SiteSnagChecklists
Common new build defects
Updated 19 October 2026
Most of the library is about new homes, with further categories for surveys of older houses and for commercial handovers. In the app, you start typing a defect’s name in the camera and pick it from the suggestions, and the description, severity, trade and reference are filled in for you. This page gives you the same list to browse.
Defects by category
Categories with five or more entries have their own page listing every defect in full.
| Category | Defects |
|---|---|
| Decoration | 20 |
| Walls & ceilings | 19 |
| Doors & joinery | 38 |
| Windows & glazing | 22 |
| Floors | 16 |
| Tiling | 12 |
| Kitchen | 42 |
| Bathroom | 29 |
| Plumbing | 17 |
| Heating | 15 |
| Electrical | 28 |
| External | 33 |
| General | 9 |
| Ventilation | 6 |
| Insulation & damp | 10 |
| Roofing | 18 |
| Drainage | 8 |
| Garage | 5 |
| Fire safety | 17 |
| Accessibility | 8 |
| Commercial fit-out | 10 |
| Mechanical & electrical | 11 |
| Lifts & doors | 5 |
| Car park & external works | 7 |
| Signage & security | 6 |
| Welfare & WCs | 4 |
| Utility | 3 |
| Fitted furniture | 7 |
| Stairs | 6 |
| Structure | 8 |
| Timber & pests | 8 |
| Loft | 4 |
| Balconies & terraces | 4 |
| Communal areas | 6 |
How serious each defect is
Every entry carries one of five severity levels, which an inspector can change for the job in front of them.
- Critical7 entries cover risks to life or to the building that need reporting straight away.
- Safety52 entries cover faults that could injure someone, such as a missing window restrictor or a loose handrail.
- Major51 entries cover faults that stop something working or will get worse if they’re left.
- Moderate146 entries cover faults that need a tradesperson to come back but won’t cause harm in the meantime.
- Minor205 entries cover cosmetic and finishing faults, such as a paint run or an open mitre.
The most serious entries
These 7 are marked critical in the library. 5 of them are fire safety items, which matter most in flats and commercial buildings where people rely on compartments and escape routes.
| Defect | Category | Reference |
|---|---|---|
| Leaking pipework / fitting | Plumbing | NHBC Standards 8.1 |
| Roof edge protection missing | Roofing | Work at Height Regulations 2005 |
| Fire stopping incomplete at penetrations | Fire safety | Approved Document B |
| Compartment wall / floor breached | Fire safety | Approved Document B |
| Cavity barriers missing | Fire safety | Approved Document B |
| Escape route obstructed | Fire safety | Approved Document B |
| Final exit not openable without a key | Fire safety | Approved Document B |
Safety items to look for in a house
On a new build house, the safety entries you’re most likely to need are in the rooms you walk through every day. These 30 come from the categories for doors, stairs, windows, rooms, services and the outside.
| Defect | What to do |
|---|---|
| Fire door not self-closing Doors & joinery, Approved Document B | Fire door does not fully close under its own closer. Adjust closer so door closes and latches. |
| Loose handrail / balustrade Doors & joinery, Approved Document K | Handrail or balustrade is loose. Secure firmly. |
| Window restrictor missing Windows & glazing, Approved Document K | Window restrictor missing or not working. Fit/adjust restrictor. |
| Smoke alarm not working Electrical, Approved Document B | Smoke/heat alarm does not respond to test. Repair or replace immediately. |
| Exposed wiring Electrical, BS 7671 | Live wiring or terminals exposed. Make safe immediately. |
| Uneven paving / trip hazard External, NHBC Standards 10.2 | Paving slabs uneven, creating a trip hazard. Re-lay level. |
| Fire door gap excessive Doors & joinery, Approved Document B | Gap between fire door leaf and frame is excessive (typically over 4 mm) or uneven. Adjust or replace leaf. |
| Intumescent / smoke seals missing Doors & joinery, Approved Document B | Intumescent strips or smoke seals missing or painted over on fire door. Fit correct seals. |
| Balustrade gap over 100 mm Doors & joinery, Approved Document K | Gap between balusters or under handrail allows a 100 mm sphere to pass. Infill to comply. |
| Stair headroom insufficient Doors & joinery, Approved Document K | Headroom over stair appears below 2.0 m. Investigate and correct. |
| Escape window does not open fully Windows & glazing, Approved Document B | Emergency escape window does not open to the required clear opening. Adjust hinges/restrictor. |
| Glazing in critical location not safety glass Windows & glazing, Approved Document K | Glazing in a critical location (low level or near doors) has no safety marking. Confirm or replace with safety glass. |
| Wall cabinet not secured Kitchen | Wall unit not securely fixed. Re-fix immediately. |
| Hot water too hot at bath (no TMV) Plumbing, Approved Document G | Bath hot water exceeds safe temperature; no thermostatic mixing valve. Fit TMV. |
| Flue terminal position unsafe Heating, Approved Document J | Flue terminal too close to an opening or boundary. Investigate and correct. |
| No RCD protection / RCD trips Electrical, BS 7671 | RCD protection absent or trips repeatedly. Investigate and rectify. |
| Faceplate loose / missing Electrical, BS 7671 | Socket or switch faceplate loose or missing, exposing terminals. Fix immediately. |
| Carbon monoxide alarm missing Electrical, Approved Document J | CO alarm not fitted in room with a fixed combustion appliance. Fit alarm. |
| External steps without handrail External, Approved Document K | External steps lack a handrail. Fit handrail. |
| Retaining / boundary wall unstable External | Retaining or boundary wall leaning or cracked. Investigate and make safe. |
| Integral garage door not fire rated / self-closing Garage, Approved Document B | Door between integral garage and house is not self-closing fire door. Correct. |
| Light fitting unsuitable for zone Bathroom, BS 7671 | Bathroom light fitting not rated for its zone (IP rating). Replace. |
| Glazed door not safety glass Doors & joinery, Approved Document K | Glazed panel in door not marked as safety glass. Replace. |
| Handrail missing / not continuous Stairs, Approved Document K | Handrail missing or not continuous for the full flight. Fit. |
| Newel post loose Stairs, NHBC Standards 6.6 | Newel post moves. Re-fix securely. |
| Spindle loose / missing Stairs, NHBC Standards 6.6 | Balustrade spindle loose or missing. Re-fix or replace. |
| Stair carpet / nosing loose Stairs, NHBC Standards 9.3 | Stair carpet or nosing loose: trip hazard. Re-fix. |
| Smoke alarms not interlinked Electrical, BS 5839-6 | Smoke and heat alarms do not sound together. Interlink. |
| Heat alarm missing in kitchen Electrical, BS 5839-6 | No heat alarm in the kitchen. Fit. |
| Earth bonding missing Electrical, BS 7671 | Main or supplementary bonding missing or not labelled. Install and test. |
About the references
188 of the entries point to a chapter of the NHBC Standards, which is the technical guidance builders follow for homes covered by an NHBC warranty. Others refer to the Approved Documents that go with the Building Regulations in England, or to British Standards such as BS 7671 for wiring. They are there so you can find the relevant guidance quickly. They aren’t compliance advice, and a reference next to a defect doesn’t mean the home has failed that standard, which is a judgement for a qualified inspector or the warranty provider.
Checking a home yourself
To find these defects on a walk-round, use the new build snagging checklist, then the handover checklist on the day you collect the keys. Landlords and letting agents recording the condition of a rental can use the inventory checklist. When you’re ready to write it up, SiteSnag turns each photo into a snag with this wording and builds the PDF report on your phone.
Questions
What is the difference between a snag and a defect?
People use the two words loosely. A snag usually means a finishing fault on a new build, such as a paint run or a door that catches, while a defect can be anything from that up to a structural problem. SiteSnag lets you call them snags, defects or issues, and the word you pick is used throughout the PDF report.
Can I use this list as a snagging checklist?
It works better as a reference for wording. For the walk-round itself, the new build snagging checklist puts the checks in room order, and this list helps you describe what you find.
Who fixes new build defects?
The developer is responsible for putting qualifying defects right during the builder’s warranty period, which is the first two years under NHBC’s Buildmark, on the terms of the warranty that came with the home. Report them in writing to the developer’s customer care team with photos, and keep a copy of what you sent and when.
Can I add my own defects to the list?
Yes. In the SiteSnag app you can edit any of the built-in descriptions and add your own, so the wording you use on every job is there when you start typing.