Cost guide
How much do sash windows cost?
Refurbishing a box sash window costs £350 to £750 per window, including new cords, draught proofing and localised rot repair. Replacing one with a new timber sash is £1,200 to £2,500.
Typical prices
Ranges, not quotes. A quote depends on your room.
| Work | Typical UK price |
|---|---|
| Re-cord one sash window | £150 to £300 |
| Draught proof one window | £150 to £300 |
| Full refurbishment, one window | £350 to £750 |
| Splice out rot, per repair | £120 to £400 |
| New timber box sash, supplied and fitted | £1,200 to £2,500 |
Refurbishment is nearly always cheaper than replacement and in a listed building it may be the only permitted option. Price both before deciding.
What moves the price
- Extent of rot. Cords and beads are quick; splicing a sill or bottom rail is not.
- Draught proofing, usually £150 to £300 per window on its own.
- Size and access. Upper-floor windows need scaffold or a tower.
- Glazing. Retaining original glass costs nothing; slim double glazing adds £400 to £900 per window.
- Listed building or conservation area consent, where required.
What the money buys: cord and weight replacement.
Who quotes for it
96 of the 1,142 carpenters and joiners listed on this site take on sash windows.
Where most of them are based: Hammersmith and Fulham (4), Southwark (4), Exeter (3), Islington (3), Chester (3).
Questions about sash windows
Can I get double glazing in a sash window?
Slim units can often be fitted into existing or new sashes. The sash may need deepening and the counterweights re-balanced, and in a listed building it needs consent.
Why does my sash window not stay open?
Nearly always a broken or stretched cord, or weights that no longer match the sash after it was repaired or reglazed.