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The cost of double glazing is easily offset by the savings delivered on your heating bills. Alongside other benefits, such as sound proofing, and increased security, replacement windows make a wise investment. Double glazing prices are based on window design and materials, so it’s important to explore different options. Additionally, window grants are available to help maximise your savings.
Our experts have thoroughly researched pricing, cost-saving measures, and the top double glazing companies to help you make a well-informed decision.
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For a typical three-bedroom property, installing uPVC double glazing for every window will cost around £4,500. However, the size of the windows, and your choice of frame material and glass type, will determine the cost. Although the number of windows is also a factor, installers offer discounts for multiple upgrades.
| Type of three-bedroom property | Number of casement windows | uPVC | Aluminium | Timber |
|---|---|---|---|---|
| Flat | 4 | £2,108 | £3,200 | £4,800 |
| Terrace | 7 | £3,689 | £5,600 | £8,400 |
| Semi-detached | 10 | £4,500 | £8,000 | £12,000 |
| Detached | 15 | £7,500 | £12,000 | £18,000 |
The most cost-effective option is uPVC frames, which are also the most popular choice. As they’re durable, they don’t need much maintenance, and they offer good thermal performance.
| Window material | Average cost for a casement window |
|---|---|
| uPVC | £525 |
| Aluminium | £800 |
| Timber | £1,200 |
Aluminium windows are usually more expensive than uPVC ones. They aren’t as insulating as wood or uPVC, but they’re strong and require little maintenance. For oversized windows that require more structural support, aluminium can be a good choice. Composite frames are made from a blend of materials – often timber and uPVC – so they vary in price depending on the specific components used. These composite frames are designed to provide the benefits of both materials. For example, timber and uPVC composite frames have the aesthetic appeal of natural wood, but they require lessmaintenance while still providing good insulation.
Wooden window frames are usually the most expensive option. While they provide excellent insulation and have the classic look that many people prefer, they need more maintenance to prevent issues such as rot or insect damage.
Different window styles have varying prices. This is due to the different levels of manufacturing and the complexity of the installation.
Fixed windows and casement windows are the easiest and cheapest options. While fixed windows only open from a single point – usually the side – casement windows may include the popular awning design, which is hinged at the top and opens outwards, creating an overhang. Sliding sash or tilt and turn designs require more moving parts to allow them to open and close, so they usually have a higher price tag.
The most expensive options are specialised architectural window styles, such as bay or bow windows. These designs consist of several units – typically casement or sash – and they project outwards from the home’s exterior. If you need custom frames, such as unusually large or nonstandard shapes, this can increase the cost. Such windows can also be expensive to install because of the additional design and manufacturing work required.
Bigger windows have higher manufacturing costs because they require more materials for the frame and glass.
Also, since oversized windows are often more complex, they can be time-consuming to install, leading to higher labour costs. For instance, due to their size and weight, larger windows usually require more people to install them. In some cases, structural modifications may be needed to accommodate large windows, especially if the installers need to enlarge an existing window opening.
| Window style and material | 600mm x 900mm | 900mmm x 1,200mm | 1,200mm x 1,200mm |
|---|---|---|---|
| uPVC casement | £500 | £580 | £620 |
| uPVC sash | £500 | £580 | N/A |
| 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 | N/A |
Specialised glass can bring the additional benefits of increased insulation or resistance to breaking, but these options can increase the cost.
Low-emissivity (low-E) glass is coated with a transparent, microscopic layer that reflects heat. This improves the window’s insulation, so your home stays cooler in the summer and warmer in the winter. However, low-E glass generally costs more than standard glass.
Another costlier option is toughened or tempered glass, which is stronger and safer than regular glass. This glass reduces the risk of injury because if it breaks, it shatters into small, blunt pieces instead of large, sharp shards.
Laminated glass has a layer of plastic between two panes of glass, which makes it really difficult to break. Its design also provides additional benefits, such as noise reduction and UV protection, but it’s more expensive than standard glass.
The project’s total cost depends on how many windows you’re installing or replacing.
However, while the total price increases when installing multiple windows at the same time, it may be more cost-efficient. For instance, labour costs may be lower, as the installers are already on-site with their equipment, so they may need less time to install your windows. So, for a larger project, the cost per window could decrease.
Also, 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, any discounts depend on the specific supplier or contractor.
As the final cost will depend on whether you replace all the windows in your home or just a few, it’s worth considering if you need to upgrade every window. If your windows are old or in poor condition, it makes sense to replace them all at once. After all, if your windows don’t operate properly, that can pose a safety risk in an emergency.
If only some of your windows are damaged, you might decide to just replace those ones. Weather exposure often causes the windows on one side of a house to experience more wear and tear. As these windows are likely to be less energy efficient, this may increase your household bills.
Triple glazing costs 10 to 20 per cent more than double glazing. However, it provides increased insulation, making it attractive for properties in colder climates (such as in Scotland or the north of England). When you request a quote for double glazing, some suppliers give discounted (or free) upgrades to triple glazing.
In the UK, the average cost of double glazing a three-bedroom house typically ranges from £4,000 to £7,000. However, the price will be influenced by several variables.
One of the main considerations is the number of windows you wish to replace. Some suppliers offer discounts for a full set of windows, but you may decide that not every window needs replacing.
The size and style of the windows is an equally important factor. Many homeowners select more aesthetically pleasing styles for the front of the property, saving the less expensive options (such as casement windows) for the rear. Double glazing costs are also impacted by the complexity of the installation and the choice between a local or national window supplier.
Double glazing is a valuable investment, and its extensive benefits include:
The potential energy bill savings of up to £235 annually 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 | £4,500 | 19 years |
| Aluminium | £8,000 | 25 years |
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Mark McCluggage, director at Sheerwater Glass LTD, explained that most double glazing companies must pay to provide insurance-backed warranties and register their windows with the Fenestration Self-Assessment Scheme (FENSA). However, after such fixed calculations are factored into the price, there’s room for flexibility. This means that instead of having to accept the first figure given, homeowners can often negotiate better quotes.
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 salesman, be clear about your requirements and budget, as this shows you’re informed and serious.
Replace your windows if you notice:
Buying cheap double glazing can be risky, as lower-quality materials and poor installation can lead to issues such as leaks, draughts and reduced insulation. In turn, this results in reduced comfort, higher energy bills and a shorter window lifespan, so you’ll likely need to replace the windows sooner. Budget window options often come with limited warranties, so you have minimal protection if problems arise. By investing in higher-quality double glazing, you can receive better insulation, durability and long-term savings.
