Double glazing costs between £350 and £1,400 per window in the UK in 2026, depending on the frame material, window style, and glass specification. A full house of uPVC double glazing for a typical 3-bed semi-detached costs £4,000-£6,000, while aluminium frames push the total to £7,000-£10,000. The biggest cost variables are frame material, window size, and whether you choose a national installer or a local FENSA-registered company. For practical advice on avoiding common mistakes, see our double glazing tips guide.
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We’ve verified these prices against Checkatrade, the Federation of Master Builders (FMB), and multiple installer quotes across the UK. This guide breaks down costs by material, window style, and house size – with verified 2026 pricing and the latest on government grants including the Warm Homes: Local Grant (up to £30,000 for eligible homeowners).
Whether you’re replacing single glazing, upgrading older double-glazed units, or fitting windows in a new extension, you’ll find the exact figures you need to budget accurately.
- uPVC casement windows - the most popular choice, costing £350-£600 per window installed
- Full house costs - expect £4,000-£6,000 for a 3-bed semi in uPVC, or £10,000-£16,000 in timber
- Energy savings - A-rated double glazing saves up to £175/year on heating bills (Energy Saving Trust)
- 0% VAT until March 2027 - double glazing qualifies as an energy-saving material, saving you up to £1,000 on a £5,000 job
- Government grants available - the Warm Homes: Local Grant offers up to £30,000 for eligible homeowners in England
How Much Does Double Glazing Cost Per Window?
A single double-glazed window costs between £350 and £1,400 installed in 2026, with the price driven primarily by your choice of frame material. uPVC is the most affordable option at £350-£600 per window, while timber frames cost roughly double at £950-£1,400.
These prices include both supply and professional installation by a FENSA or CERTASS registered installer. All figures assume standard sizes (around 1200mm x 1200mm for a casement window). Larger windows, non-standard shapes, and ground-floor vs upper-floor access will all affect the final price.
| Frame Material | Cost Per Window | Typical Cost | Premium vs uPVC | Best For |
|---|---|---|---|---|
| uPVC Casement | £350-£600 | £450-£500 | – | Best value, low maintenance |
| uPVC Sash | £700-£1,500 | £900-£1,100 | +60-80% | Period properties, traditional look |
| Aluminium | £600-£850 | £700-£750 | +25% | Modern aesthetics, slim frames |
| Timber | £950-£1,400 | £1,100-£1,200 | +50% | Heritage properties, natural look |
| uPVC Sliding | £600-£1,400 | £800-£1,000 | +40-60% | Limited external space |
Prices sourced from Checkatrade, FMB, and Valuedoors as of February 2026. All costs include VAT at the current 0% rate for energy-saving materials.
Double Glazing Cost by Material
Frame material is the single biggest factor in double glazing cost, creating a price difference of up to 50% between the cheapest and most expensive options. uPVC dominates the UK market for good reason – it offers the best balance of cost, durability, and thermal performance.
uPVC Double Glazing
uPVC casement windows cost £350-£600 per window installed, making them the most affordable double glazing option in the UK. They require virtually no maintenance beyond occasional cleaning, won’t rot or warp, and typically achieve A-rated energy performance as standard. Most UK homes – over 93% – now have some form of double glazing, and the vast majority use uPVC frames.
The main drawback is aesthetics. uPVC frames are thicker than aluminium, and while woodgrain-effect finishes are available, they don’t match the look of real timber. For modern builds or period properties where slim sightlines matter, aluminium or timber may be worth the premium.
Aluminium Double Glazing
Aluminium frames cost £600-£850 per window – roughly 25% more than equivalent uPVC. The premium buys you slimmer frames (maximising glass area and light), a contemporary aesthetic, and exceptional durability. Aluminium won’t discolour over time and is fully recyclable at end of life.
Modern aluminium frames use a thermal break design to prevent heat transfer through the metal, so they now match uPVC on energy ratings. They’re particularly popular for bifold doors and large-format windows where structural strength is needed.
Timber Double Glazing
Timber windows are the premium option at £950-£1,400 per window – approximately 50% more than uPVC. They offer the best thermal insulation of any frame material, a natural aesthetic that suits period and heritage properties, and can be repaired rather than replaced if damaged.
The trade-off is maintenance. Timber frames need repainting or re-staining every 3-5 years to prevent rot, and they’re more susceptible to warping in wet conditions. Some manufacturers offer engineered timber or timber-aluminium composite frames that reduce maintenance requirements, but these push prices even higher.
Cost by Window Style
Window style affects both the per-unit price and the complexity of installation. Standard casement windows are the cheapest to install, while sash, bay, and tilt-and-turn styles carry significant premiums due to their more complex mechanisms and larger frame sizes.
| Window Style | uPVC Cost | Aluminium Cost | Notes |
|---|---|---|---|
| Casement | £350-£600 | £600-£850 | Most common, side or top-hung |
| Sash (sliding) | £700-£1,500 | £1,000-£1,800 | Period properties, counterbalanced |
| Tilt-and-turn | £450-£700 | £700-£950 | Versatile ventilation, easy cleaning |
| Bay window (3 panels) | £1,200-£2,500 | £1,800-£3,500 | Structural support may be needed |
| Fixed (non-opening) | £200-£400 | £350-£550 | Cheapest – no moving parts |
Bay windows deserve special attention because the cost isn’t just the glass and frames. If the existing bay structure needs reinforcement or the roof above needs work, structural costs of £500-£1,500 may be added on top. Always get a survey before committing to a bay window replacement quote.
Sash windows are the next most expensive style due to their sliding mechanism and counterbalance system. uPVC sash windows that replicate the look of traditional timber sashes cost £700-£1,500 per window – a significant premium over casement, but far cheaper than authentic timber sash replacements at £1,500-£3,000+. For period properties in conservation areas, you may be required to install timber sash windows to match the existing street character, which can double or treble the cost of a standard uPVC project.
Tilt-and-turn windows cost £450-£700 in uPVC and are increasingly popular in the UK, particularly for upper-floor windows. They tilt inward from the top for ventilation and turn fully inward for cleaning – a practical advantage for windows above ground level where external access is difficult.
Double Glazing Cost by House Size
The total cost of double glazing a whole house depends primarily on the number of windows, which varies by property type. A 2-bed terraced house might have 6-8 windows, while a 4-bed detached could have 12-15 or more.
| Property Type | Typical Windows | uPVC Cost | Aluminium Cost | Timber Cost |
|---|---|---|---|---|
| 2-bed terraced | 6-8 | £2,500-£4,000 | £4,200-£6,000 | £6,000-£9,000 |
| 3-bed semi-detached | 8-10 | £4,000-£6,000 | £7,000-£10,000 | £10,000-£16,000 |
| 3-bed detached | 10-12 | £5,000-£7,500 | £8,000-£12,000 | £12,000-£18,000 |
| 4-bed detached | 12-15 | £6,500-£9,500 | £10,000-£15,000 | £15,000-£22,000 |
These figures assume standard casement windows throughout. If your property has sash windows, bay windows, or a mix of styles, expect to pay 20-40% more than the figures above. Premium installations with triple glazing, composite frames, or specialist heritage windows can reach £20,000+ even for a 3-bed house.
Cost of Double Glazing a 3-Bed House
A 3-bed semi-detached house is the most common property type in the UK and typically has 8-10 windows. In uPVC, you’re looking at £4,000-£6,000 for the full house – that’s based on a mix of casement windows in bedrooms and living areas, plus potentially a larger picture window or bay downstairs. The upper end of the range applies to semi-detached homes with more window openings on the exposed side, or those with larger-than-average windows.
For a 3-bed detached house, add 2-4 extra windows (more exposed wall space) and budget £5,000-£7,500 in uPVC. Detached properties often have more complex window configurations – feature windows above the front door, side-panel windows next to external doors, and potentially en-suite bathroom windows that terraced and semi-detached homes lack.
Cost for a 2-Bed or 4-Bed House
A 2-bed terraced house with 6-8 windows typically costs £2,500-£4,000 for full uPVC double glazing – often the most cost-effective whole-house project because fewer windows means lower scaffolding costs and a quicker installation (usually 1-2 days). For a 4-bed detached house with 12-15 windows, budget £6,500-£9,500 in uPVC. Larger homes usually require 3-4 days of installation and may need scaffolding on multiple elevations, adding £600-£1,200 to the bill.
If you’re on a tight budget, consider replacing the most heat-inefficient windows first – typically single-glazed windows facing north or those in living areas where you spend the most time. You can phase the project over 2-3 years to spread the cost.
What Affects Double Glazing Costs?
Beyond material and style, several other factors can add 10-30% to your double glazing quote. Understanding these variables helps you compare quotes accurately and avoid unexpected costs on installation day.
Glass Specification
Standard double glazing uses two panes with an air-filled cavity, but upgrading to argon gas filling adds just £30-£40 per window while reducing heat loss by up to 31%. Argon-filled units achieve U-values as low as 1.1, compared to approximately 1.6 for standard air-filled units. When paired with Low-E (low emissivity) glass, total heat loss reduction can exceed 30% versus standard double glazing.
Most reputable UK manufacturers now include argon gas as standard in A-rated windows. If your quote specifies air-filled units, it’s worth querying – the 5-10% premium for argon is minimal relative to the overall window cost and delivers measurable energy savings over the 25-year lifespan of the windows.
Installation Complexity
Labour costs account for around 30-40% of the total price and vary significantly based on access, structural work, and the condition of existing frames. Ground-floor windows are cheaper to install than upper floors (no scaffolding needed). Listed buildings or conservation areas may require planning permission and specialist installers, adding 15-25% to the quote.
National vs Local Installer
National companies like Anglian and Everest typically charge 15-30% more than local FENSA-registered installers for equivalent products. The premium covers marketing overheads, branded products, and extended warranty schemes. Local installers using the same glass and hardware from manufacturers like Yale, Pilkington, or Deceuninck can offer identical performance at a lower price.
That said, national installers offer benefits that some homeowners value: dedicated aftercare teams, insurance-backed guarantees, and the peace of mind that comes with a larger company. See our best window companies guide for a detailed comparison.
Regional Price Variation
Double glazing costs vary by 10-20% across the UK. London and the South East are the most expensive regions due to higher labour costs and property values. Scotland, the North East, and Northern Ireland tend to be 10-15% cheaper than the national average. For a 3-bed semi in London, expect to pay £5,000-£7,000 in uPVC compared to £3,500-£5,000 in the North East or Scotland for the same specification.
Energy Rating
Windows are rated from A++ (best) to E (worst) under the BFRC Window Energy Rating scheme. Since 2022, Building Regulations require a minimum energy rating of C (U-value of 1.4 W/m2K) for replacement windows. Most mainstream manufacturers now offer A-rated windows as standard, with the price difference between C-rated and A-rated units being relatively small – typically £20-£40 per window.
Upgrading to A+ or A++ rated windows adds £40-£80 per window but delivers marginally better thermal performance. Unless you’re in a very exposed location or replacing a large number of windows, the incremental savings rarely justify the premium. A-rated with argon gas filling is the sweet spot for most UK homes.
Number of Opening Sections
A window with two opening sections (both sides of a casement pair) costs more than a single opener with a fixed pane alongside. Each opening mechanism adds hinges, locks, handles, and weather seals – typically adding £40-£80 per opening section. Where ventilation needs allow, specifying some windows as fixed-pane or single-opener can reduce costs without sacrificing thermal performance.
Labour and Installation Costs
Installation labour typically costs £100-£150 per window for standard casement replacements, with a full day’s work covering 4-6 windows. Most installers charge a day rate of £250-£350 per fitter, and you’ll typically need two fitters working together for safety and efficiency.
| Installation Element | Typical Cost | Notes |
|---|---|---|
| Labour per window | £100-£150 | Standard casement replacement |
| Scaffolding | £300-£800 | Upper floors, per elevation |
| Skip hire | £200-£350 | For old window disposal |
| Making good (plastering) | £50-£100/window | Internal reveals after fitting |
| FENSA certificate | Included | If using FENSA-registered installer |
| Building control (non-FENSA) | £200-£400 | Required if installer not registered |
Always confirm whether the quote is “supply and fit” or “supply only.” Supply-only prices are typically 40-50% lower, but you’ll need to arrange a separate installer and will be responsible for ensuring Building Regulations compliance yourself.
Always use a FENSA or CERTASS registered installer. They self-certify that the work complies with Building Regulations, which means you avoid the cost (£200-£400) and hassle of a separate local authority inspection. If you sell the property later, a missing compliance certificate can cost approximately £700 to obtain retrospectively.
Additional Costs to Budget For
The window quote itself is rarely the full cost. Several additional expenses can add 15-25% to your total budget, and many homeowners are caught out by costs that weren’t mentioned in the initial quote.
Sills and trims: If your existing window sills are damaged or the wrong size, replacements cost £30-£60 per sill in uPVC. Internal trims and capping can add another £20-£40 per window.
Lintels: Older properties (pre-1980s) may have inadequate lintels above the window opening. Replacing a lintel costs £300-£600 per window and is only discovered once the old frame is removed. A pre-installation survey should identify this.
Redecorating: Budget £50-£100 per window for making good and redecorating the internal reveals after installation. Some installers include basic plastering in the quote, but painting is almost always your responsibility.
Disposal of old windows: Most installers include removal and disposal in their quote, but some charge separately – typically £20-£40 per window or a flat £200-£350 for skip hire on a whole-house job. If your old windows contain lead paint (common in properties built before 1960), specialist disposal may be required at additional cost.
Doors: If you’re replacing all windows, it makes sense to replace external doors at the same time for consistent aesthetics and energy performance. A uPVC front door costs £800-£1,200 installed, while composite front doors cost £900-£1,800. Patio doors range from £1,200-£3,000 depending on type and size. French doors cost £1,000-£2,500 depending on material, offering a classic alternative to sliding patio doors. Bifold doors are the premium option at £2,000-£5,000 for a standard 3-panel configuration, but add dramatic light and space to living areas.
Secondary glazing: If your property is listed or in a conservation area where replacement double glazing isn’t permitted, secondary glazing (fitting a second pane inside the existing window) costs £100-£300 per window. It’s less effective than full double glazing but significantly cheaper and doesn’t require planning permission.
Energy Savings from Double Glazing
Replacing single glazing with A-rated double glazing saves up to £175 per year on heating bills for a detached house, according to the Energy Saving Trust. For a semi-detached house, the saving is around £140 per year, while a mid-terrace saves approximately £60 per year.
Over the typical 25-year lifespan of double-glazed windows, a semi-detached homeowner replacing single glazing would save a total of approximately £4,875 – 35% more than the £3,600 installation cost. That represents a genuine return on investment, not just a comfort improvement.
| Property Type | Annual Saving | CO2 Reduction | 25-Year Total Saving |
|---|---|---|---|
| Detached (A++ rated) | Up to £175 | ~500 kg/year | ~£4,375 |
| Semi-detached (A rated) | £140 | 380 kg/year | £4,875* |
| Mid-terrace (A rated) | £60 | ~160 kg/year | ~£1,500 |
*Based on Energy Saving Trust figures, assuming replacement of single glazing. Savings are significantly lower when replacing older double glazing with newer units, and depend on your heating system, insulation levels, and energy usage patterns. Energy-efficient windows with argon gas and Low-E coatings will deliver savings at the higher end of these ranges.
Beyond heating bills, double glazing reduces your property’s carbon footprint. A semi-detached home with A-rated double glazing saves approximately 380 kg of CO2 per year compared to single glazing. With the UK’s net zero targets driving policy, improved energy efficiency also protects your EPC rating – which increasingly affects both property value and access to government grants.
It’s worth noting that if you’re replacing double glazing that’s already 15-20 years old (rather than single glazing), the annual saving drops to approximately £20-£50 per year. The upgrade from C-rated to A-rated glazing is worthwhile for comfort and noise reduction, but the financial payback is much longer. In that scenario, ensuring your loft and cavity wall insulation are up to standard will typically deliver a better return per pound spent.
Does Double Glazing Add Value to Your Home?
Double glazing typically adds 5-10% to a UK home’s resale value, with the biggest gains for properties currently on single glazing or with units more than 20 years old. On a £300,000 property, that’s £15,000-£30,000 in value uplift against a £4,000-£6,000 install cost – one of the highest-return home improvements available.
The value impact comes from three signals buyers and surveyors look for:
- EPC rating uplift: Modern A-rated double glazing typically lifts an EPC by 5-10 points, moving many homes from D to C – increasingly important as mortgage lenders and renters factor EPC into decisions
- Reduced future maintenance signal: Buyers know they won’t need to budget £4-6k for replacement in the next 5 years
- Comfort and noise reduction: Estate agents report DG-equipped homes show better in viewings, particularly on busy roads
The value-add is largest when replacing failing single glazing in a period property. The smallest return is upgrading from already-functional 10-year-old DG to triple glazing, where the resale uplift rarely covers the upgrade cost.
Double Glazing Grants and Financial Help
Several government schemes can reduce or eliminate the cost of double glazing for eligible homeowners. The most significant is the Warm Homes: Local Grant, which launched in April 2025 with £500 million of funding and explicitly covers double and triple glazing for homes in England.
| Scheme | Status | Location | Max Grant | Covers DG? |
|---|---|---|---|---|
| Warm Homes: Local Grant | ACTIVE (to March 2028) | England | Up to £30,000 | Yes |
| Nest Scheme | Active | Wales | Varies | Sometimes |
| Home Energy Scotland | Active | Scotland | £8,000 loan | Loan only |
| Affordable Warmth | Active | Northern Ireland | £7,500 | Yes |
| ECO4 | CLOSED March 2026 | UK-wide | – | No longer available |
The Warm Homes: Local Grant is the most generous scheme currently available. To qualify, you need a household income of £36,000 or below (or receive a means-tested benefit), an EPC rating of D to G, and must be a private homeowner or renter in England. No household contribution is required – the grant covers the full cost. Apply at gov.uk/apply-warm-homes-local-grant.
Home Energy Scotland offers interest-free loans of up to £8,000 for double glazing – but only for upgrading single glazing to double or triple. It is not a grant, and it does not cover replacing existing double glazing. Many competitor guides get this wrong. For full details on all available schemes, see our double glazing grants guide.
0% VAT on Double Glazing
Since April 2022, double glazing has qualified for 0% VAT as an energy-saving material when installed in residential properties. This rate applies until March 2027, after which it reverts to 5%. On a typical £5,000 installation, the 0% rate saves you £250 compared to the old 5% rate, or £1,000 compared to the standard 20% VAT rate. Your installer should apply this automatically – if they charge VAT on double glazing, query it.
Double Glazing vs Triple Glazing
Triple glazing costs 20-40% more than double glazing, with a typical uPVC triple-glazed casement window costing £500-£800 installed. The additional pane delivers better thermal performance (U-values of 0.8-1.0 vs 1.1-1.6 for double), improved sound insulation, and slightly better security.
However, the energy savings from triple over double glazing are modest – typically £20-£40 per year for a whole house. Given the 20-40% price premium, the payback period is 20+ years, making it harder to justify on pure ROI grounds. Triple glazing makes the most sense for new builds (where the marginal cost is smaller), very exposed properties, or rooms where noise reduction is a priority.
For most UK homeowners replacing single or old double glazing, A-rated double glazing with argon gas and Low-E coatings represents the best balance of performance and value.
| Feature | Double Glazing (A-rated) | Triple Glazing |
|---|---|---|
| Typical U-value | 1.1-1.4 | 0.8-1.0 |
| Cost per window (uPVC) | £350-£600 | £500-£800 |
| Price premium | – | 20-40% more |
| Weight | Standard | 30-50% heavier |
| Sound insulation | Good | Excellent |
| Best for | Most UK homes | New builds, exposed sites, noise hotspots |
Replace Panes vs Full Window Replacement
If your double glazing has failed – condensation between the panes, blown seals, or draughts around the edges – you don’t necessarily need to replace the entire window. Sealed unit replacement (replacing just the glass unit within the existing frame) costs £70-£150 per window, compared to £350-£600+ for a full window replacement.
Sealed unit replacement makes sense when the frames are still in good condition (no warping, cracking, or discolouration) and the issue is purely with the glass unit. It’s a particularly cost-effective option for homes with relatively modern uPVC frames (10-15 years old) where the seals have failed but the frames have another 10-15 years of life.
Full replacement is the better choice when frames are damaged, the window style needs updating, or you want to upgrade from old C/D-rated units to modern A-rated performance. Replacing just the glass won’t improve the frame’s thermal performance, and older frames may not accept modern high-performance glazing units.
| Option | Cost Per Window | When to Choose | Lifespan |
|---|---|---|---|
| Sealed unit only | £70-£150 | Blown seals, frames still sound | 10-15 years |
| Full replacement | £350-£600+ | Damaged frames, upgrading spec | 20-25 years |
| Secondary glazing | £100-£300 | Listed buildings, conservation areas | 15-20 years |
A useful rule of thumb: if more than half of your windows need sealed unit replacements, it’s often more cost-effective to replace all windows at once. Bulk orders typically attract a 10-15% discount per window, and you avoid the hassle and cost of organising separate installations. You’ll also get a consistent finish across the whole house and a single warranty covering everything.
Is It Cheaper to Replace All Windows at Once?
Replacing all windows in one project is usually 15-25% cheaper per window than doing them in stages. UK installers offer bulk discounts on labour, scaffolding is set up once, and material orders are consolidated – typically saving £75-£150 per window on a 6-window install.
The maths for a typical 3-bed semi (8 windows):
- All 8 windows together: £3,200-£4,800 total (£400-£600 per window installed)
- Doing 4 windows now, 4 next year: £3,800-£5,600 total (£475-£700 per window) – roughly £600-£800 more overall
- One window at a time: £4,800-£7,200 total – 50%+ price premium for callout fees and minimum-order surcharges
The exception is when budget genuinely can’t stretch. In that case, prioritise the worst-affected rooms first (north-facing rooms, rooms with the most draught complaints, or rooms used most often). Most installers offer 0% finance over 12-24 months, which often makes a single-project install affordable even when paying upfront isn’t.
Signs You Need New Windows
Not every window problem requires full replacement. Understanding which issues are repairable and which indicate end-of-life helps you avoid spending thousands unnecessarily – or delaying a replacement that’s costing you money in wasted energy. Our guide to double glazing repairs covers what each fault type costs to fix.
Condensation between panes means the sealed unit has failed. The gas fill has leaked out and moisture has entered. This can’t be repaired – the sealed unit needs replacing (£70-£150) or the whole window if frames are also deteriorating.
Draughts around the edges may indicate failed seals, which can sometimes be replaced for £20-£40 per window. If the frame itself has warped or the hinges have worn, replacement is likely the better long-term option.
Difficulty opening or closing often signals worn hinges (£30-£50 to replace) or warped frames. If the window mechanism is failing on multiple windows of the same age, it usually makes more sense to budget for phased replacement rather than ongoing repairs.
Visible rot on timber frames means replacement is needed. uPVC frames that have discoloured heavily or become brittle (typically after 20+ years) also indicate end of life.
Is It Worth Replacing 20-25-Year-Old Double Glazing?
Double glazed windows installed before 2005 are typically worth replacing if you notice condensation between the panes, draughts, or rising heating bills. Modern A-rated units are 30-40% more energy-efficient than 20-year-old equivalents and pay back the £350-£600 per-window cost within 8-12 years through lower energy bills.
Watch for these specific signs your existing units have failed:
- Misted or fogged glass – the seal between panes has broken; the unit no longer insulates
- Condensation on the inside surface in winter – inner pane is too cold, indicating a thermally inefficient unit
- Draughts you can feel with a hand close to the window edge – frame seals or hinges have degraded
- Difficulty opening or locking – frames warped or hardware corroded, often a sign full replacement is overdue
- Visible damage to the frame – cracks in uPVC, rot in timber, or oxidation pitting on aluminium
If only the sealed unit (the glass) has failed but the frame is intact, you can replace just the unit for £100-£200 – far cheaper than a full window. See our Replace Panes vs Full Window Replacement section above for the decision framework.
How to Get the Best Price on Double Glazing
The single most effective way to reduce your double glazing costs is to get at least three quotes from different installers. Prices for the same specification can vary by 30-50% between companies, particularly between national brands and local FENSA-registered firms.
Get multiple quotes: Always compare at least 3 quotes for the same specification. Ensure each quote specifies the frame material, glass type (including gas fill), energy rating, and whether scaffolding and making good are included.
Avoid high-pressure sales: National installers often use home visits with “today only” discounts. These initial quotes are typically inflated by 30-50% to leave room for negotiation. Never sign on the day – legitimate discounts will still be available next week.
Time your purchase: Installers are quietest in late autumn and winter (October-February). Booking during off-peak periods can save 10-15% as companies are more willing to negotiate to fill their schedules.
Consider phasing: If budget is tight, replace the worst-performing windows first (single-glazed, north-facing, or those in the rooms you use most) and do the rest in a second phase. Some installers offer better per-window rates on larger orders.
Check for grants first: Before committing to a quote, check your eligibility for the Warm Homes: Local Grant or devolved nation schemes. A successful application could cover the entire cost.
Bundle doors with windows: If you need new doors too, ordering them alongside your windows from the same installer typically saves 5-10% compared to separate orders. Matching frames, colours, and hardware also gives a more cohesive finish.
Negotiate on larger orders: Installers expect to negotiate on whole-house jobs. Once you have 3 quotes, use the lowest as leverage. A common approach: tell your preferred installer what the cheapest quote is and ask if they can match it. Many will come within 5-10% to win the business, especially during quieter months.
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How to Choose a Window Installer
Choosing the right installer is as important as choosing the right windows. A poorly fitted window will underperform regardless of specification, and using an unregistered installer creates compliance headaches when you come to sell.
Check registration: Insist on a FENSA or CERTASS registered installer. Over 13 million FENSA certificates have been issued since 2002, covering 50% of all UK homes. Registration means the installer self-certifies Building Regulations compliance, saving you the cost and hassle of a local authority inspection.
Verify insurance: Ask for proof of public liability insurance (minimum £2 million) and employer’s liability insurance. Any reputable installer will provide this without hesitation.
Check guarantees: Look for a minimum 10-year guarantee on frames and sealed units, insurance-backed by a scheme like the GGF Deposit Protection and Performance Guarantee, or similar. An insurance-backed guarantee protects you if the company ceases trading.
Read reviews carefully: Check Checkatrade, Trustpilot, and Google Reviews. Pay attention to recent reviews (last 12 months) and look for patterns in complaints – recurring issues with after-sales service or finishing quality are red flags.
For detailed comparisons of the UK’s main installers, see our guide to the best window companies in the UK.
Get a written quote: Verbal estimates are meaningless. Insist on a detailed written quote that itemises: window units (frame material, glass specification, energy rating), installation labour, scaffolding, disposal of old windows, making good, and any extras like new sills or lintels. This makes comparison between installers straightforward and protects you from unexpected add-ons after work begins.
Survey before committing: Any reputable installer will offer a free home survey before providing a final quote. During the survey, they should check the condition of existing frames, measure each opening individually (standard sizes rarely apply to older properties), assess access requirements, and identify any structural work needed. Be wary of any installer who quotes without visiting your property.
Maintenance Costs
Ongoing maintenance costs depend almost entirely on your frame material. uPVC is the cheapest to maintain by a significant margin, while timber requires regular investment to preserve its appearance and structural integrity.
| Material | Annual Maintenance | Tasks Required | Lifespan |
|---|---|---|---|
| uPVC | £0-£20 | Occasional cleaning, lubricate hinges | 20-25 years |
| Aluminium | £0-£30 | Clean frames, check seals annually | 25-30+ years |
| Timber | £100-£300 | Repaint/restain every 3-5 years, check for rot | 30-60 years (with maintenance) |
Timber frames have the longest potential lifespan (60+ years with diligent maintenance) but the highest maintenance cost. When factoring total cost of ownership over 25 years, uPVC remains the most economical choice: £4,500 upfront with virtually zero maintenance, versus £12,000 upfront plus £2,500-£7,500 in maintenance for timber.
Year-on-Year Price Trends
Double glazing prices increased by approximately 8-12% between 2022 and 2024, driven by post-pandemic supply chain disruption, higher energy costs in manufacturing, and raw material inflation. Glass and aluminium were particularly affected, with some installers reporting 15-20% increases in aluminium frame costs.
Prices have stabilised in 2025-2026, with most installers holding or making only modest increases (2-4%) as supply chains normalised. The UK glazing industry is valued at £1.7 billion (IBISWorld 2025) with a projected growth rate of 5.3% to 2030, driven largely by the retrofit market – which outpaces new builds 3:1 due to rising energy costs and government energy efficiency targets.
Looking ahead, the GGF and British Glass estimate that 80 million windows across UK homes need replacement to meet net zero targets, with 98% of current windows falling short of current Building Regulations. This demand is likely to support prices at current levels or slightly above, particularly for higher-specification products.
The 0% VAT rate on energy-saving materials (including double glazing) is scheduled to end in March 2027, reverting to 5%. If you’re planning to replace windows in the next 12 months, completing the work before the VAT rate changes will save you £250 on a typical £5,000 job. There’s no guarantee the 0% rate will be extended, so timing your project to fall within the current window could be worthwhile.
The UK residential glazing market is dominated by retrofits, which outpace new builds 3:1 according to industry data. With 1.9 million residential window installations carried out in 2024, supply is strong across the UK, which keeps pricing competitive. The glazing industry supports approximately 2,990 businesses, so most areas have multiple local installers competing on price and service.
Is Double Glazing Worth the Cost?
Double glazing is worth the investment for most UK homeowners, particularly those still living with single glazing or double-glazed units more than 15-20 years old. The combination of energy savings, increased comfort, reduced noise, improved security, and added property value makes it one of the most reliable home improvements.
For a semi-detached house replacing single glazing with A-rated uPVC double glazing at a cost of around £4,000-£5,000, the energy savings alone (£140/year) deliver a payback period of approximately 30-35 years. That’s longer than the window lifespan – but energy savings aren’t the only return. Estate agents consistently report that new double glazing adds 5-10% to property value, and the improved EPC rating can make the difference between a sale and a stall.
Where double glazing offers less clear value is replacing relatively modern double-glazed units (installed in the last 10-15 years) that are still performing well. Unless the seals have failed or the frames are damaged, the incremental energy saving from upgrading C-rated to A-rated glazing is modest – typically £30-£50 per year for a whole house. In that case, investing in loft or wall insulation will deliver a better return per pound spent.
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How We Researched These Prices
Prices in this guide were compiled from installer quotes gathered across 8 UK regions, manufacturer price lists, and cross-referenced against Checkatrade, the Federation of Master Builders (FMB), Energy Saving Trust, GreenMatch, and industry data from IBISWorld and the Glass and Glazing Federation (GGF). We obtained quotes from both national installers (Anglian, Everest, Safestyle) and independent FENSA-registered companies to ensure our ranges reflect the full market. All costs include supply, professional installation, and 0% VAT on energy-saving materials. Prices were last verified in February 2026 and are updated quarterly.
