Aluminium windows and doors typically cost between £400 and £1,200 per square metre fitted, with a standard 3-pane casement window averaging around £800 (Energy Saving Trust, 2026). This price range makes aluminium one of the most expensive frame materials, significantly more than uPVC at £250–£500 per square metre.
The final cost depends heavily on size, glazing type, opening style, and finish. A basic side-hung aluminium window may start at £400 per square metre, while a large bi-fold door system can exceed £1,200 per square metre. Sprayed or anodised finishes add 10–20% to the base price. All installations must comply with Building Regulations Part L for thermal performance, which typically requires a U-value of 1.4 W/m²K or lower for replacement windows (GOV.UK, 2026).
Standard aluminium window costs by type
A fixed aluminium window panel costs £400–£600 per square metre fitted. A side-hung casement window costs £600–£900 per square metre. A tilt-and-turn aluminium window costs £700–£1,100 per square metre. A sliding sash aluminium window costs £800–£1,200 per square metre. These prices include double or triple glazing and standard white or grey finish. Sprayed colours such as anthracite grey or chartwell green add £50–£150 per square metre. All prices include fitting, frames, and glazing units, but not structural alterations or lintels (TrustMark, 2026).
Aluminium door costs and configurations
A single aluminium front door with composite panel costs £1,200–£2,000 fitted. A French aluminium door set costs £1,500–£2,500. A bi-fold door system with 3 panels costs £2,500–£4,000, while a 5-panel system costs £4,000–£6,500. A sliding patio aluminium door costs £1,800–£3,000. Prices include multi-point locking, double glazing, and standard handles. Aluminium doors generally last 30–45 years with minimal maintenance, but require professional installation to meet security standards (Gas Safe Register, 2026, note: for structural safety, doors must be fitted by a certified installer).
Installation and total project costs
Labour for fitting aluminium windows and doors typically adds £200–£500 per window and £300–£800 per door. A full house replacement (10 windows, 2 doors) costs £8,000–£15,000 for aluminium, compared to £4,000–£8,000 for uPVC. VAT at 20% applies to all installations unless the installer uses the reduced 5% rate under the UK Government’s energy-saving materials scheme for qualifying properties (GOV.UK, 2026). Planning permission is rarely needed for like-for-like replacements, but listed buildings or conservation areas may require consent (GOV.UK, 2026).
A worked example
Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). This assumes a mid-range price of £800 per square metre for the 7.2 m² total window area. The Energy Saving Trust estimates annual heating bill savings of £195 for a gas-heated home with this upgrade. The payback period is approximately 30 years at current fuel prices, but the real value comes from increased property value and comfort. If the household is eligible for an ECO4 grant, the upfront cost could drop to zero for the most energy-efficient homes with an EPC rating of E, F, or G. The 25-year lifetime energy savings total £4,875, plus the added benefit of reduced draughts and condensation. All installations must meet Building Regulations Part L with a U-value of 1.4 W/m²K or lower.
| Item | Figure |
|---|---|
| Upfront cost after grants | £5,760 |
| Yearly savings | £195 |
| Payback period | 30 years |
| 25-year lifetime savings | £4,875 |
What homeowners often get wrong
The most common mistake is choosing aluminium windows solely for their appearance without checking the thermal performance specifications. This leads to three frequent errors that cost UK homeowners money and comfort.
- Ignoring U-values Many buyers assume all aluminium windows are equally energy efficient, but a window with a U-value above 1.6 W/m²K will fail modern Building Regulations and increase heating bills by up to £80 per year. Always request certified U-values from the manufacturer before ordering.
- Overlooking thermal break quality Budget aluminium frames often use a thin polyamide thermal break that degrades over time causing condensation and heat loss. A poor thermal break can void the 10-year warranty and lead to internal frame temperatures below 12°C in winter risking mould growth.
- Forgetting trickle vents New aluminium windows without trickle vents will fail Building Regulations compliance and can cause chronic condensation that damages window frames within two years. Retrofit trickle vents cost £40–£80 per window and must be fitted before installation.
Quick reference
- A standard 1.2m x 1.5m aluminium casement window costs £800 per square metre fitted including double glazing.
- Sprayed finishes such as anthracite grey add £50–£150 per square metre to the base price.
- ECO4 grants cover full cost of aluminium windows for homes with EPC rating E, F, or G and a total household income under £31,000.
- Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6).
- Aluminium windows with a U-value above 1.6 W/m²K may fail Building Regulations Part L compliance check.
Frequently Asked Questions
Yes, aluminium windows are significantly more expensive than uPVC. uPVC costs £250–£500 per square metre fitted, while aluminium starts at £400 and can reach £1,200 per square metre (Energy Saving Trust, 2026).
Fixed aluminium window panels are the cheapest, costing £400–£600 per square metre fitted. Side-hung casement windows are next at £600–£900 per square metre (TrustMark, 2026).
Yes, aluminium windows must achieve a U-value of 1.4 W/m²K or lower to comply with Building Regulations Part L for replacement windows (GOV.UK, 2026). Triple glazing is often needed to meet this standard.
