Subsidence, settlement and heave
The bay is pulling away from the main wall and the bay foundation was not seen. What is still only a gap?
The separation is still only a gap. The bay pulling away from the main wall was seen at the junction. The bay foundation was not seen, so this visit does not know whether that base has dropped, whether the main wall has stayed put, or whether the bay was never tied. What you have is an open junction above ground. You do not have a foundation inspection or a cause. The report records the gap and the unseen base. It has not turned the gap into a diagnosed failure.
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?
Bays part from main walls when the junction no longer holds the two together. The sign is a gap in render, plaster or the brick joint, sometimes wider at the top or the bottom. Each pattern suggests ideas, such as rotation, settlement or a tie that was never built. Ideas are not findings while the foundation stays buried and unexposed. The surveyor did not dig beside the bay. Below ground is unknown. Above ground the evidence is the separation, which is the gap.
Tell your solicitor the bay is pulling away and the foundation was not seen. If the report asks for a structural engineer, that request is still open. Do not tell a lender the bay foundation has failed. The survey has not said that. It has said there is a gap and that the base was not inspected. Monitoring or an engineer's assessment would be further work. Filling the gap would hide the evidence and leave the same unknown underground. What is established is the gap itself.
What should you ask your surveyor?
- Where is the gap widest, and does the report stay with that description?
- Is cracking also noted in the main wall, or only at the bay junction?
- Has the report already asked for an engineer because the foundation was unseen?
What are the typical next steps?
- Describe the defect as a gap at the junction, with the foundation not seen.
- Do not state a foundation failure the survey did not establish.
- If you need a cause, instruct the further look this visit could not make.
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
Does a gap that has not grown this year mean the bay is stable?
Not from this survey. One visit has no earlier measurement of its own unless the report quotes a previous record. Someone's memory of a quiet year is not the same as a seen foundation. The gap is a present fact. Whether it is stable over time has not been established here.
Can the bay foundation be exposed as a casual extra?
Do not dig beside the bay as an informal addition to the survey. Excavation can undermine the footing you want to understand, and it is not a designed investigation. The survey left the foundation unseen for that reason. If it must be seen, an engineer should direct how. Until then the evidence is the gap.