A new subsidence risk map has been created to help UK homeowners identify the worst-affected areas as heatwaves drive up the risk of costly property damage. This week's heatwave could leave homeowners facing bills running into thousands of pounds, with the Met Office issuing a red warning for parts of the country as temperatures threaten to hit 40°C.
Subsidence Claims Hit Record Highs
The Association of British Insurers reported a record £307 million paid out on subsidence claims in 2025, with the average claim reaching close to £17,000. This surpasses the average payout on any other home insurance claim type, including theft, fire or flood. Uswitch home insurance experts revealed that subsidence has overtaken every other claim type to become the single largest payout in UK home insurance.
Leoni Moninska, Insurance Expert at Uswitch, said: "Subsidence is an area where homeowners can easily be caught out - both by the risk to their property and by the excess they'd face on a claim."
Areas at Highest Risk
The risk is far from equally distributed. One in 10 land zones across Britain sits on soil classified as a significant subsidence risk by the British Geological Survey, with the worst-affected belt stretching from Dorset up through London and the East into North Yorkshire. London Clay, the soil lying beneath much of the capital and the Home Counties, represents the highest-risk geology in the country.
A statement on the Uswitch website explains: "We mapped subsidence risk across Britain. The good news: most of it is fine. The unfortunate news: there is a thick band of land (from Dorset up through London, the East and into North Yorkshire) that sits on soil that shrinks when it's dry and swells when it's wet. That's subsidence. It's one of the most expensive claims you can make on your home insurance."
High Excess Costs for Homeowners
The sting lies in the excess. While most policies charge between £100 and £250 when a homeowner makes a routine claim, the excess on subsidence cover typically sits between £1,000 and £2,500 — roughly four to ten times higher, reports the Mirror. This disparity exists because subsidence claims are structural and costly to investigate, meaning homeowners face four-figure bills before their insurer contributes a penny.
Advice for Homeowners
Should you suspect subsidence, it is worth obtaining a chartered surveyor's assessment before contacting your insurer. Taking this step prevents the enquiry from being recorded on the Claims and Underwriting Exchange (CUE) database, which can impact future premiums even if the crack proves to be harmless.
Moninska advised: "If you spot a crack, photograph it and monitor it over a few months. If it's still changing, call a chartered surveyor for a diagnosis before involving your insurer. Use our subsidence risk map to check your area. If needed, make sure your home insurance policy includes subsidence cover, and find out what excess you'd face - so you know you're on the right policy for your home."
Uswitch advises that homeowners situated in areas categorised as 'Moderate' or 'Significant' risk should verify whether their home insurance policy covers subsidence. While the majority of policies do include this protection, the excess tends to be considerably higher than for other types of claim.
Warning Signs of Subsidence
Uswitch says subsidence happens gradually, so you won't wake up one morning and find half a wall missing. The earliest signs are subtle: diagonal cracks in walls, especially around door frames, window frames or where extensions meet the original house. Hairline cracks are normal in any home. The flag is when a crack is wider than 3mm (about the width of a pound coin's edge) and runs diagonally. Other signs include doors and windows that suddenly stick, cracks visible from inside and outside on the same wall, cracks that get wider in summer and narrower in winter, wallpaper rippling at the corners of door frames, and floors tilting noticeably, especially in extensions.
