Sash window repairs and restoration
Sash window restoration is the full overhaul of an original timber window so it runs, seals and lasts as it did when new.
We strip the sashes, cut out and splice rotten timber, renew cords, weights and pulleys, replace beads and putty, reglaze where needed and finish by hand. The original frame and most of the original timber stay in the building.
London · RestorationWritten quotationsA studio of The Barnsbury Group, established 1980
What we do
- 01Remove the sashes and staff beads, protect the room.
- 02Strip failed paint and putty; assess the timber properly for the first time.
- 03Cut out rot and splice in new timber, matched to the profile and grain direction.
- 04Renew sash cords, check weights and pulleys, rebalance so each sash holds at any height.
- 05Replace parting and staff beads; ease and adjust so the sashes run without binding.
- 06Reglaze with like-for-like glass where panes are cracked, or fit upgrades while the window is apart.
- 07Prime, undercoat and hand-paint, or leave keyed for your decorator.
- 08Refit, test every window with you, and set out any aftercare.
Restoration, refurbishment or renovation?
People use all three words for the same job, and we answer to any of them. If there is a distinction worth making, it is one of degree. Refurbishment usually means putting a sound window back into good working order: new cords, new beads, easing and rebalancing, a bit of filling and a fresh coat of paint. Restoration goes further, cutting out failed timber and splicing in new, replacing putty and glass, taking the window back to how it was made. Renovation is the word people reach for when the window is in poor condition and they want it brought back without replacing it. In practice we survey the window and quote for what it needs, whichever word you used when you called us.
Sash cords and weights
A broken cord is the most common single fault we are called out for, and on its own it is a small job rather than a restoration. We replace both cords on the sash in waxed cotton, check the weights are matched, and rebalance so it stays where you put it. Where that is all a window needs, see sash cord repairs. Where the box has been opened anyway, it is done as part of the overhaul.
Cost and time
We quote per window after a survey, itemised by task, because two windows on the same house can need very different work. Draught-proofing and glazing upgrades add little to a restoration because the window is already apart. Minor repairs are quoted and done separately.
What it does not fix
A box frame that has rotted through at the cill and pulley stiles, or a window that has already been replaced with a poorly made modern sash, is usually a replacement job. We will say so at the survey.
Common questions
How do I know if my sash windows need restoring rather than just painting?01
If the sashes stick, rattle or will not stay open, or the timber feels soft at the bottom rail or cill, painting alone will not help, because the rot carries on under new paint. The free digital survey from your photographs tells you which windows need restoring and which only need decorating.
Will restoring stop the draughts?02
Partly. Restoration closes some gaps by replacing worn beads and rebalancing the sashes, but draught-proofing is the full answer, and we fit it at the same time while the window is apart.
Can you restore just one window?03
Yes. We quote per window, itemised by task, so a single window is surveyed, quoted and restored on the same basis as a whole house.
Do I need to move out?04
No. Most of the work is done from inside and sequenced room by room, so the rest of the house stays usable. We protect floors and furniture with dust sheets throughout.
How much does it cost to replace a sash cord?05
It is quoted per sash after a survey, because opening the box often reveals other work. We replace both cords on the sash rather than just the broken one.
Can you replace a sash cord without taking the window out?06
The sashes and beads come out, but the box frame and the window stay in place and the work is done from inside the room.
Book a survey
Send us photographs of your windows and we'll tell you what needs doing and what doesn't, with a written quotation. The digital survey is free.