What Does Secondary Glazing Cost?
Quick Answer
£100–£300 per window (DIY), £200–£500 fitted
For a standard 1200 × 1200mm window. Listed building alternative to full window replacement (2026 UK)
Cost by Type (2026)
- Magnetic panels (removable): £60–£150 per window (DIY). Cheapest option
- Hinged casement panels: £150–£300 per window (supply only)
- Horizontal sliding (sash): £200–£400 per window (supply only)
- Lift-out panels: £100–£200 per window
- Professional fitting: Add £50–£150 per window
Whole-House Examples
- 3-bed terrace (6 windows, DIY magnetic): £500–£900
- 4-bed detached (10 windows, fitted sliding): £3,000–£5,500
- Victorian terrace (6 sash windows, fitted): £1,800–£3,500
Benefits of Secondary Glazing
- Sound reduction: Up to 80% noise reduction (better than double glazing for sound)
- Thermal improvement: Reduces heat loss by 50–65%
- Listed buildings: Does not alter the original window, so usually permitted
- Conservation areas: No planning permission typically needed
- Draught elimination: Seals gaps in original windows
Glass Options
- 4mm float glass: Standard, cheapest
- 6.4mm acoustic laminate: Best for sound reduction
- Low-E glass: Better thermal performance
- Toughened glass: Required at low level or in bathrooms
Last updated: April 2026