve done your research by outlining your requirements and budget. Ask for discounts, reference competitor quotes, and remember that prices are often negotiable. Additionally, be prepared to walk away if the deal doesn’t meet your expectations, as this can sometimes prompt a better offer.
It may be time to replace your windows if you’re having trouble opening them or if you notice draughts, recurring condensation, visible damage or high energy bills. These problems indicate poor insulation, seal failure or structural issues.
Cheap double glazing often involves lower-quality materials or installation by less qualified teams, leading to issues like draughts, leaks, and poor insulation, which may increase energy bills. Additionally, these windows tend to have a shorter lifespan and often come with limited warranties. Investing in higher-quality double glazing provides better insulation, increased durability, and long-term savings on energy costs.
