Should I buy a house with cracks or subsidence?

4 November 2026 · Blog · Buying a home

Almost every older house in London has cracks somewhere. The real question isn’t whether there are cracks, but what caused them, whether they’re still moving, and what it would cost to put right.

Cracks that are usually nothing to worry about
• Fine hairline cracks in plaster, especially at ceiling junctions and around doors
• Cracks in new plaster or new extensions as the materials dry out and settle
• Old, stable cracks that have been filled and haven’t reopened

Cracks that need a closer look
• Diagonal cracks above doors and windows, which can point to failing lintels or foundation movement
• Cracks that are wider at one end than the other, or more than about 3mm wide
• Cracks that open in summer and close in winter, often a sign of clay shrinkage near trees
• Cracks where an extension or bay window joins the main house
• Doors and windows that stick, or floors that slope

What “subsidence” actually means
Subsidence is when the ground beneath a building moves downwards, taking the foundations with it. In London, the usual causes are trees drying out the London Clay in summer, and leaking drains washing away or softening the ground. It’s different from heave, where clay swells, and from settlement, which is the normal bedding-in of a new building. Subsidence, heave or settlement? →

So, should you buy it?
Often, yes. Many houses with past subsidence have been properly repaired and are perfectly sound. What matters is knowing:
• whether the movement is historic or still active
• what caused it, and whether the cause has been dealt with
• whether any past repairs, such as underpinning, were done properly and signed off
• whether you can get buildings insurance at a reasonable price, which your solicitor and broker can check

How we help
We inspect the cracking, look at nearby trees, drains and past repairs, and give you a clear view of the cause and what’s needed. If the report shows work is required, you can use it to renegotiate the price before you exchange. Subsidence and crack reports →

Book a pre-purchase structural report →
Site visit within 3 working days · report within 48 hours · get in touch or call 020 3835 2633

More for home buyers
• My RICS survey says “refer to a structural engineer”
• Buying a house where a wall was removed without approval
• Is movement normal in a Victorian terrace?
• My lender wants a structural engineer’s report
• How quickly can I get a structural report before exchange?
Structural surveys in London →
Structural engineer or RICS surveyor? →