How Much Does It Cost to Replace Windows?
What window replacement costs in the UK, and what to consider before you commit.
Window replacement costs in the UK typically range from £400 to £1,500 per window, depending on the material, style, and size. Whether you’re replacing a single window or the whole house, knowing what drives the price helps you make a better decision. Here’s a clear breakdown.
At a glance
- Window replacement costs between £400 and £1,500 per window, depending on material and style
- uPVC is the most affordable option, starting at around £400 per window
- Energy-efficient glazing costs more upfront but can reduce heating bills over time
- Building insurance typically covers accidental damage and storm damage to windows, but not wear and tear
- Always use a FENSA or CERTASS-certified installer to comply with building regulations
Average window replacement costs
Replacing a single window in the UK costs between £400 and £1,500 depending on the material. For a typical house, replacing all windows with standard double glazing usually comes in at £1,200 to £6,000 in total, depending on the number of windows and the complexity of the job.
Here’s a rough guide by material:
| Material | Estimated cost per window |
|---|---|
| uPVC | £400–£600 |
| Timber | £700–£1,000 |
| Aluminium | £800–£1,500 |
According to Checkatrade, the average cost to replace all windows in a three-bedroom semi-detached house is around £4,000 to £5,000 for uPVC double glazing. Larger properties or those requiring bespoke sizes will sit considerably higher.
What affects the cost?
Several factors influence the final price beyond just the material:
- Window style: Casement windows are generally the most affordable. Bay windows, sliding sash windows, and other more complex styles cost more due to the additional materials and fitting time involved.
- Size: Larger or non-standard windows cost more than standard sizes. Custom or made-to-measure windows carry an additional premium.
- Glazing type: Double glazing is standard. Triple glazing costs more upfront but performs better thermally. A-rated glass adds to the cost but can reduce energy bills over time.
- Installation complexity: Difficult access, unusual wall constructions, or properties requiring planning permission before windows can be replaced all add to the price.
- Location: Labour rates in London and the South East are typically higher than elsewhere in the UK.
Pros and cons of window materials
uPVC
uPVC is the most popular choice for UK homes. It’s cost-effective, low-maintenance, thermally efficient, and weatherproof. The main drawback is aesthetics. uPVC doesn’t suit every property style, particularly older or period homes where timber frames are more appropriate.
Timber
Timber frames add character and are often the right choice for period properties or where planning restrictions apply. They require more upkeep than uPVC, including periodic repainting and treatment, and cost more both to buy and install. If you’re in a conservation area, timber may be a requirement rather than a preference.
Aluminium
Aluminium frames are slim, durable, and well-suited to contemporary homes. They’re more expensive than uPVC but offer excellent longevity and very low maintenance. The slim sightlines also let in more light than thicker uPVC or timber frames, which is a practical advantage in smaller rooms.
Energy efficiency
Upgrading to energy-efficient windows reduces heat loss and draughts, which lowers your heating bills and makes the home more comfortable year-round. The Energy Saving Trust estimates that replacing single-glazed windows with A-rated double glazing can save between £95 and £115 per year on energy bills in a typical semi-detached home.
A few things to look for when comparing windows:
- Energy rating: Windows are rated from A++ to E. A-rated or above is recommended.
- U-value: This measures how much heat the window loses. The lower the U-value, the better the insulation.
- Triple glazing: Worth considering if you’re in a particularly cold or exposed location, or if noise reduction is a priority.
Energy-efficient windows can also improve your property’s Energy Performance Certificate (EPC) rating, which is increasingly relevant if you’re planning to sell or let the property.
Does home insurance cover window replacement?
Building insurance typically covers windows that are damaged by sudden and unexpected events, such as storm damage, accidental breakage, or vandalism. If a storm blows debris through a window or a break-in causes damage to the frame, your buildings insurance should cover the repair or replacement.
What buildings insurance won’t cover is gradual deterioration, condensation between panes, or windows that have simply reached the end of their useful life. These are considered maintenance issues and the homeowner’s responsibility.
Choosing a reliable installer
Window installation is regulated in the UK, and using a certified installer matters both for quality and legal compliance.
- Use a FENSA or CERTASS-certified installer. Both schemes certify that the installation meets building regulations and issue a compliance certificate. You’ll need this certificate if you sell the property, so don’t skip it.
- Get at least three quotes. Compare what’s included in each, not just the headline price.
- Check reviews on Checkatrade or Rated People.
- Confirm the warranty on both the window units and the installation. Most reputable installers offer a minimum ten-year guarantee on frames and sealed units.
- Never pay the full amount upfront. A deposit is standard, but full payment before completion is not.
You can find FENSA-certified installers in your area at fensa.org.uk.
Before we go
Window replacement is a significant investment, but the right choice for your property can improve comfort, reduce energy bills, and add long-term value. Get multiple quotes, use a certified installer, and check your buildings insurance policy before starting work if existing windows have been damaged. Acting on damage sooner rather than later keeps both the repair costs and any secondary damage to a minimum.
Window replacement FAQs
What is the average cost to replace a single window in the UK?
Replacing a single window typically costs between £400 and £1,500 depending on the material, style, and size. uPVC is at the lower end, aluminium at the higher end. Labour costs also vary by region, with London and the South East generally sitting above the national average.
Are uPVC windows cheaper than wooden windows?
Yes, significantly. uPVC windows start at around £400 per window, while timber frames typically cost between £700 and £1,000 per window. Timber also requires more ongoing maintenance, adding to the long-term cost. That said, timber is often the most appropriate choice for period properties or where planning restrictions apply.
Does home insurance cover broken or damaged windows?
Building insurance covers windows damaged by sudden and unexpected events, such as storms, accidental breakage, or vandalism. Condensation between panes, gradual deterioration, and age-related failure are not covered, as these are maintenance issues.
Are triple-glazed windows worth the cost?
Triple glazing performs better thermally and acoustically than double glazing, but the additional cost doesn’t always translate to proportional energy savings in the UK climate. It’s most worth considering in particularly cold or exposed locations, for rooms facing a noisy road, or where maximum insulation is a priority. For most UK homes, A-rated double glazing offers a strong balance of cost and performance.
What certifications should I look for in a window installer?
Look for installers certified by FENSA or CERTASS. Both schemes ensure the installation meets building regulations and issue a compliance certificate, which you’ll need when selling the property. Always ask for the certificate once the work is complete.
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