New builds and warranties
What should you ask if the corridor outside a new flat is unfinished on survey day?
Ask for the unfinished parts to be listed as not complete, not as a passed common area. A home survey can only rate what exists. NHBC describes Buildmark as a 10-year warranty and insurance, with the builder responsible in the first two years and insurance for certain defects after that. An unfinished corridor is a completion question, not automatically an insurance claim.
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?
Snagging lists and RICS condition ratings are different documents. A missing handrail, wet plaster or no fire door in a corridor should be written as incomplete. The survey does not issue the building-control completion certificate and does not bind NHBC. Other warranties are not Buildmark. Read the policy you were actually given.
Your solicitor asks what must be finished before completion and what the contract says if it is not. There is no RICS retention figure for a corridor. Do not invent one. Do not accept a verbal “the builder will be back” without it being in the contract.
What should you ask your surveyor?
- Which common parts were unfinished, and which did you not enter?
- Are you rating them, or recording that they were not there to rate?
- Is any warranty paper inside your report? It should not be, unless you were given it.
What are the typical next steps?
- List the unfinished items for the solicitor and the site manager.
- Do not treat a show-flat corridor as this block’s corridor.
- Revisit before completion if the contract gives you that chance. The first survey cannot see next month’s work.
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 Buildmark finish the corridor?
No. In the early period NHBC says the builder is responsible for defects. Incomplete work is first a contract matter. Read the policy.
Is an unfinished lift a condition rating 3?
Only if the surveyor applies the rating to something they could inspect. A lift that is not installed is incomplete. Say that plainly.