Windows, doors and glazing

What should you ask if later plaster has buried the sash boxes so the weights cannot be seen?

Ask the surveyor to record that the boxes were concealed, not to guess the weights. On many older sashes the weights hang beside the frame, and later plaster or lining has buried the pockets, so a home survey will not chop plaster off to find a cord. A sash that opens on the day has not proved the hidden weight is sound, and buried boxes are a limit rather than rotten timber.

Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.

What is the fuller explanation?

The staff bead and the pocket cover are how a joiner reaches a weight. If those covers are plastered over, the inspection stops at the face. The surveyor can still see whether the sash moves, whether the cord is broken on the visible side, and whether the stile is soft. They cannot see a detached weight, a mouse nest or a rotten pulley stile behind the plaster. None of the concealed parts are guaranteed sound. The report should use a limitation, not a pass.

If you need the weights before you commit, that is an agreed opening-up, not a standard visit, and it damages finishes. There is no RICS price for replastering afterwards. Do not strip pocket covers the week of exchange without a plan. A window that will not stay open still points to the cords, with the added limit that you cannot see the repair. Buried boxes are also not a building-regulations question by themselves. They are an inspection limit on an old window.

What should you ask your surveyor?

Were the weight pockets visible, plastered over, or not identified?
Which sashes did you operate?
Are you calling the hidden weights not inspected rather than sound?

What are the typical next steps?

Do not knock plaster off the boxes on a viewing.
If a cord is broken and the pocket is buried, tell the joiner both facts.
Read “not inspected” on those pockets as a limit, not as a clean bill.

Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.

Also asked about this

Are all sash windows built with weight boxes?

Many older ones are. Some later sashes use springs. The survey should describe the window it saw, not assume a weight it could not find.

Does panelling in a bay hide the same thing?

Yes, if it covers the pocket. Panelling is not a survey of the weight.