Subsidence, settlement and heave
An underpinning drawing covers one bay and the crack the survey describes is on another wall. What of that other wall was not in the drawing?
Nothing of that other wall is in the underpinning drawing. The sheet covers one bay, and the crack the survey describes sits on a different wall, so the cracked length was never on the page. The survey has recorded the crack and the bay the drawing actually covers. It has not decided that the other wall was underpinned, monitored, or left out of the scheme. A bay that has been drawn and pinned is not a finding about masonry the sheet omits. The Association of British Insurers explains how subsidence can affect a home. This inspection has not treated the unmarked wall as repaired.
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?
Underpinning is a local repair: new support goes under a stated length of foundation, and the drawing should name that length. A crack on a different wall may be the same movement, an older scar, or something else, and a sheet for one bay cannot choose. The survey can set the crack it saw beside the bay on the drawing. It cannot invent pins or a schedule for a wall the drawing does not name. Seeing the crack does not measure movement since that bay was done.
Ask the solicitor for the claim papers: the drawing, any engineer's report, and what the insurer treated as the extent of the work. The Association of British Insurers describes what to do when subsidence happens, and those papers sit apart from the home survey. Put the other wall to that file. Do not tell a lender the whole house was underpinned because one bay has a drawing. The survey has not said that.
What should you ask your surveyor?
- Which bay does the underpinning drawing actually cover?
- Is the crack you describe on a wall that drawing does not show?
- Have you left the other wall outside any finding that it was underpinned?
What are the typical next steps?
- Treat the drawing as cover for one bay only.
- Ask the solicitor for the claim papers on the other wall.
- Do not describe the unmarked wall as underpinned.
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
If the bay on the drawing looks straight, is the cracked wall stable?
No. A straight bay shows that length, not the wall with the crack. The survey has not monitored the other wall and has not decided it is stable or still moving. The drawing never included it. Straightness on one bay is not a reading of a different wall.
Can the survey add the other wall onto the underpinning scheme?
No. The survey records what was drawn and what it saw. It does not redraw an insurer's scheme or decide that pins should be extended under the cracked wall. That would be a later design, if anyone commissions one. The other wall stays outside the drawing.