- It costs between £520 and £800 to install one uPVC sash window
- It costs roughly £5,400 to install uPVC sash windows in a three-bedroom house
- Installing a uPVC sash window can take between a couple of hours to a day
On average, uPVC sash windows cost between £520 and £800 per window, making them one of the most affordable ways to upgrade your home’s look and energy efficiency.
That might sound like a lot, but according to the Energy Saving Trust, replacing single-glazed windows with A-rated double glazing in a typical gas-heated, semi-detached home could save you £140 per year on energy bills.
Plus, energy-efficient improvements like this could boost your property’s value by up to 10%. Adding double glazing to your home will also help it stay warmer for longer, improve its appearance, and boost security, but the upfront cost can be steep.
Already sold? Then just enter a few details into our quick quote tool. We’ll connect you with trusted suppliers who can provide free, no-obligation quotes tailored to your home.
What type of double glazing do you need?
Get startedHow much do uPVC sash windows cost?
In the UK, installing uPVC sash windows costs between £520 and £800 each. Although they’ve become more affordable over time, the cost can increase quickly. However, double glazing grants can help subsidise the costs.
The table below gives you a rough idea of the cost of replacing all of your windows.
| Type of home | Number of bedrooms | Windows needed | Average cost of sash style uPVC windows |
|---|---|---|---|
Flat | 2 | 4 | £2,400 |
Terraced | 2 | 5 | £3,000 |
Semi-detached | 2 | 7 | £4,200 |
Semi-detached | 3 | 9 | £5,400 |
Detached | 3 | 12 | £7,200 |
Detached | 4 | 15 | £9,000 |
*Prices courtesy of CheckaTrade, May 2025. Costs are based on a 500mm x 500mm sliding sash window, with an average of £600 per window.
Want a better idea of how much you’ll need to pay for a new set of windows? Use our double glazing cost calculator below to find out.
Are uPVC sash windows expensive to maintain?
On average uPVC sash windows will cost anything from £160 and £770 to repair, with this price being lower than you might expect because of their durability. However, they can, and do, get damaged and old over time.
Unlike wooden window frames, uPVC is weatherproof and won’t need annual treatment. However, since sash window panes slide over each other, there might be some wear and tear over time—the movement and friction might lead to some issues.
When it comes to repairing a uPVC sash window, the exact cost will depend on the issue itself. To give you a rough idea of what to expect, we’ve listed some of the most common types of sash window repair costs below.
| Repair type | Average cost |
|---|---|
Sill replacement | £240 |
Sill splice | £180 |
Stiles/front cheeks | £180 |
Replacement sash | £335 |
Draught proofing | £318 |
Sash window refurbishment | £770 |
*Data from CheckaTrade, May 2025.
If your sash windows have worn down over time, it might be worth looking into getting them refurbished rather than repeatedly replacing parts. However, bear in mind that this isn’t a cheap procedure—the average sash window restoration costs around £770 per window.
Which type of sash window should I choose?
- Box Sash vs. Spring Sash: Traditional box sash windows use weights and pulleys, offering classic appeal ideal for period homes. Spring sash windows use a modern spring mechanism, typically easier to install and maintain.
- Timber, uPVC, or Aluminium Frames: Timber offers authenticity and great insulation, but requires more upkeep. uPVC is low-maintenance and cost-effective. Aluminium provides a sleek, modern look with high durability.
- Brand Reputation: Choose established brands with strong reviews and certifications (like FENSA or BSI). A trusted manufacturer ensures better quality, aftercare, and warranty support.
- Energy Efficiency: Look for double or triple-glazing windows, draught-proofing, and low U-values. These features help reduce heat loss and cut energy bills.
- Security Features: Modern sash windows often include key-lockable restrictors, reinforced frames, and toughened glass, which is important for peace of mind, especially on ground floors.
Which type of uPVC sash window is the most expensive?
There’s no set price for windows, but bay windows are usually the most expensive.
Overall, the price of a sash bay window depends on its number of sections. On average, a three-section bay window costs £1,250, a four-section one costs £1,650, and a five-section one costs closer to £2,150.
Despite the steep price, many homeowners value bay windows because of their aesthetics, ability to let in more sunlight and airflow, and increased property value.
Wooden windows are typically more expensive than uPVC ones, which is why some people get uPVC windows with a wood effect – it gives the illusion of a wooden frame at a more affordable price.
If you like the sound of a uPVC sash window with a wood effect, you’ll still have to be willing to pay a little extra. Check out the table below to compare how much more expensive uPVC sash windows are with a wood effect.
| Type of sash window | Size of window | Average cost |
|---|---|---|
White uPVC | 500mm x 500mm | £520–£625 |
White uPVC | 1,000mm x 500mm | £600–£720 |
Wood effect uPVC | 500mm x 500mm | £625–£720 |
Wood effect uPVC | 1,000mm x 500mm | £700–£800 |
*Data courtesy of CheckaTrade, May 2025.
What type of double glazing do you need?
Get startedWhat affects the price of uPVC sash windows?
There’s no one-size-fits-all when it comes to windows. Generally, the cost of installing uPVC sash windows depends on:
- The size of the window pane – The bigger the window, the higher the price
- The style of the window – Installing sash bay windows will be more pricey
- Any added effects – You might have to pay an extra £100-£150 for a wood effect on a uPVC frame
- The number of windows being fitted – The more windows, the higher the price
- The area that you live in – Window installations are usually more expensive in London, compared to the rest of the UK
- The supplier and installer – Different suppliers and installers charge different rates, which means it’s a good idea to shop around for the best rate before committing to a price
- Any additional features – Certain types of glass, glazing bars, and specialist sash window locks will increase the price
How long does it take to install uPVC sash windows?
Installing a uPVC sash window can take anywhere between a couple of hours and a day, depending on a range of factors including the size and type of window.
The number of installers working on the windows will also speed up or slow down the installation process.
Due to their intricate design, bay windows typically take the longest to install—expect half a day to a full day.
One way to cut costs is to install the double glazing yourself, but we don’t recommend this—you could damage your property and even injure yourself.
Summary
- Most UK homes are suitable for uPVC sash windows; you could save up to £195 a year by putting them in.
- Upgrading worn-out windows for these visually pleasing ones will increase property value, reduce energy bills, and reduce household emissions.
- Instead of trawling through installers, compare the best double glazing on the market by entering a few details about your home in our easy-to-use quote tool. We’ll pass on your details to our expert suppliers, who’ll contact you with free, tailored quotes.
