Subsidence, settlement and heave
What is crack monitoring, and who instructs it before you exchange?
Crack monitoring is a series of measurements over time to see whether a crack is still moving. You instruct it, with the seller’s permission, or an insurer instructs it if a claim is open. A single survey visit cannot do that job, because it only sees one day.
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?
Telltales, pins or a digital gauge are fixed across the crack and read more than once. The period is set by the engineer or the monitoring firm, not by a national rule in the home-survey standard. It may be longer than the time you hoped to spend before exchange. That is a practical problem, not an emergency slogan. You can still choose to wait, to renegotiate, or to withdraw if the contract lets you.
The seller must agree to fittings on their wall. Your solicitor asks. The surveyor can say whether monitoring is what they recommended. They do not read the gauges unless you appoint them to. Fees vary with the number of visits. Ask the firm for the programme and the price before you start, and ask what a result would need to show to change the advice.
What should you ask your surveyor?
- Did you recommend monitoring, or a one-off engineer’s visit?
- Which cracks would be worth measuring?
- What could a single extra visit prove that monitoring could not?
What are the typical next steps?
- Decide whether you can wait for the programme. If you cannot, do not pretend a one-day revisit is monitoring.
- Get the seller’s consent in writing before anyone glues a telltale to the wall.
- Share the surveyor’s wording with the firm so they measure the crack that matters.
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
Is a photograph each month the same as monitoring?
It is better than nothing and worse than a fixed gauge. It is not what an engineer usually means. Ask them what they will accept.
Can you exchange and monitor afterwards?
Only if you are willing to own the result. After exchange in England and Wales you are generally bound. Ask your solicitor before you rely on a later reading.