Triple Glazing Cost
2026 UK pricing for triple glazed windows: supply, installation, and whole-house costs.
Last reviewed: 2026-06-27 • Reading time: 4 minutes
Triple glazing costs £800–£1,200 per window for a standard casement (1.2m × 1.2m), including supply and installation. Sash windows cost £1,200–£1,800. A 3-bedroom semi (12 windows) costs £9,600–£14,400 for triple glazing vs £4,800–£7,200 for double glazing.
Cost per Window (2026 UK Prices)
| Window Type | Triple Glazing | Double Glazing |
|---|---|---|
| Casement (1.2m × 1.2m) | £800–£1,000 | £400–£500 |
| Tilt & turn (1.5m × 1.5m) | £1,000–£1,200 | £500–£600 |
| Sash window (1.0m × 1.5m) | £1,200–£1,800 | £600–£900 |
| Patio door (2.5m × 2.1m) | £2,000–£3,000 | £1,000–£1,500 |
Whole-House Cost
- 3-bedroom semi (12 windows)
- £9,600–£14,400 (triple) vs £4,800–£7,200 (double)
- 4-bedroom detached (18 windows)
- £14,400–£21,600 (triple) vs £7,200–£10,800 (double)
- 1-bedroom flat (6 windows)
- £4,800–£7,200 (triple) vs £2,400–£3,600 (double)
Cost Breakdown
Triple glazing costs break down as:
- Triple glazed unit (material): £300–£450/m² (vs £150–£250/m² for double)
- Frame (uPVC, timber, or aluminium): £150–£300 per window (same for triple and double, though triple may need reinforced frames)
- Installation labour: £150–£250 per window (same for both)
Getting Quotes
Get at least 3 quotes from FENSA or Certass-registered installers. Ask for:
- U-value of the complete window (frame + glazing, should be 0.8 W/m²K or better)
- Glass specification (low-e coating, argon or krypton fill)
- Frame material and reinforcement (heavier triple glazing may need upgraded hardware)
- Warranty (10–20 years typical for sealed units)
- Disposal of old windows (included or extra cost?)
Last reviewed: 2026-06-27