Alt: Comparison of uPVC, aluminium and timber window frames on a UK house

uPVC windows cost £400-£600 per window installed and hold around 85% of the UK residential market (British Fenestration Rating Council). Aluminium runs £700-£1,000 per window with the slimmest sightlines available. Timber costs £800-£1,500 per window but lasts up to 60 years with maintenance. For a typical 3-bed semi needing 8-10 windows, expect to pay £4,000-£6,000 for uPVC, £6,000-£10,000 for aluminium, or £8,000-£15,000 for timber. All three materials now meet Part L building regulations when fitted with low-E double or triple glazing.

How do uPVC, aluminium and timber windows compare on cost and performance?

Prices based on standard casement windows, double glazed, including installation. Costs vary by region and specification. Sources: Checkatrade, FMB.

Which window material is cheapest for UK homes?

uPVC is the clear winner on upfront cost, typically 40-50% cheaper than timber and 30-40% cheaper than aluminium. A standard white uPVC casement window costs £400-£600 fully installed in 2026 (FMB). Woodgrain-effect or coloured uPVC adds 20-30% to the price but still undercuts aluminium.

For a 3-bed semi-detached house with 8-10 windows, the total cost breakdown looks like this:

• uPVC: £4,000-£6,000
• Aluminium: £6,000-£10,000
• Timber: £8,000-£15,000

The price gap narrows slightly with premium uPVC brands like Rehau or Liniar, which charge closer to £500-£700 per window for enhanced thermal performance and slimmer profiles.

Which window material lasts the longest?

Timber windows have the longest potential lifespan at 40-60 years, but only with regular maintenance every 3-5 years. Without painting or staining, timber can deteriorate within 10-15 years from moisture damage and rot.

Aluminium offers the best low-maintenance longevity at 30-45 years. Powder-coated aluminium frames resist corrosion, fading and warping with virtually no upkeep beyond occasional cleaning.

uPVC lasts 20-30 years before the frames yellow, become brittle, or the seals fail. Replacement is straightforward and cost-effective, and the shorter lifespan is offset by the lower initial investment.

When you factor in lifetime cost per year, all three materials come surprisingly close: uPVC at around £20-£25 per window per year, aluminium at £22-£28, and timber at £20-£30 (including maintenance costs).

Which window frame is most energy efficient?

uPVC and timber offer the best thermal insulation, with typical U-values of 1.2-1.4 W/m2K for double-glazed units. Aluminium conducts heat more readily, but modern thermally broken aluminium frames have closed the gap significantly, achieving U-values of 1.4-1.6 W/m2K (Energy Saving Trust).

The glazing unit itself accounts for around 80% of a window’s thermal performance. The frame material matters less than the glass specification, gas fill and spacer bars. All three frame types comfortably meet the current Part L requirement of 1.4 W/m2K or better for replacement windows in England.

For maximum energy efficiency regardless of frame material, specify:

• Low-E glass coating
• Argon or krypton gas fill
• Warm-edge spacer bars
• Triple glazing (if budget allows)

If you are upgrading from single glazing, any of the three materials will cut heat loss through windows by 50-70%, saving £100-£200 per year on heating bills for a typical home (Energy Saving Trust).

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What about planning permission and conservation areas?

If your property is in a conservation area or is a listed building, timber is usually the only permitted option. Local planning authorities typically require like-for-like replacement, which means timber sash or casement windows matching the originals in material, profile, and glazing bar pattern.

Some conservation officers now accept slim-profile aluminium or high-quality uPVC where the appearance closely matches the original. However, approval is never guaranteed and varies by council. Always check with your local planning department before ordering.

For listed buildings specifically:

• Grade I and II*: Almost always require timber, may need single glazing retained with secondary glazing added internally
• Grade II: Timber replacement usually accepted; slim-profile double glazing increasingly approved
• Conservation areas (unlisted): Timber preferred but sympathetic uPVC or aluminium sometimes accepted

Which window material should you choose?

The right choice depends on your priorities:

• Best value for money: uPVC. Lowest cost, good insulation, low maintenance. Suits the vast majority of UK homes.
• Best for modern homes: Aluminium. Slimmest frames maximise glass area, creating a contemporary look. Ideal for extensions, bifold doors, and new builds.
• Best for period properties: Timber. Authentic appearance, excellent insulation, longest lifespan. Essential for listed buildings and conservation areas.
• Best compromise: Aluminium-clad timber. Timber interior for warmth and aesthetics, aluminium exterior for weather protection. Costs £1,000-£2,000 per window.

FAQ

Are uPVC windows as good as aluminium?

For thermal performance, uPVC is actually slightly better than aluminium, with typical U-values of 1.2-1.4 W/m2K compared to 1.4-1.6 W/m2K. uPVC costs 30-40% less. Aluminium wins on aesthetics, frame slimness and lifespan. For most UK homes, uPVC offers the best overall value.

How long do uPVC windows last before they need replacing?

uPVC windows typically last 20-30 years. Signs they need replacing include yellowing or discolouration, condensation between panes (seal failure), difficulty opening or closing, and visible cracks in the frame. Premium uPVC with reinforced profiles can push beyond 30 years.

Can I get timber-look windows in uPVC?

Yes. Most uPVC manufacturers offer woodgrain foil finishes in oak, rosewood, mahogany and other wood effects. These cost 20-30% more than standard white uPVC but still less than real timber. Quality has improved significantly, though they are unlikely to satisfy conservation officers for listed buildings.

Do aluminium windows cause condensation?

Older aluminium windows without thermal breaks were notorious for condensation. Modern thermally broken aluminium windows have an insulating barrier within the frame that prevents cold bridging, virtually eliminating condensation issues. Always specify thermally broken profiles.

Which windows add the most value to my home?

All new windows add value, but high-quality aluminium or timber windows can add 5-10% to property value for the right home. uPVC replacement windows are expected on most properties and their absence (i.e., old single glazing) detracts from value rather than new uPVC adding a premium.

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