Quick answer: in 2026 a standard aluminium casement window typically costs between about £475 and £1,100 fitted, depending on size, system and specification. That is roughly £150 to £300 more per window than UPVC. Replacing every window in a three-bedroom semi with aluminium usually lands somewhere between £8,000 and £14,000. In Kent and Surrey, quotes tend to sit towards the upper end of national averages because of higher labour costs across the South East.
This guide brings together the latest published 2026 price data, explains what pushes a quote up or down, and shows where Inspired Glazing’s own prices sit. We make aluminium windows and doors in our own workshop at Fifield, near Windsor, and fit them across Surrey, west Kent and north West Sussex.
Aluminium window prices in 2026: what the data says
Published averages vary a lot, so it helps to see several sources side by side. All the figures below are for supply and installation unless stated.
| Source (2026) | Typical aluminium window price |
|---|---|
| Checkatrade | £350 to £600, average £475 |
| ExpertSure | £400 to £600 for a standard casement; £800 to £1,200 for larger or complex units |
| Harrington Windows calculator | £600 to £850 (600 × 900 mm) up to £800 to £1,100 (1,200 × 1,200 mm) |
| FMB HomePicks (October 2026) | £700 (600 × 900 mm) to £870 (1,200 × 1,200 mm) for a casement |
| Vitrums | £700 to £1,600 fitted for an aluminium casement |
The gap between the lowest and highest figures is mostly about what is included. Lower averages often reflect smaller windows and basic specifications. Higher figures usually assume thermally broken profiles, powder-coated colours and A-rated glazing, which is what most homeowners in Surrey and Kent end up choosing. Price guides for London suggest quotes there run around 15 to 20% above national averages, and the commuter belt tends to follow a similar pattern.
Our prices at Inspired Glazing
- Aluminium windows from £400. The final price depends on size, opening style, colour and glass.
- Lead time from 10 days after your order is confirmed, because we fabricate in our own workshop rather than waiting on a third-party supplier.
- 10-year guarantee on our installations.
- UPVC windows use the Advance 70 system, for homes where budget is the priority.
Every quote follows a free survey, so the figure you get is for your actual openings rather than a brochure estimate.
Whole-house costs: a three-bedroom semi
A typical three-bedroom semi has between eight and twelve windows. Published 2026 estimates for replacing all of them range widely:
| Source | Aluminium (whole house) | UPVC (whole house) |
|---|---|---|
| Checkatrade | About £12,000 (10 to 12 windows) | About £7,500 |
| Vitrums | £8,000 to £16,000 (8 to 10 windows) | £4,000 to £8,500 |
| Harrington Windows | £7,000 to £10,000 (8 to 10 windows) | £4,000 to £6,000 |
For a South East home with good-quality thermally broken aluminium, £8,000 to £14,000 is a sensible working budget for a three-bed semi. Bay windows, large picture windows and heritage-style glazing bars push it higher.
Premium slimline aluminium: Reynaers SlimLine 68
Our core window range is the Reynaers SlimLine 68. Reynaers designed it to mimic the slender look of steel windows, with Functional, Classic and Ferro design variants. Reynaers lists a thermal performance (Uw) of 1.1 W/m²K and an acoustic rating of 47 dB, and its 68 mm frame depth usually fits within the existing plaster line, which makes it a practical replacement window (Reynaers).
Reynaers does not publish retail prices, and SlimLine 68 sits above standard aluminium casements in price. The best way to get a figure is a survey: we will quote SlimLine 68 alongside Cortizo or Alunet aluminium, and UPVC if you want a comparison.
Aluminium bifold and sliding door prices
| Product | Typical 2026 price range | Source |
|---|---|---|
| Aluminium bifold doors (3 to 5 panels) | £3,000 to £7,500, average £5,000 | Checkatrade |
| Bifold for a 3 m opening | £3,000 to £5,500 | MyBuilder (June 2026) |
| Standard aluminium sliding doors | £1,800 to £4,200, average £3,000 | Checkatrade |
| Slimline aluminium sliding doors | From £5,000 | Checkatrade |
For a 3 to 4 metre opening in the South East, budget roughly £4,500 to £9,000 fitted. Premium lift-and-slide systems such as the Reynaers ConceptPatio 130 sit at the top of the sliding door range. If you are creating a new opening, structural work such as a steel beam or lintel is extra and can add significantly to the total. Not sure which to choose? Read our guide to bifold vs sliding doors, or see our aluminium bifold doors.
UPVC and composite doors for comparison
- UPVC casement windows: £250 to £400 each, average £325 (Checkatrade). Coloured or grey UPVC typically costs 10 to 20% more than white.
- UPVC tilt-and-turn windows: around £490 to £695 fitted depending on size (Checkatrade). Aluminium tilt-and-turn is typically £150 to £300 more per window.
- Composite front doors: £1,100 to £1,400 for a basic door, rising with glazing and premium hardware (Checkatrade). See our composite doors.
What changes the price of aluminium windows?
- Size and opening style. Larger panes, tilt-and-turn and flush casements cost more than a simple side-hung casement. Shaped and arched windows carry a big premium.
- Colour. Anthracite grey and black are often standard. Non-standard RAL colours and dual colour (one colour outside, another inside) usually add a modest amount per window.
- Glass. Triple glazing, acoustic glass for busy roads and solar-control glass all add cost.
- Access. Scaffolding for upper floors, difficult access and parking restrictions affect the labour time.
- Removal and making good. A proper quote should include taking out the old frames, disposal and finishing the reveals.
- New or enlarged openings. Cutting a new opening and fitting a lintel adds several hundred pounds before the window itself.
- Conservation areas and listed buildings. Heritage profiles, glazing bars and planning or listed building consent applications can all add cost. Read our guide: do you need planning permission to replace windows?
VAT and grants on new windows
Replacement windows and doors are charged at the standard 20% VAT rate. The 0% VAT rate on energy-saving materials, which runs until 31 March 2027, covers measures such as insulation, heat pumps and solar panels, but not double glazing (HMRC VAT Notice 708/6).
Grants towards windows are limited. The Warm Homes: Local Grant, run by councils in England until March 2028, can include double or triple glazing, but only for lower-income households in homes rated EPC D to G, and an assessor decides which measures are funded. ECO4, which runs to 31 December 2026, can include glazing only in limited cases. The Great British Insulation Scheme never covered windows. In practice, most owner-occupiers in Kent and Surrey will not qualify for a grant towards replacement aluminium windows.
Is aluminium worth the extra cost?
Aluminium costs more up front, but it gives slimmer frames and more glass, a wide colour range, strong security performance and a long lifespan. Checkatrade notes aluminium can last up to twice as long as UPVC. It suits period homes where sightlines matter, contemporary extensions and large openings. UPVC remains a sensible choice for many post-war and modern homes, rental properties and tight budgets. We fit both, so we can give you an honest comparison for your house.
Prices in your area
For local advice, planning notes and the areas we cover, see our pages for windows and doors in Kent, windows and doors in Surrey and windows and doors in Sussex, or compare aluminium windows in Kent, aluminium windows in Surrey and UPVC windows in Surrey.
Get an exact price
Published averages are a starting point. The only accurate figure comes from measuring your openings. Call 01753 965 005, WhatsApp 07934 152 343, or request a free quote online. Aluminium windows start from £400, lead times start from 10 days and every installation carries a 10-year guarantee.
Market price ranges are taken from the 2026 published guides named above and are a guide only; they vary by specification and property. Last updated October 2026.
More products we install
- Front doors
- Composite doors
- French doors
- Patio doors
- Tilt and turn windows
- Grey and black windows
- Sound reducing windows
- Secondary glazing
- Conservatories
- Orangeries
- Porches
- Garage doors
- Fascias, soffits and guttering
- Blinds
- Plantation shutters
Frequently asked questions
How much does an aluminium window cost in 2026?
Published 2026 guides put a standard aluminium casement window at roughly £350 to £1,600 fitted, with most typical quotes between about £475 and £1,100 depending on size and specification. Homes in Kent and Surrey tend to see quotes towards the upper end. Inspired Glazing's aluminium windows start from £400.
How much more do aluminium windows cost than UPVC?
Aluminium is typically around £150 to £300 more per window than UPVC, or roughly 30 to 60% more overall, according to 2026 price guides from Checkatrade and ExpertSure. In return you get slimmer frames, more glass, a wider colour range and a longer expected lifespan.
How much does it cost to replace all the windows in a three-bed house with aluminium?
Published estimates range from about £7,000 to £16,000 for eight to twelve windows, with Checkatrade putting it at around £12,000. For a South East home with good-quality thermally broken aluminium, £8,000 to £14,000 is a sensible working budget.
How much do aluminium bifold doors cost?
Checkatrade's 2026 guide puts aluminium bifold doors at £3,000 to £7,500, with an average of £5,000. MyBuilder gives £3,000 to £5,500 for a 3 metre opening. Structural work for a new or wider opening is extra.
How much do aluminium sliding doors cost?
Standard aluminium sliding doors average around £3,000 fitted, and slimline aluminium sliding doors start from about £5,000, according to Checkatrade's 2026 guide. Premium lift-and-slide systems such as Reynaers ConceptPatio 130 sit at the top of that range.
Is there VAT on new windows?
Yes. Replacement windows and doors are charged at the standard 20% VAT rate. The temporary 0% VAT rate on energy-saving materials, which runs until 31 March 2027, does not cover double glazing, according to HMRC VAT Notice 708/6.
Can I get a grant for new windows?
Only in limited cases. The Warm Homes: Local Grant can include double or triple glazing for lower-income households in homes rated EPC D to G, and ECO4 can include glazing in limited cases until 31 December 2026. Most owner-occupiers in Kent and Surrey will not qualify.
How long does it take to get aluminium windows?
Industry lead times for bespoke aluminium are commonly a few weeks. Because Inspired Glazing fabricates in its own workshop at Fifield, near Windsor, our lead times start from 10 days after your order is confirmed. Fitting a typical house usually takes one to three days.