Following temperatures reaching 34°C and 35°C on consecutive days in May, insurers and modelling specialists warned that structural movement risk is becoming harder to predict, particularly across older properties and clay-rich regions.
Zurich UK chief claims officer James Nicholson said heat-related losses were increasingly becoming a more established feature of the UK claims landscape.
“Heat is no longer an outlier, it’s becoming part of the baseline risk profile in the UK,” Nicholson said.
Alison Williams, managing director at Prestige Underwriting, said the issue was becoming more significant within the non-standard property market, where homes are often older, more complex or built using specialist materials.
“Periods of prolonged heat and drought are becoming a growing concern for the property insurance market, particularly within the non-standard sector where properties are often older, more complex or built using non-standard materials,” Williams said. “These homes can be inherently more vulnerable to structural movement, subsidence and the wider impact of repeated extreme weather events.”
The pressure is extending beyond structural damage itself. Williams warned that repair inflation and restoration complexity were adding further strain to claims costs, particularly for specialist and heritage properties.
“The knock-on effect is not just the structural damage itself, but also the rising cost and complexity of repairs, especially where specialist materials or heritage restoration work is required,” she said.
“For non-standard properties, particularly thatched homes, inflationary pressures are often even more acute.”
The industry has faced periodic subsidence surge years for decades, particularly following major
heatwaves in 1976, 2003 and 2006. But recent losses have intensified concerns that extreme heat events are becoming both more frequent and more financially severe.
ABI figures showed insurers expected to pay £219 million in subsidence claims following the 2022 heatwave, with 18,000 claims made during the second half of the year alone. In 2025, domestic subsidence payouts reached a record £307 million following what the Met Office described as the UK’s hottest summer on record.
Head of subsidence at Claims Consortium Group, Steven Coxon said the market was already tracking conditions similar to those seen during the 2025 surge year.
“Since 2018 we have had three surge events (2018, 2022 and 2025) and based on current MORECS data there is the potential for us to see yet another surge event this year,” Coxon said.
“The ground at the start of 2026 was still significantly damaged because of the severe weather conditions in 2025 and due to continued dry/hot weather in 2026 we are tracking a very similar picture to that of 2025.”
Coxon warned that repeated surge events could have wider implications for insurer appetite and pricing.
“This may lead to insurers changing their underwriting philosophy when it comes to insuring properties within areas of subsidence risk,” he said.
The underwriting implications are becoming more pronounced across the market. Alfie Richardson, underwriting manager at Iprism, said prolonged periods of extreme heat were becoming “a more material property risk for the UK insurance market, particularly from a subsidence perspective.”
“Longer, hotter and drier summers inevitably lead to increased soil shrinkage, which in turn drives a significant rise in subsidence claims activity,” Richardson said.
Richardson said insurers are increasingly relying on geospatial modelling and postcode-level exposure data as repeated heat events begin influencing underwriting appetite and acceptance criteria.
“That is leading to more cautious underwriting approaches in higher risk areas, including increased subsidence excesses, tighter acceptance criteria and in some cases, exclusions for natural peril cover altogether.”
Nicholson said heat-related losses were also becoming more operationally complex for insurers because damage often develops progressively rather than as a sudden catastrophe event.
“We are seeing higher volumes and longer claim lifecycles, with some cases taking longer periods to fully resolve, particularly where monitoring is required,” he said.
For climate and subsidence specialists, the growing concern is not simply the frequency of heat events themselves, but the extent to which historic assumptions are becoming less reliable in a changing climate.
Tim Farewell, director at MapleSky Ltd, said subsidence “event years” were becoming increasingly common.
“When I started modelling subsidence over 20 years ago, subsidence ‘event years’ were relatively few and far between. They are now becoming more and more common, and the insurers I work with are taking notice.”
Farewell warned that subsidence models based solely on historic claims data were becoming less reliable as climate conditions changed.
While London and the southeast have traditionally been viewed as the UK’s main subsidence hotspots, Farewell warned drying soil conditions were beginning to affect a much broader range of regions.
“The key change is that more and more of the soils across the UK are now drying out to the point where subsidence starts to become an issue, even in areas with few previous claims,” he said.
Farewell said the shift was forcing insurers to rethink how subsidence exposure is modelled as historic claims patterns become less reliable predictors of future risk.
