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Window Replacement Cost Guide 2026: UK Prices for Every Window Type
Quick Answer
Window replacement in the UK costs between £350 and £3,500 per window in 2026, depending on the window type, material, and size. For a full house, expect to pay £2,000-£4,000 for a two-bedroom flat, £4,000-£8,000 for a three-bedroom semi-detached, £8,000-£15,000 for a four-bedroom detached, and £6,000-£12,000 for a Victorian terrace. Prices include supply, installation, VAT, and disposal of old windows.
At a Glance
Planning a window replacement project in 2026 requires accurate, up-to-date pricing information to set a realistic budget and avoid unwelcome surprises. Window costs in the UK vary enormously depending on the type of window, the material chosen, the size of your property, and even your geographical location. This comprehensive cost guide provides detailed pricing for every common window type, broken down by material and specification, along with full-house estimates by property type and regional pricing variations. All prices quoted are inclusive of supply, professional installation, VAT at 20%, and responsible disposal of old windows. These figures are based on current market rates from established UK window companies and are intended as a reliable guide for budgeting purposes. Individual quotations may vary based on access, specification, and local market conditions.
Cost Per Window by Type and Material
The single biggest factor affecting window replacement cost is the combination of window type and material. Here are the 2026 UK average prices per window, fully fitted. uPVC casement windows: £350-£800 depending on size and colour, with white being the most affordable and coloured or woodgrain finishes adding £50-£100. uPVC sliding sash windows: £600-£1,200, reflecting the more complex mechanism. Timber casement windows: £800-£1,500 depending on softwood or hardwood species. Timber sliding sash windows: £1,200-£2,800, with box sash designs at the upper end. Aluminium casement windows: £600-£1,400 depending on size and colour. Georgian-bar windows (any material): £800-£2,000, with the premium reflecting the glazing bar manufacturing. Tilt and turn windows: £500-£1,100, available in uPVC or aluminium. Bay windows: £1,500-£3,500 for a standard three-panel configuration. Triple-glazed windows: add £150-£350 per window on top of the equivalent double-glazed price. These prices represent the middle market; budget options may be 15-20% less and premium brands 20-40% more.
Full House Costs by Property Type
For whole-house window replacement projects, total costs depend on the number and size of windows, the property configuration, and the chosen specification. A two-bedroom flat typically has four to six windows and costs £2,000-£4,000 for uPVC double glazing or £3,500-£7,000 for timber. A three-bedroom semi-detached house usually requires eight to twelve windows, budgeting £4,000-£8,000 for uPVC or £7,000-£14,000 for timber. A four-bedroom detached house typically has twelve to eighteen windows, costing £8,000-£15,000 for uPVC or £14,000-£28,000 for timber. Victorian terraced houses present unique challenges due to their sash windows, bay windows, and potential conservation area restrictions, with typical costs of £6,000-£12,000 for uPVC sash or £10,000-£22,000 for timber sash. Edwardian semi-detached properties with bay windows at ground and first floor are similar to Victorian terraces in complexity, budgeting £6,000-£14,000. These whole-house prices include all windows but exclude doors. Front and back door replacements typically add £800-£3,000 depending on material and style.
Regional Pricing Variations Across the UK
Window replacement costs vary significantly by region, driven by differences in labour rates, property values, and local market competition. London carries the highest premium, with prices typically 15-25% above the national average. This reflects higher labour costs, more expensive parking and access arrangements, and congestion charges for installers. Central London projects can attract premiums of 25-35% for access-restricted properties. The Home Counties, including Hertfordshire, Essex, and Cambridgeshire, sit close to the national average, with prices typically within 5-10% of the figures quoted in this guide. Harrington Windows operates across these counties, and the prices in this guide closely reflect these local markets. The South East outside London is broadly average, while the South West and East Anglia tend to be 5-10% below average. The Midlands and Northern England generally offer the most competitive pricing, with costs 10-15% below the national average. Scotland has comparable pricing to Northern England for most window types, though timber sash replacements in Edinburgh and Glasgow conservation areas can command premiums due to specialist demand.
What Is Included in Window Installation Costs
A comprehensive window replacement quotation should include several elements. The window frames and glazing units are the largest single cost component, typically representing 50-60% of the total price. Professional installation labour accounts for 25-35% of the total, covering the fitting team's time to remove old windows, prepare openings, install new frames, foam and seal, and make good internally and externally. Disposal of old windows and packaging is included by most reputable companies at no additional charge. External finishing, including silicone sealing and any necessary mortar or render repairs around the frame, should be included. Internal finishing with uPVC trims or plaster making good is normally included for uPVC installations but may be charged extra for timber installations requiring bespoke joinery. Scaffolding is an additional cost if required, typically £500-£1,500 depending on the extent of access needed. A FENSA or CERTASS certificate confirming Building Regulations compliance should be issued at no extra charge. VAT at 20% is included in all the prices quoted in this guide.
Factors That Affect Window Replacement Costs
Several factors beyond basic material and type choices can significantly affect your final quotation. Window size is obviously important, with non-standard or oversized windows costing more than standard sizes. Access difficulty is a major factor; windows above ground floor that require scaffolding or cherry picker access add £500-£2,000 to the project. Structural work, such as replacing rotten lintels, damaged sub-sills, or corroded bay window supports, can add £200-£1,000 per window. Conservation area or listed building requirements may dictate specific materials, profiles, and finishes that carry premium pricing. The number of opening sashes affects cost; each opening sash adds hardware, hinges, and manufacturing complexity compared to fixed panes. Glazing specification impacts pricing, with triple glazing, acoustic glass, toughened safety glass, and obscure privacy glass all adding to the base cost. Colour choices matter too, with coloured or woodgrain uPVC costing 10-15% more than white, and non-standard RAL colours on aluminium adding a premium. Finally, the time of year can affect pricing, with autumn and winter being quieter periods when some companies offer discounts of 5-10%.
Return on Investment: Do New Windows Add Value?
New windows are one of the most effective home improvements for adding value to a property. Research consistently shows that new double-glazed windows add 5-10% to a property's value, depending on the condition of the existing windows and the quality of the replacements. For a property valued at £350,000, this represents a potential value increase of £17,500-£35,000, far exceeding the typical cost of £4,000-£15,000 for a full set of new windows. Beyond the capital value increase, new windows reduce energy bills by £100-£300 per year depending on the property and the windows being replaced. Over the 20-30 year lifespan of modern windows, cumulative energy savings of £2,000-£9,000 further enhance the return on investment. New windows also improve the EPC (Energy Performance Certificate) rating, which is increasingly important for mortgage lending and rental properties. Perhaps most importantly, new windows improve the day-to-day comfort and enjoyment of your home through better insulation, reduced noise, improved security, and enhanced appearance, benefits that are genuinely valuable even if they cannot be precisely quantified in monetary terms.
How to Get the Best Value on Window Replacements
Getting good value on window replacements requires balancing quality with cost. Always obtain at least three written quotations from established, FENSA or CERTASS registered companies. Ensure each quotation specifies the same specification so you are comparing like with like, including frame material, colour, glazing type, hardware, and what is included in the price. Be cautious of quotations that are significantly lower than the others, as this may indicate inferior products, substandard installation, or hidden extras that will be charged later. Ask about the profile system being used and check the manufacturer's reputation. Avoid high-pressure sales tactics; reputable companies will give you time to consider their quotation without aggressive follow-up. Consider the timing of your project, as ordering in autumn or winter when demand is lower may secure better pricing. Ask whether a discount is available for a whole-house order rather than doing windows in stages. Check the guarantee offered, looking for a minimum of ten years on frames and five years on sealed units and hardware. Finally, verify that the company will issue a FENSA or CERTASS certificate, which is not just good practice but a legal requirement for window replacements.
Payment, Deposits, and What to Watch Out For
Legitimate window companies typically require a deposit of 10-30% at the point of order, with the balance due upon satisfactory completion of the installation. Be wary of any company asking for more than 50% upfront, as this exposes you to significant financial risk if the company ceases trading before completing the work. Never pay the full balance before the installation is complete and you are satisfied with the workmanship. Pay by credit card where possible, as Section 75 of the Consumer Credit Act provides additional protection for purchases over £100. Check whether the company is a member of a deposit protection scheme or insurance-backed guarantee scheme, such as those offered through the GGF (Glass and Glazing Federation) or Network VEKA. These schemes protect your deposit if the company goes out of business and provide an independent complaints resolution service. Finance options are available from many window companies, typically offering 0% interest over 12-24 months or low-rate finance over longer terms. Always read the finance agreement carefully and check the total amount payable including any interest.
Pros and Cons
Advantages
- New windows add 5-10% to property value, often exceeding the installation cost
- Energy savings of £100-£300 per year reduce the net cost over time
- Improved EPC rating benefits mortgage applications and rental compliance
- Enhanced security, noise reduction, and daily comfort
- Modern windows require minimal maintenance for 20-30+ years
Disadvantages
- Significant upfront investment of £2,000-£15,000+ for a whole house
- Disruption during installation typically lasting 1-3 days
- Cheaper quotations may indicate inferior products or poor installation
- Conservation area and listed building restrictions can increase costs substantially
Cost Guide
As a summary of the key figures in this guide: individual window costs range from £350 for a standard uPVC casement to £3,500 for a large bay window. The most popular choice, a white uPVC casement window, costs £350-£800 fully fitted. For whole-house projects, budget £2,000-£4,000 for a two-bedroom flat in uPVC, £4,000-£8,000 for a three-bedroom semi, £8,000-£15,000 for a four-bedroom detached, or £6,000-£12,000 for a Victorian terrace. Timber and aluminium options cost 50-100% more than uPVC equivalents. Triple glazing adds £150-£350 per window over double glazing. London prices are 15-25% above national averages, while Hertfordshire, Essex, and Cambridgeshire are close to average. Always factor in potential additional costs for scaffolding (£500-£1,500), structural repairs, and bay window roofing.
Is It Right for Your Home?
If your windows are over 20 years old, showing signs of draughts, condensation between the panes, difficulty opening or closing, or visible deterioration, replacement is likely a sound investment. The combination of energy savings, increased property value, and improved comfort makes modern window replacement one of the most cost-effective home improvements available. Start by identifying your priorities: if budget is the primary concern, uPVC casement windows offer excellent performance at the lowest cost. If your property is in a conservation area or you value traditional aesthetics, timber or high-quality flush sash uPVC windows are worth the additional investment. For contemporary properties, aluminium provides a striking modern appearance. Whatever your situation, obtaining multiple quotations from FENSA-registered installers, comparing specifications carefully, and choosing a reputable company with strong guarantees will ensure you get the best value from your window replacement project.
Frequently Asked Questions
For a full set of uPVC double-glazed windows: a 2-bed flat costs £2,000-£4,000, a 3-bed semi £4,000-£8,000, a 4-bed detached £8,000-£15,000, and a Victorian terrace £6,000-£12,000. Timber windows cost 50-100% more. All prices include supply, fitting, VAT, and old window disposal.
A standard white uPVC casement window costs £350-£800 fully fitted in 2026, depending on size. Coloured or woodgrain uPVC adds £50-£100. A uPVC sash window costs £600-£1,200. These prices include the window, installation, VAT, and disposal of the old window.
Yes, typically 50-100% more expensive. A timber casement costs £800-£1,500 compared to £350-£800 for uPVC. A timber sash costs £1,200-£2,800 compared to £600-£1,200 for uPVC. However, timber windows last longer (40-60 years vs 20-30 years) and add more character and value to period properties.
Aluminium casement windows cost £600-£1,400 per window fully fitted. They are more expensive than uPVC but offer slimmer sightlines, a contemporary aesthetic, and exceptional durability (30-45 year lifespan). Dual-colour options and non-standard RAL colours add a premium of £50-£150 per window.
A standard three-panel bay window costs £1,500-£2,500 in uPVC, £2,500-£4,500 in timber, or £2,500-£3,500 in aluminium. Additional costs may include bay roof replacement (£300-£1,200) and structural repairs (£500-£2,000). A typical Victorian terrace with two bays costs £4,000-£8,000 in uPVC.
Triple glazing adds £150-£350 per window over double glazing, improving U-values from 1.2-1.4 to 0.8-1.0 W/m²K. For a 10-window house, the extra cost is £1,500-£3,500. Energy savings are £30-£60 per year beyond double glazing, so payback takes 25-60 years. It is most worthwhile for exposed, north-facing, or noise-affected properties.
All prices in this guide include VAT at 20%. Always check whether quotations you receive include or exclude VAT, as this can make a significant difference to the final cost. Some companies quote ex-VAT to make their prices appear more competitive.
Yes, many window companies offer better pricing during autumn and winter (October-February) when demand is lower. Discounts of 5-10% are common during quieter periods. Lead times are also shorter, meaning your windows can be manufactured and installed more quickly.
A typical deposit is 10-30% of the total order value. Be cautious of any company requesting more than 50% upfront. Pay by credit card for Section 75 protection and check that the company offers deposit protection or insurance-backed guarantees. The balance should be due only upon satisfactory completion.
Yes, new double-glazed windows typically add 5-10% to a property's value. For a £350,000 home, that is a potential increase of £17,500-£35,000, usually exceeding the installation cost. New windows also improve EPC ratings, reduce energy bills by £100-£300 annually, and make properties more attractive to buyers.
A typical window replacement project takes 1-3 days depending on the number of windows. A single window takes 1-2 hours to install. A full house of 8-12 windows is usually completed in 1-2 days. Bay windows and sash windows take longer than standard casements. Scaffolding erection adds an additional half day.
FENSA is a government-authorised scheme that allows registered installers to self-certify that window replacements comply with Building Regulations. A FENSA certificate is essential for future property sales. If your installer is not FENSA or CERTASS registered, you must obtain separate Building Control approval at additional cost (typically £200-£400).
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