London residents have reported cracks in walls, doors stuck in frames, and warped windows following a summer of extreme heat and dry weather. These changes are linked to subsidence, a geohazard where the ground beneath buildings shifts or sinks, affecting London and parts of southeast England. Unusually hot and dry conditions are causing soil to dry out, shrink, and shift, leading to structural damage.

Subsidence is one of the most damaging geohazards in the UK today, according to a British Geological Survey spokesperson, as reported by CNN. Experts warn that the problem could worsen with rising global temperatures and more frequent periods of extreme heat and dry weather. London, built largely on clay soil, experiences expansion when it absorbs water and contraction when it becomes dry. Prolonged hot and dry weather leads to soil moisture loss and contraction, causing uneven foundation movement and structural issues.

Trees and plants exacerbate the problem by drawing moisture from the soil around buildings during hot weather. Older homes, with shallower foundations, are particularly vulnerable. More than half of London's homes were built before 1945, making a significant portion potentially more exposed to subsidence. Data from British insurance company Aviva indicates that areas like Kensington, Westminster, and the City of London could face subsidence risks by 2030.

Insurance claims related to subsidence have risen following hot summers. Subsidence expert Bob Gibson, director of Building & Structural Consultants, noted that hot and dry summers often lead to an increase in such claims. In 2025, the UK insurance industry paid a record $415 million for subsidence-related claims, according to the Association of British Insurers. This trend continued in 2026, with UK insurers paying over $97 million in the second quarter, with an average claim reaching a record $27,000. Louise Clark, general insurance policy manager at the ABI, stated that the extreme heat and dry weather in July and August 2026 likely means more subsidence claims in the coming months.

Experts warn that rising temperatures could make subsidence a bigger problem in the future. British Geological Survey data suggests that over 26% of properties in London could be affected by 2070 if global warming continues at its current pace. Measures to mitigate subsidence include removing nearby trees and vegetation, installing barriers to prevent root damage, and strengthening foundations with concrete. Subsidence can cause serious structural damage, reduce property values, and make homes difficult to sell.

The situation highlights the growing impact of climate change on urban infrastructure, with subsidence becoming an increasingly pressing issue in London and beyond.