UK’s biggest insurer hit by rise in subsidence claims after record hot summer

Increase reported by Aviva after Hastings Direct said claims were up 140% in August and Axa said it had been a ‘surge year’

The UK’s largest insurer has been hit by a rise in subsidence claims after an extremely hot summer left households across the country grappling with the fallout from the growing climate crisis.

Aviva said on Friday it had experienced the jump amid an industry-wide surge in households filing subsidence claims with their insurers to cover repairs, which typically are needed to address cracks, sloping floors, and off-kilter doors and windows.

It follows two record hot summers in the UK; August this year was the joint hottest month ever recorded around the world. Drier summers cause the ground under houses to shrink, which undermines a property’s foundations. It then expands in wetter winters, which can further damage homes.

Aviva experienced a “peak subsidence period” between July and September, with claims continuing into October, its chief executive, Amanda Blanc, told Bloomberg in an interview on Friday. Aviva would not provide any further detail on the scale of the increase in claims.

Blanc said homeowners could reduce the risk of subsidence by keeping a close eye on drains, pipes and gutters, and fixing any leaks that could affect the ground under homes. “It’s about managing trees and plumbing,” she said.

A number of fellow insurers have also experienced a rise in claims in recent months. Hastings Direct said it received record subsidence claims in August, up 140% compared with a year earlier. Axa, one of the UK’s biggest home insurers, has said it has been a “surge year” for subsidence.

The value of claims have also hit a record high. The average subsidence claim in the UK hit a high of £20,000 between April and June, more than £2,000 higher than a year earlier, according to the Association of British Insurers. Insurers paid out £72m for domestic subsidence claims, compared with £60m in the same period last year.

Millions of homes are at risk of subsidence because of the worsening climate crisis, according to the British Geological Survey, which estimates that up to 11% of UK homes – more than 4.2m houses – could be at risk by 2070. Older properties with shallow foundations and those built on clay-rich soil are facing the biggest threat, with areas including London, Essex, Kent and areas around Oxford among the most vulnerable.

But despite the rise in subsidence claims, Blanc said Aviva was in rude health, having reported a 19% rise in general insurance premiums to £11.8bn in the third quarter.

“Aviva is in great shape,” she said in a statement released alongside the company’s financial results. “Our performance has been excellent in the first nine months of 2026, demonstrating once again the benefits of scale across our diversified business. We continue to deliver strong, profitable growth, particularly in the capital-light areas of general insurance and wealth.”