Window and Door Replacement Costs in the UK: A 2026 Guide

Windows and doors are the eyes and mouth of your home — and when they start failing, everything suffers. Draughty rooms, condensation, higher energy bills, and security concerns all point to the same solution: replacement. But with so many materials, glazing options, and installers to choose from, it's easy to overspend or make the wrong choice.

This guide breaks down the costs, options, and regulations so you can make an informed decision.

Frame Materials Compared

uPVC — The UK Default

uPVC dominates the UK window market with around 85% share, and for good reason.

• Cost per window: £400–£800 installed
• Lifespan: 20–25 years
• Maintenance: Almost none — occasional wipe down
• Energy rating: A or A+ available
• Colours: White as standard; anthracite grey, black, and cream increasingly popular (add 10–20%)
• Best for: Value for money, low maintenance, most property types

Aluminium — The Premium Choice

Aluminium frames offer the slimmest sightlines and a contemporary look, popular in extensions and modern renovations.

• Cost per window: £700–£1,400 installed
• Lifespan: 30–40 years
• Maintenance: Minimal — powder-coated finish lasts decades
• Energy rating: A-rated with thermal breaks
• Colours: Any RAL colour, dual-colour options available
• Best for: Extensions, modern homes, maximising glass area, bifold and sliding doors

Timber — The Traditional Option

Timber windows suit period properties and conservation areas, offering authentic character.

• Cost per window: £800–£1,600 installed
• Lifespan: 30–60+ years with proper maintenance
• Maintenance: Repainting every 3–5 years (or use Accoya/modified timber for less maintenance)
• Energy rating: A-rated available
• Best for: Listed buildings, conservation areas, Victorian/Edwardian/Georgian homes

Composite (Timber-Alu)

Timber inside for warmth and character, aluminium outside for weather resistance.

• Cost per window: £1,000–£2,000 installed
• Lifespan: 40+ years
• Maintenance: Very low externally, occasional internal treatment
• Best for: High-end renovations wanting the best of both worlds

Window Costs by House Size

| Property | Windows | uPVC | Aluminium | Timber | |---|---|---|---|---| | 2-bed flat | 5–6 | £2,500–£4,500 | £4,000–£7,500 | £4,500–£9,000 | | 2-bed terrace | 6–8 | £3,000–£5,500 | £5,000–£9,000 | £5,500–£11,000 | | 3-bed semi | 8–10 | £4,000–£7,500 | £7,000–£12,000 | £7,500–£14,000 | | 4-bed detached | 12–16 | £6,000–£11,000 | £10,000–£18,000 | £11,000–£22,000 |

Add 20–35% for London and the South East. Browse window and door repair costs by city for your area, or use our repair cost calculator for a personalised estimate.

Door Costs

| Door Type | uPVC | Composite | Timber | Aluminium | |---|---|---|---|---| | Front door | £500–£1,000 | £800–£1,800 | £1,000–£3,000 | £1,500–£4,000 | | Back door | £400–£800 | £600–£1,200 | £800–£2,000 | £1,200–£3,000 | | French doors (pair) | £800–£1,500 | N/A | £1,500–£3,500 | £2,000–£4,500 | | Patio sliding doors | £1,200–£2,500 | N/A | £2,000–£4,000 | £2,500–£5,000 | | Bifold doors (3-panel) | £2,000–£3,500 | N/A | £3,500–£6,000 | £3,000–£6,000 |

A new front door is one of the highest-ROI improvements you can make — it transforms kerb appeal and costs under £2,000 for a quality composite.

Double vs Triple Glazing

| Feature | Double Glazing | Triple Glazing | |---|---|---| | U-value | 1.2–1.4 W/m²K | 0.7–0.9 W/m²K | | Cost premium | Baseline | +20–30% | | Energy saving vs single | £100–£200/year | £130–£250/year | | Noise reduction | Good (30–35 dB) | Excellent (35–40 dB) | | Weight | Standard | 50% heavier (frame must support it) | | Payback period vs double | N/A | 30–50+ years on energy savings alone |

Verdict: Double glazing is the sweet spot for most UK homes. Triple glazing makes sense for passive house builds, very exposed properties, and rooms where noise reduction is a priority. The energy payback alone rarely justifies the premium.

Energy Ratings Explained

Windows in the UK are rated on a scale from A++ to G by the British Fenestration Rating Council (BFRC):

• A++ / A+: Best available — U-values of 0.8–1.0
• A: Standard for new installations — U-value of ~1.2
• B: Adequate — U-value of ~1.4
• C and below: Below current Building Regulations minimum for new installations

Building Regulations require replacement windows to achieve a U-value of 1.6 W/m²K or better. In practice, all reputable manufacturers offer A-rated windows as standard, which comfortably exceed this.

FENSA and Building Regulations

All replacement windows and doors in England and Wales must comply with Part L (energy efficiency) and Part N (safety glazing) of the Building Regulations.

The simplest route to compliance:

1. Use a FENSA-registered installer — they self-certify the work and notify your local council automatically. You receive a FENSA certificate, which you'll need when selling.
2. Alternative: Use a non-FENSA installer and apply for Building Regulations approval yourself (£200–£400 plus inspections).

Without FENSA certification or Building Regulations approval, you'll face problems when selling — solicitors will flag the absence, and you may need to buy indemnity insurance (£150–£300) or apply for retrospective regularisation.

When to Repair Instead of Replace

Full replacement isn't always necessary:

| Problem | Repair Option | Cost | |---|---|---| | Misted sealed unit | Replace glass unit only | £50–£120 per pane | | Draughty frame (uPVC) | Replace rubber gaskets/seals | £30–£80 per window | | Stiff or jammed mechanism | Replace hinges/handles | £50–£150 per window | | Timber rot (localised) | Splice repair + redecorate | £100–£300 per window | | Condensation on inside | Improve ventilation (trickle vents) | £50–£100 per window | | Single glazing (timber) | Fit secondary glazing | £100–£300 per window |

Rule of thumb: If frames are structurally sound and less than 15 years old, repair the failing component. If frames are warped, rotten, or the design is fundamentally outdated (single-glazed, no trickle vents), replacement is the better investment.

Conservation Areas and Listed Buildings

If your home is in a conservation area or is listed:

• Conservation areas: Replacement windows must match the original style and proportions. Your council may require timber sash windows rather than uPVC casements. Check with your local planning officer before ordering.
• Listed buildings: You need listed building consent for any window or door changes — even repainting in a different colour. Unauthorised changes are a criminal offence. Budget for bespoke timber windows that replicate the originals exactly (£1,000–£2,000+ per window).

Next Steps

1. Assess your current windows — check for misting, draughts, rot, and stiffness
2. Decide on material — uPVC for value, aluminium for modern looks, timber for period character
3. Get 3 quotes from FENSA-registered installers — see our guide to getting builder quotes
4. Check for grants — some local councils offer energy efficiency grants that include window upgrades
5. Get a repair estimate — use our repair cost calculator for a personalised figure
6. Check our glossary for terms like U-value, trickle vent, and FENSA