Secondary Glazing Cost
2026 UK pricing: DIY kits vs professional installation, materials, and whole-house costs.
Last reviewed: 2026-06-27 • Reading time: 4 minutes
Professional secondary glazing costs £150–£400 per window (glass in aluminium or uPVC frames, fitted). DIY kits cost £30–£100 per window (acrylic panels, self-fit). A 3-bedroom semi (12 windows) costs £1,800–£4,800 (professional) or £360–£1,200 (DIY), compared to £4,800–£7,200 for replacement double glazing.
Cost per Window (2026 UK Prices)
| Type | Cost per Window | Material |
|---|---|---|
| DIY magnetic kit | £30–£60 | 3–4mm acrylic, magnetic strips |
| DIY frame kit | £60–£100 | 4–6mm acrylic, aluminium frame, clips |
| Professional (fixed) | £150–£250 | 4mm glass, aluminium frame, screwed to reveal |
| Professional (sliding) | £250–£350 | 4mm glass, horizontal or vertical sliding track |
| Professional (hinged) | £300–£400 | 4–6mm glass, hinged opening, acoustic-grade option |
Whole-House Cost
- 3-bedroom semi (12 windows), DIY
- £360–£1,200
- 3-bedroom semi, professional
- £1,800–£4,800
- Replacement double glazing (same house)
- £4,800–£7,200
- Savings vs double glazing
- £3,000–£5,400 (professional) or £3,600–£6,840 (DIY)
DIY vs Professional: What You Get
DIY kits (£30–£100 per window):
- Thin acrylic panels (3–4mm)
- Magnetic or clip-in attachment (removable)
- You measure, order, cut to size (if needed), and install
- Lifespan: 5–10 years (acrylic scratches, seals degrade)
- U-value improvement: 5.0 → 3.5–4.0 W/m²K (poor seal = air leakage)
- Good for: rental properties, temporary use, tight budgets
Professional installation (£150–£400 per window):
- 4–6mm glass (looks like a proper window)
- Slim aluminium or uPVC frames
- Screwed to window reveal or frame (permanent fixture)
- Brush seals or compression gaskets (airtight)
- Choice of fixed, sliding, or hinged opening
- Lifespan: 15–20 years
- U-value improvement: 5.0 → 2.5–3.0 W/m²K
- Good for: long-term use, listed buildings, noise reduction
Additional Costs
Surveyor visit: £50–£100 (free with order from some suppliers)
Acoustic-grade glass: +£50–£100 per window (laminated glass for extra noise reduction)
Colour matching: +£20–£50 per window (RAL colour for frames to match existing window frames)
Payback Time
Secondary glazing improves single-glazed windows from U-value 5.0 W/m²K to 2.5–3.0 W/m²K (professional) or 3.5–4.0 W/m²K (DIY). For a 3-bedroom house, this saves £150–£250/year on heating bills.
- DIY payback
- 2–5 years
- Professional payback
- 8–15 years
- Double glazing payback (vs single)
- 12–20 years
When DIY Is Enough
- You're renting (removable kits don't require landlord permission)
- You want a trial before committing to professional secondary glazing
- Budget is tight (£360–£1,200 whole house vs £1,800–£4,800)
- You only need winter insulation (remove in summer)
When Professional Is Worth It
- You own the property long-term (15+ years)
- You need maximum thermal performance (U-value 2.5–3.0 W/m²K)
- You need noise reduction (professional glass + airtight seals work better)
- Listed building (professional finish preserves aesthetics)
Full guide: Secondary Glazing →
Last reviewed: 2026-06-27