How Much Does Double Glazing Cost in 2026?
In 2026, the most useful way to budget is to treat window replacement as a range rather than a single number. For standard fitted units, a typical casement window is around £300-£600, a sash is £600-£1200, a bay is £800-£1500, and tilt and turn is £400-£700. These figures usually assume normal access and include supply plus installation, but not every quote includes disposal of old frames, interior finishing, scaffold access, or upgraded hardware. If you compare offers line by line, you can see why two quotes that look similar on the surface can end up £1,500 apart on a medium project.
At whole-home level, the numbers also vary with size and specification. For a common 3-bedroom property with 6-8 windows, a realistic installation-inclusive range is £3000-£7000. For larger homes or premium specs, total cost can reach £10,000. That wider upper limit is usually linked to timber frames, complex bay and sash combinations, acoustic or laminated glass upgrades, or triple glazing. A realistic target is to shortlist products by thermal performance and installer quality first, then optimise price second. The cheapest window is rarely the best value over ten to twenty years if seals, locks, hinges, or installation standards are weak.
Per-Window Double Glazing Prices (Installed)
| Window type | Typical installed cost | Why price changes |
|---|---|---|
| Casement | £300-£600 each | Most common style, usually best value for standard openings. |
| Bay | £800-£1500 each | Multiple panes, angles, larger frame areas, more labour. |
| Sash | £600-£1200 each | Sliding mechanism and heritage styling increase cost. |
| Tilt and turn | £400-£700 each | More hardware complexity than basic casement designs. |
Casement windows: the baseline option
Casement units stay the market baseline because manufacturing is standardised, fitting is straightforward in most properties, and the style suits both modern and traditional elevations. In practical terms, the £300-£600 range usually covers standard white uPVC with mainstream hardware and low-emissivity glazing. Prices push toward the top of the band where dimensions are large, glass specs are upgraded, or external access is awkward. Casements are often the best starting point for quote comparisons because they give you a clear benchmark against which premium styles can be judged.
Bay windows: more structure, more labour
Bay replacements cost more because you are not buying one simple rectangular unit. You are paying for multiple linked frames, corner posts, wider cills, and longer fitting time. A bay at £800-£1500 is normal in 2026, but costs can climb when structural condition is poor or when decorative interior boards and trim need careful restoration. If your bay has historical detailing, ask the installer to separate structural work from glazing work in the quote so you can compare like-for-like. This is one of the easiest places for hidden costs to appear late in the process.
Sash windows: style and mechanism drive price
Sash windows in the £600-£1200 range are popular in period streets, conservation-sensitive areas, and homes where owners want a traditional look without sacrificing efficiency. The cost premium comes from balances, sliding hardware, tighter manufacturing tolerances, and sometimes bespoke dimensions. Not all sash products are equal: sightlines, run smoothness, locking quality, and draft control vary widely between brands. If your priority is appearance from the street, ask for close-up examples and check how the frame profile looks when shut, not just brochure photos of open samples.
Tilt and turn: practical ventilation and easy cleaning
Tilt and turn windows usually sit between casement and sash on price, commonly £400-£700 installed. They are popular in upper floors and modern apartments because inward opening simplifies cleaning from inside and tilt mode supports controlled background ventilation. Hardware quality matters here; cheaper mechanisms can feel loose after a few seasons. Ask the installer about hinge warranty periods and replacement part availability. A small upfront increase for robust hardware often protects against repeat callout charges later, especially in heavily used rooms like kitchens and bedrooms.
3-Bedroom House Cost: 6-8 Windows at £3000-£7000
A practical planning range for a standard UK 3-bedroom house is £3000-£7000 including installation for 6-8 windows. The lower part of that band is usually linked to straightforward uPVC casements with standard white finishes, while the upper part often reflects mixed styles, better hardware, tougher access, and upgraded frame finishes. If your project includes larger openings, bays, or sash replacements, costs rise quickly because material volume and labour time both increase.
You may also see total figures around £8,000 to £10,000 when the specification shifts to premium timber, high-end aluminium systems, acoustic packages, or whole-home triple glazing. This does not mean every high quote is poor value, but it does mean you should request an itemised schedule and compare each cost driver separately. A transparent quote should show frame type, glass spec, opening style, trickle vents, installation, finishing, and waste removal as distinct lines.
| Project profile | Window count | Typical total installed cost |
|---|---|---|
| Budget-conscious uPVC double glazing | 6 windows | £3000-£4500 |
| Mixed styles (casement + sash/bay) | 7 windows | £4500-£7000 |
| Premium frames and/or triple glazing | 8 windows | £7000-£10000 |
When comparing total house prices, always ask whether the installer has included internal making-good, external trim, and scaffold allowance where required. These are common points where an attractive headline quote can increase later. In procurement terms, the most dependable approach is to compare three fully itemised offers, each based on the same scope and the same list of assumptions.
What Pushes Quotes Up or Down?
Window replacement is not priced by glass alone. Installers price risk, labour time, logistics, and aftercare obligations. That is why apparently similar projects can differ widely in cost. The biggest variables are opening size, style complexity, frame material, glazing specification, access constraints, and warranty scope. Regional labour rates can also move totals by hundreds of pounds, particularly for larger homes.
- Large or non-standard openings generally cost more than standard modular sizes.
- Upper-floor access, restricted parking, and scaffold requirements can add significant labour overhead.
- Premium finishes, custom colour foils, and woodgrain effects increase frame cost.
- Acoustic, laminated, or solar-control glass options raise per-unit pricing.
- Longer warranty periods and higher service standards can justify a higher upfront quote.
- Disposal, plaster repairs, and trim replacement are often optional extras unless explicitly included.
uPVC vs Aluminium vs Timber Frames
Frame choice has a direct impact on upfront spend and lifetime ownership cost. In most projects, uPVC delivers the lowest initial cost and remains the most common option for straightforward efficiency upgrades. Aluminium usually commands a premium but offers narrow sightlines, strong rigidity, and a modern appearance that suits contemporary extensions. Timber is often the most expensive route at purchase and in maintenance, but it is still preferred for certain period properties and homeowners prioritising traditional aesthetics.
| Frame material | Typical cost level | Strengths | Trade-offs |
|---|---|---|---|
| uPVC | Lowest | Affordable, low maintenance, good thermal performance. | Chunkier profiles on some systems, less premium look. |
| Aluminium | Medium to high | Slim frames, durable, modern finish, strong structural performance. | Higher cost, can require careful thermal break specification. |
| Timber | High | Traditional appearance, suitable for heritage-sensitive streets. | Higher price and ongoing maintenance requirements. |
If budget is your primary objective, uPVC usually wins on cost-per-performance. If visual finish and profile depth are high priorities, aluminium can justify the premium. Timber is often chosen less for payback and more for style, planning context, or matching existing architecture. From a value perspective, make decisions based on total lifetime cost, not just purchase price. A cheaper product that needs early adjustments, seal replacements, or repeated callouts can quickly erase the initial saving.
Double vs Triple Glazing in the UK
Double glazing is still the standard choice for most UK homes because it balances cost, efficiency, and practical payback. Triple glazing can improve thermal performance and internal comfort, especially in colder exposed locations, but typically increases project cost by around 15%-30%. Whether that uplift is worthwhile depends on property type, existing insulation levels, orientation, and how long you plan to stay in the home.
For many households, investing in high-quality A-rated double glazing with robust frame sealing and good installation standards gives stronger value than moving immediately to budget-grade triple units. Poor installation can undermine any glazing specification, so workmanship standards often matter as much as pane count. If condensation and drafts are currently severe, properly installed modern double glazing can feel like a major upgrade even before any further energy measures are added.
Triple glazing is often strongest where noise control and winter comfort are top priorities, or where the home is already highly insulated and the owner wants to optimise every heat-loss pathway. In mixed UK conditions, however, double glazing remains the default recommendation for cost-effective upgrades unless the property has specific performance demands.
Energy Performance and Annual Savings
When homeowners ask whether new windows pay for themselves, the real answer is a combination of hard savings and comfort gains. In typical 3-bedroom homes, upgrading old units to A-rated double glazing can save around £150-£200 per year on heating costs, depending on occupancy, tariff, insulation, and thermostat behaviour. Homes with older single glazing or failing seals usually see the biggest difference.
The financial figure is only part of the value. Better glazing can reduce cold spots near windows, improve room usability in winter, and lower condensation around frames that can otherwise lead to mould and ongoing maintenance. Noise reduction can also be significant near roads, schools, or flight paths. These factors are harder to price in a spreadsheet, but they matter for daily comfort and long-term property condition.
FENSA Certificate and Building Regulations
Replacement windows in England and Wales must comply with building regulations, which cover thermal standards, ventilation, and safety glazing rules. In practical terms, most homeowners meet this requirement by using a FENSA-registered installer who self-certifies the installation and provides a certificate after completion. This document is important and should be stored with your property paperwork.
A missing certificate can create friction during remortgage or sale because buyers and solicitors often ask for proof that replacement windows were compliant. If you do not use a competent person scheme installer, you may need local authority building control approval instead. Either route can be valid, but you must ensure one compliance route is completed and documented. Do not assume an invoice alone is enough evidence.
Before paying a deposit, ask who is responsible for compliance filing, when documentation will be issued, and whether the quote includes any related fees. Serious installers answer this clearly in writing. Ambiguous answers at quote stage are a common warning sign for weak aftercare processes.
Grants and Finance Options
Support routes exist, but eligibility can be narrow. For some low-income households, the ECO4 scheme can contribute toward energy-efficiency measures, including glazing-related improvements where they form part of an eligible package. Eligibility is usually linked to household circumstances, property performance, and supplier or local authority criteria. If grant support matters to your budget, check current rules before you sign with any installer.
Beyond grants, many installers and brokers offer finance. The common options are 0% short-term plans, standard monthly credit with interest, and buy-now-pay-later structures. The lowest monthly payment is not always the cheapest total deal. Compare APR, deposit requirement, settlement terms, and total repayable amount. A slightly higher monthly payment on a shorter term can cost much less overall.
A practical approach is to gather fully itemised cash quotes first, then compare finance against that baseline. If you evaluate finance plans before finalising scope, it is easier for unnecessary upgrades to be bundled into a longer repayment period. Keep your specification fixed, then compare payment structures on the same project value.
How to Compare Quotes Without Overpaying
Good quote comparison is mostly about control of scope. Ask each installer to price the same window schedule, frame material, glazing spec, and finishing assumptions. If one quote looks dramatically cheaper, check whether it excludes disposal, trim work, trickle vents, or compliance handling. A low initial figure that grows with add-ons is common in this market.
Ask for clear warranty details on frames, sealed units, and hardware separately. Also ask who performs aftercare and how quickly faults are handled. Long product warranties are less useful if service response is weak. Confirm payment stages and avoid front-loading too much deposit before survey confirmation.
Finally, verify that your chosen installer can provide building regulations compliance and a FENSA certificate where applicable. In real projects, strong admin and documentation standards are often as valuable as the technical window specification itself.
Double Glazing Cost Calculator (UK 2026)
Use the calculator below to estimate your project value. Enter the number of each window type and select frame and glazing options. The tool returns a realistic low-to-high budget range including optional installation allowances and example finance costs.
This calculator is for planning and quote comparison only. Final pricing depends on survey measurements, site access, product brand, and installer scope. Use it to set budget expectations before requesting formal proposals.
Frequently Asked Questions
1. How much does double glazing cost per window in 2026?
Typical fitted prices are casement £300-£600, bay £800-£1500, sash £600-£1200, and tilt and turn £400-£700. These are realistic UK planning ranges rather than guaranteed fixed prices. Survey outcomes, opening size, frame material, and access can move your final number. The best way to use these figures is as a benchmark when reading itemised quotes from multiple installers.
2. What should I budget for a 3-bedroom house?
For 6-8 windows in a standard 3-bedroom UK house, a common installed range is £3000-£7000. Projects with mixed bay and sash styles, premium materials, or triple glazing may rise above that range and can approach £10,000. The key is to compare complete scopes, not headline totals, because exclusions such as disposal, finishing, or scaffold can distort quote comparisons.
3. Which frame material is best for value?
uPVC is usually best for pure value because upfront cost is lower and maintenance is simple. Aluminium costs more but offers slim profiles and strong modern aesthetics. Timber is often the premium route and can look excellent on traditional homes, but maintenance requirements are higher over time. If budget control matters most, uPVC usually wins; if appearance is the priority, aluminium or timber may justify the extra spend.
4. Is triple glazing worth paying extra for?
Triple glazing can improve comfort and reduce heat loss further, but it usually costs noticeably more than double glazing. In many UK homes, high-quality A-rated double glazing provides better cost-to-benefit value, especially where walls and roof insulation are still the dominant efficiency gaps. Triple glazing makes the most sense where cold exposure, noise, and long-term occupancy justify a slower payback.
5. Do I legally need a FENSA certificate?
Replacement windows must comply with building regulations. Using a FENSA-registered installer is the usual route and gives you a compliance certificate after completion. If you choose a non-registered installer, you generally need local authority sign-off instead. Keep documentation safely because missing compliance records can create delays and extra legal checks when you remortgage or sell your property.
6. Are grants available for low-income households?
Some households may qualify for support through ECO4, depending on income, benefits status, property efficiency profile, and delivery arrangements in their area. Grant availability is not uniform and can change over time. Always check current eligibility rules before agreeing to a contract, and ask providers to confirm in writing what portion of work is covered versus what remains homeowner funded.
7. Can I pay monthly instead of paying upfront?
Yes. Many installers offer finance options such as 0% promotional terms, buy-now-pay-later structures, or standard credit agreements. Compare APR, term length, deposit, settlement flexibility, and total repayable amount before deciding. A lower monthly figure can still be more expensive overall if the term is long or interest is high. Start with a fixed project scope, then compare finance products on that same total.