What Does Secondary Glazing Cost?
Quick Answer
£250–£700 per window supplied and fitted
Full spread across 2026 guides: BookaBuilderUK £250–£700, Checkatrade £300–£500 per window. Supply-only panels run £180–£400 by style. The usual listed-building alternative to replacing original windows. Guide prices, not quotes
Cost per Window by Panel Type (2026 UK)
The table collates MyJobQuote (March 2026) supply prices with the fitted bands published by BookaBuilderUK, Checkatrade and specialist installers. Fitting labour is modest (roughly £65–£75 per window on multi-window jobs), so supply price drives the bill. Where guides disagree, the range shows the full spread.
| Panel type | Guide price per window | Notes |
|---|---|---|
| DIY magnetic or clip-on kit | ~£60–£150 | Retail kit pricing, indicative only: not covered by the major cost guides. Acrylic panel on magnetic tape; removable for summer |
| Lift-out panel | £180–£250 | Supply only (MyJobQuote); the cheapest professionally made option |
| Horizontal slider | £200–£300 | Supply only; the standard choice for casement windows you still want to open |
| Vertical slider (for sash windows) | £220–£325 | Supply only (MyJobQuote); specialist installers price sash installations fitted at £364–£572 because of the precise fitting involved |
| Hinged casement panel | £275–£400 | Supply only; best where you need full, frequent access to the original window |
| Supplied and fitted, typical window | £250–£700 | Full spread across 2026 guides: BookaBuilderUK quotes £250–£700, Checkatrade £300–£500, and specialist installers £312–£520 as the typical spend |
Whole-House Examples
MyJobQuote’s March 2026 guide prices complete installations (materials plus labour) like this:
| Property | Guide total | Time on site |
|---|---|---|
| 4 windows | £1,350–£1,950 | Half a day to a day |
| Small terrace (8 windows) | £2,750–£3,325 | 1–2 days; specialist installers quote around £3,120 for a 3-bed house, so the guides agree here |
| Semi-detached (10 windows) | £3,700–£4,200 | 1.5–2.5 days |
| Detached (15 windows) | £5,475–£6,150 | 3–4 days |
Why Choose Secondary Glazing?
- Listed buildings and conservation areas: it leaves the original window untouched, so it is usually the only glazing upgrade conservation officers accept. Listed building consent may still be needed, but there is no application fee for it
- Noise: with a 100–150mm cavity and heavier glass, specialists quote noise reductions of up to around 80%; it outperforms double glazing for sound because of the wide air gap. Compare options with the acoustic glazing calculator
- Heat: research for Historic England measured heat loss through traditional windows cut by over 60% where the secondary panel uses low-emissivity (Low-E) glass; standard float glass achieves less, so pair it with draught-proofing the original sashes
- Cost: a fitted panel at £250–£700 is far cheaper than a £1,200–£3,500 replacement timber sash window
Glass Options
- 4mm float glass: the standard, cheapest fill
- 6.4mm+ acoustic laminate: the noise-reduction choice; priced per job, expect a meaningful premium over float glass
- Low-E glass: better thermal performance for a small uplift; check the combined effect with the window U-value calculator
- Toughened or laminated safety glass: required in critical locations, such as glazing below 800mm from floor level (Approved Document K)
What Affects the Price
- Window size and count: pricing is per window and scales with glass area; large Victorian sashes sit at the top of each band
- Panel style: lift-out is cheapest, hinged dearest; vertical sliders carry a fitting premium
- Glass spec: acoustic laminate and Low-E cost more than float
- Access: ground-floor work is quick; tall stairwell or second-floor windows take longer
- Colour matching: powder-coating frames to match period joinery adds cost
Important Notes
- All figures are guide prices from published 2025–2026 UK cost guides, not quotes: get at least three itemised quotes
- Secondary glazing is normally fitted to the room side of the existing window and needs no FENSA notification, unlike replacement windows
- In listed buildings, speak to the conservation officer first; slim, colour-matched systems are far more likely to be approved
Figures cross-checked against published UK cost guides July 2026. Last updated: July 2026