| What you are replacing | uPVC | Aluminium |
|---|---|---|
| Single window, supplied & fitted | from £500 | from £950 |
| Full house (8–10 windows) | £5,500–£12,000 | £11,000–£20,000 |
| Sliding sash window | from £900 | — |
| Bay or bow window | £2,500–£4,500 | £3,500–£6,000 |
| Composite front door | from £1,400 | |
Get your fixed price. Book a free survey and we will give you a written, itemised quote — usually within 24 hours of the visit. Call 01753 965 005 or request a callback. 0% and low-rate finance is available on larger projects, subject to status.
Prices in your area: Berkshire, Windsor, Maidenhead, Slough and Bracknell.
The rest of this guide explains what drives the price — material, style, glazing and access — and how to tell a proper quote from a cheap one. Replacing windows is a long-term investment in thermal performance, security and how the house looks and feels.
At Inspired Glazing, we prioritize transparency. This guide provides a comprehensive breakdown of the current costs associated with window installations in 2026, comparing materials like uPVC windows and aluminium windows, and detailing how geographic factors influence your final quote.
What actually drives the price of new windows
Two houses on the same street can get very different quotes. The price of a window replacement is driven by five things, roughly in order of impact:
- Material and system — uPVC is the most cost-effective; aluminium costs more but gives slimmer frames and a longer life. Timber and heritage systems cost the most.
- Number and size of windows — the per-window price falls as the job gets bigger, so a whole-house replacement is better value than doing one or two at a time.
- Glass specification — standard double glazing, high-performance low-E, acoustic, toughened or triple glazing all change the price.
- Style and opening type — fixed and casement windows are cheapest; sash, bay, bow and shaped windows cost more to make and fit.
- Access and property type — upper floors, scaffolding, conservation-area or listed-building requirements and difficult access all add cost.
Where you are in the country matters too. Prices in London and the South East run roughly 10–20% above the national average; the North and parts of the Midlands sit below it. We’re based in Fifield near Windsor and work across Berkshire and the Thames Valley, so the figures on this page reflect real quotes in that area.
Average Replacement Windows Cost in 2026
As of April 2026, the average cost for a single replacement window typically ranges between £500 and £1,500. This figure includes the window unit, professional installation, and VAT.
For a standard three-bedroom semi-detached home in Berkshire or the wider Thames Valley, a full house replacement (approx. 8–10 windows) generally ranges from £5,500 to £11,000 for uPVC, and £10,000 to £18,000 for high-specification aluminium systems.
Material Showdown: uPVC vs. Aluminium
Choosing the right material is the most significant factor affecting your budget. Both uPVC and aluminium windows offer excellent energy-rated windows performance in 2026, but they serve different architectural and budgetary needs.
1. uPVC Windows: Efficiency and Value
uPVC windows and doors remain the most popular choice for homeowners due to their exceptional thermal insulation and cost-effectiveness.
- Average Cost: £500 – £850 per window.
- Performance: Modern multi-chambered profiles provide U-values as low as 1.0 W/m²K, exceeding current building regulations.
- Maintenance: Virtually zero maintenance beyond occasional cleaning.
- Design: While traditionally white, 2026 trends see a high demand for “Anthracite Grey” and “Black” woodgrain foils that mimic the look of aluminium at a lower price point.
2. Aluminium Windows: The Architectural Standard
For modern extensions and high-end renovations, aluminium windows are the industry standard. Their structural integrity allows for slim sightlines and larger glass spans.
- Average Cost: £950 – £1,550 per window.
- Durability: Aluminium does not warp, rot, or rust, making it a “fit and forget” solution for decades.
- Aesthetics: Ideal for Ascot and Sunningdale properties where floor-to-ceiling glass and minimalist frames are preferred.
- Security: Naturally robust frames paired with multi-point locking systems offer superior resistance to forced entry.
Style Variations: Impact on Budget
The opening mechanism and aesthetic style of your window will dictate the complexity of the manufacturing process.
Casement Windows
The most common style in the UK. These are hinged at the side or top. They are generally the most affordable because the hardware is straightforward.
- Budget Impact: Lowest.
Sash Windows
Essential for heritage properties in Windsor, Eton and nearby conservation areas. Sash windows use a vertical sliding mechanism. Due to the weights or spring balances required, they are more expensive to produce and install.
- Budget Impact: High. Expect to pay a 30–50% premium over casement styles.
Bay and Bow Windows
These involve multiple window units joined at angles. They require structural support and specialized “bay poles.”
- Budget Impact: Very High. A single large bay window installation can cost between £2,500 and £4,500.
Technical Factors Influencing 2026 Prices
Beyond the frame and style, several technical specifications will alter your quote:
- Glazing Type: While double glazing is standard, triple glazing is becoming more common in towns and cities to combat noise pollution and heat loss. Triple glazing typically adds 20–30% to the unit cost.
- U-Values and Energy Ratings: High-performance energy rated windows that achieve an A++ rating use low-emissivity glass and argon gas fills, which add a slight cost but offer long-term savings on energy bills.
- Specialist Finishes: Custom RAL colours or dual-colour frames (different colours inside and out) typically add 10–15% to the manufacturing cost.
- Security Upgrades: Upgrading to laminated glass or PAS 24 certified hardware for ground-floor windows is a wise investment for ground-floor windows, adding roughly £50–£100 per opening.
What a full-house replacement looks like
A common project for us is replacing 10 to 14 tired timber or early uPVC windows in a 1930s–1960s Thames Valley house. For a home that needs to keep a traditional look — a conservation area, or simply a period street — that usually means uPVC or aluminium sliding sash and flush casement frames, often with a wood-effect or heritage finish, chosen to match the original sightlines.
Work like this is typically fitted in three to five days, room by room, with the house kept weathertight throughout. A project of that size and specification generally lands somewhere between £9,000 and £16,000 including VAT and installation, though the only accurate figure is a fixed quote after survey. Ask to see photos of recent local jobs of a similar type.
Frequently Asked Questions
Can I get a quote online?
While we can provide rough estimates based on dimensions, we recommend a site survey. This allows us to assess structural integrity and access requirements. You can view our current offers for seasonal discounts.
How long does installation take?
A standard window installation for a whole house usually takes between 2 and 5 days. At Inspired Glazing, we ensure clean workmanship, disposing of all old frames and leaving your property weather-tight at the end of each day.
Are new windows worth the investment in 2026?
Yes. With energy prices remaining volatile, reducing heat loss through the building envelope is the most effective way to lower overheads. Furthermore, “Energy Class A” windows are now a significant selling point in the property market.
Get a Professional Quote Today
Understanding the replacement windows cost is the first step toward a more comfortable, secure, and efficient home. Whether you are looking for window repairs and replacements or a complete architectural overhaul with aluminium windows and doors in Ascot, Inspired Glazing provides the technical expertise you need.
We work across Windsor, Maidenhead, Ascot, Bracknell, Slough, Reading and the wider Thames Valley.
Contact us for a precise, no-obligation technical survey:
- Phone: 01753 965 005
- Online: Request a Call Back
- Visit Our Website: inspiredglazing.co.uk
Ensure your home is prepared for the future with glazing that combines aesthetic excellence with 2026-standard thermal performance. Call 01753 965 005 to speak with one of our specialists.