New builds and warranties
What should you do if a crack appears after completion and a warranty is in force?
Record it, tell the builder or the warranty provider in the way the policy requires, and do not cover it up. NHBC’s Buildmark, where that is the policy, makes the builder responsible for defects that breach NHBC requirements in the first two years, and then insures damage from defects in specified parts. A crack in paint may be neither. A crack in masonry may be. The policy wording decides.
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?
A pre-completion survey cannot mention a crack that had not appeared. That does not stop you notifying it later. Take dated photographs and a note of when you first saw it. Do not repoint it before the warranty inspection, or the inspector will be looking at your mortar. Do not assume it is subsidence. New homes also crack as they dry. The Association of British Insurers’ subsidence advice is a different route, for an insured peril, and it may not be the warranty route.
Send the original survey if it described the same area as sound, because that helps the timeline. It is still not the claim form. If the provider says the crack is not covered, you then decide whether to instruct your own investigation. Costs of that investigation vary. Get a scope before you pay for underpinning the sales office suggested.
What should you ask your surveyor?
- If we surveyed before completion, what did we actually say about this wall?
- What should we not do to the crack before a warranty inspector sees it?
- Which photos and dates would make the later notification useful?
What are the typical next steps?
- Notify in the form the policy requires, with dates and photographs.
- Leave the crack visible until it has been inspected for the claim.
- If cover is refused, ask in writing why, and only then decide on your own engineer.
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 hairline crack in plasterboard fall under the structural insurance years?
Usually you should expect the policy to distinguish finishes from the parts it insures later. Read it. Do not file a year-nine claim for a joint crack without checking.
Can you claim against the surveyor because they did not predict the crack?
Only in the legal sense your solicitor explains, and only if the surveyor was negligent, which a crack that appears later does not prove. Notify the warranty first.