Londoners are facing historic levels of subsidence risk after five successive heatwaves dried out the clay soil on which much of the British capital is built.

Insurance claims tied to subsidence – a phenomenon associated with bouts of hot, dry weather that shrink the soil and destabilise the foundations on which buildings stand – hit a record last quarter, according to data provided by the Association of British Insurers (ABI). On average, households claimed £20,000 (US$27,200) for the risk, more than in any previous quarter and a 15 per cent jump from the same period in 2025, the ABI said.

Laura Hughes, head of general insurance at the ABI, said the upwards trend is likely to continue. “We expect to see more subsidence cases because of the hot weather,” she said in an interview.

Londoners have taken to social media to express their dismay. On Reddit, people offered personal accounts telling of “horrendous cracking” in their homes, and “doors sticking” due to subsidence. One said it was “genuinely scary” to discover that their kitchen had moved as the foundations of the home shifted.

Another Reddit user described the response of a structural engineer they contacted for help. “Before I could finish explaining he laughed and said, ‘You and 20,000 other people in southeast London’,” the person wrote.

“It’s crazy, what’s happening now,” said Otso Lahtinen, chief executive of Geobear, an engineering firm that is regularly called in to repair damage caused by subsidence. “It’s the new norm, and it seems it will happen more often in the next 20 to 30 years.”