Subsidence, settlement and heave
Does a comment that a floor is out of level mean the surveyor monitored the house?
No. A sloping floor is something a surveyor can see or pace on the day. Monitoring is repeated measurement. An out-of-level floor can be how the house was built, how timber has deflected, or how the ground has moved. The Association of British Insurers’ definition of subsidence is downward movement of the ground. A slope, alone, is not that finding.
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?
Old houses are often out of level without a live problem. The survey should say whether the walls are cracked, whether doors catch, and whether the slope is in the timber floor or in the building as a whole. A springy timber floor is a different sentence from a brick wall that has dropped. RICS home surveys do not include a measured plumb survey unless the instruction says so.
Do not underpin because a marble rolls. Ask what else was seen. If the only comment is a gentle slope in an old suspended floor, a joist inspection is the nearer question. There is no RICS price for levelling a house. Get a quote only for the defect the report actually described.
What should you ask your surveyor?
- Is the slope in the floor timbers, the slab, or the walls?
- Are there cracks that match the slope?
- Did you take levels over time, or look once?
What are the typical next steps?
- Do not write “subsidence” on a price reduction if the report said the floor slopes.
- Ask whether the joists were seen.
- If an engineer is recommended, give them the slope and the cracks, not a demand for underpinning.
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 sloping window sill prove subsidence?
No. Sills are often built that way, or have settled locally. It is a clue only with the rest of the pattern.
Can furniture hide a slope?
Yes. The limitation should say if the floor was covered. Covered is not level.