Extreme Heat Is Making London Homes Sink. Here's Why

London residents have reported cracks appearing across walls, doors getting stuck and windows becoming warped after a summer of extreme heat and dry weather.The unusual changes are linked to a growing problem known as subsidence, where the ground beneath buildings shifts or sinks, which is affecting London and other parts of southeast England. Unusually hot and dry weather is causing the soil to dry out, shrink and shift, leading to cracks and other damage to buildings.According to a spokesperson for the British Geological Survey, or BGS, “Subsidence is one of the most damaging geohazards in the UK today,” CNN reported. Experts warn that the problem could worsen as rising global temperatures lead to more frequent periods of extreme heat and dry weather.Why Are London Homes Sinking?London is built largely on clay soil, which expands when it absorbs water and shrinks when it becomes dry. During long periods of hot and dry weather, the soil loses moisture and contracts.When this shrinking happens unevenly beneath a building, it can cause the foundations to move, leading to cracks and other structural problems.Trees and plants can also add to the problem. During hot weather, their roots search deeper for water and can draw moisture from the soil around nearby buildings, causing the ground to dry out further.Older Homes Face Higher RiskOlder properties are particularly vulnerable because many have shallower foundations. More than half of London's homes were built before 1945, making a large number of properties potentially more exposed to subsidence.According to data cited from British insurance company Aviva, several parts of London could face possible or probable subsidence risks by 2030, including areas such as Kensington, Westminster and the City of London.The problem is also spreading beyond the capital. Experts say subsidence, once mainly associated with London and southeast England, is increasingly affecting other parts of the UK as temperatures rise and dry conditions become more frequent.Insurance Claims Rise After Hot SummersHot and dry summers often lead to a rise in subsidence-related insurance claims, said subsidence expert Bob Gibson, who is the director of Building & Structural Consultants. In 2025, the UK insurance industry paid a record $415 million for subsidence-related claims, according to the Association of British Insurers.The trend has continued this year. UK insurers paid more than $97 million in subsidence-related claims during the second quarter of 2026, while the average claim reached a record $27,000. According to Louise Clark, general insurance policy manager at the ABI, “Following the extremely hot and dry weather we saw over July and August this year, it's likely we'll see more subsidence claims over the coming months."Climate Change Adds To The RiskExperts warn that rising temperatures could make subsidence a bigger problem in the future. According to British Geological Survey data, more than 26% of properties in London could be affected by 2070 if global warming continues at roughly its current pace.Measures to reduce subsidence can include removing nearby trees and vegetation or installing barriers to prevent roots from affecting a home's foundations. In more serious cases, the foundations may need to be strengthened by adding concrete underneath. Subsidence may develop slowly, but it can cause serious structural damage, reduce property values and make homes difficult to sell.