A new home snagging survey should be timed in two stages, once before legal completion while you still have leverage, and again once you have moved in and can see the property in daily use.
Why timing matters more than the checklist
Most advice on snagging a new home focuses on what to look for. Just as important is when you look. A new home snagging survey carried out at the wrong moment either misses defects that only show up once you live in the property, or finds them too late to matter for your legal position.
Legal completion is the hinge point. Before it, you still have some leverage because money has not changed hands for the final time. After it, you are relying on warranty cover and goodwill rather than a condition of sale.
Before legal completion: the pre-completion inspection
Under the New Homes Quality Code Version 2 (March 2026), buyers of a new build covered by the code have a right to a pre-completion inspection. You can appoint a professional from a recognised body such as CABE, CIOB, ICWCI, RICS or RPSA, provided they hold professional indemnity insurance, or you can carry out the inspection yourself using the NHQB checklist.
Where issues found at this stage breach the warranty provider’s technical standards, the code states the developer should address them, ideally before legal completion or within 30 days. That window is short, so a thorough walk-through at this stage, photographed and logged room by room, gives you the clearest paper trail if anything is disputed later.
After legal completion: your warranty clock starts
Once legal completion happens, your warranty period starts running. Under NHBC Buildmark, this means two years of builder warranty from the date of legal completion, followed by eight years of insurance cover for specified structural defects. NHBC also operates a free resolution service during the first two years if you and the builder cannot agree on a repair.
This is why a second snagging pass, done once you have lived in the property for a few weeks, is worth doing even if you had a pre-completion inspection. Doors that stuck in cold weather, seals that only leak in heavy rain, or flooring that lifts after central heating runs for the first time, these often only appear once the house is actually being used.
Two snagging surveys, not one
A practical approach for most buyers is to treat snagging as two separate events rather than a single visit:
- 1Pre-completion: inspect or appoint a professional before you legally complete, focused on anything that affects the warranty technical standards and the 30 day resolution window.
- 2Post-completion: a second walk-through once you have lived in the property for a few weeks, catching issues that only show under normal use.
Both visits benefit from the same discipline: photograph every defect, circle the fault, and keep the list grouped by room and by trade so a conversation with the developer or site manager is specific rather than vague. An app like SayScope lets you do this on the walk itself, you photograph the defect, circle it, hold a button and say what is wrong, and leave with a report split by room and trade rather than a page of loose notes.
What a professional survey costs and when it is worth it
A professional snagging survey typically costs £300 to £600 depending on the size of the property. For a pre-completion inspection under the New Homes Quality Code, this cost buys you a report from someone outside the sale, which can carry more weight with a developer than a self-conducted list, particularly on a larger or more complex build.
If you prefer to inspect yourself at both stages, the NHQB checklist gives you a structure to follow, and a tool that organises your photos and voice notes by room and trade makes it easier to present the same quality of report without paying for a professional each time.