New build house in London: era-typical defects and London-specific risks

What makes this property type distinctive

New builds in London face two distinctive constraints: London Clay subsidence (modern foundations are typically deeper and less susceptible than Victorian, but still managed via piled or raft solutions) and post-Grenfell fire safety (most central London new-builds are flats over 11m, requiring EWS1 status for mortgage). Cladding remediation contributions and rising service charges are the headline ongoing-cost flags.

Common defects to expect

These items are routine for the property type. Most are renegotiation items, not deal-breakers. The survey's job is to flag which apply to this specific property and which have already been addressed.

• Snagging items, ventilation commissioning, and developer fix list
• First-12-month settlement cracking and acoustic separation
• Drainage and external paving gradients
• Trees in proximity to foundations
• London's Victorian combined sewers cover roughly 70% of the city and were not designed for modern rainfall intensity.

What the survey should cover

• All era-typical survey items (see the era-specific guide for the full checklist)
• London-specific subsidence and geology context: BGS GeoSure rates clay shrink-swell susceptibility as high or very high across the majority of inner and outer London.
• London-specific flood layers: Thames Barrier closure frequency has increased decade-on-decade since the 1980s.
• Coal Authority CON29M typically not needed in London.

Which survey level to book

Snagging survey before completion is the most useful document on a London new build. RICS Level 2 or 3 has limited value on a property that isn't ageing yet.

For a deeper comparison see Level 2 vs Level 3 survey.

Construction-specific risks

New builds in London face two distinctive constraints: London Clay subsidence (modern foundations are typically deeper and less susceptible than Victorian, but still managed via piled or raft solutions) and post-Grenfell fire safety (most central London new-builds are flats over 11m, requiring EWS1 status for mortgage). Cladding remediation contributions and rising service charges are the headline ongoing-cost flags.

What to check before offering

• →Read the EPC and consider how a New build house performs thermally in London's climate
• →Confirm era-typical retrofits (cavity insulation, electrics, plumbing) are documented
• →Check London-specific risks: London's Victorian combined sewers cover roughly 70% of the city and were not designed for modern rainfall intensity
• →Coal Authority CON29M typically unnecessary

Use the full pre-offer checklist on the house buying checklist to combine these property-type checks with the standard pre-offer items.

Run the check on this address

A free preview pulls available flood, subsidence, EPC, building age and listed status signals for a UK address in about 15 seconds. The paid report adds the remaining checks, seller questions and a PDF.

Frequently asked questions