Climate subsidence: what sellers and buyers need to know now
A new analysis from the British Geological Survey has highlighted a growing risk facing millions of UK homeowners: climate-related subsidence. As Britain experiences hotter, drier summers, the ground beneath properties can shrink and shift, dragging foundations down with it. For anyone buying, selling or owning a home, it's worth understanding what this means and whether your property might be affected.
The research identifies London, Essex, Kent and a corridor of land stretching from Oxford to the Wash as the most vulnerable areas. London's particular exposure comes down to two factors working together: the underlying geology is prone to shrink-swell movement, and the capital is forecast to experience more pronounced changes in rainfall and temperature over the coming decades. Add in London's high building density, and you have what scientists call a "double whammy".
What the forecasts actually show
The projections are sobering, but they're also conditional on future emissions scenarios. Under a low emissions pathway aligned with the Paris climate agreement, roughly 500,000 properties could be affected by 2070. Under a medium scenario that tracks closer to current global emissions trends, that figure rises to over 1.8 million properties.
In London specifically, the medium scenario suggests more than 26% of the capital's homes could be susceptible to shrink-swell subsidence by 2070. Highly populated areas like Camden, Islington and Barnet are among the most at-risk neighbourhoods.
To put this in context: in the first half of 2025 alone, subsidence-related insurance claims reached £153 million across the UK. That was before the full impact of last year's exceptionally warm spring and driest conditions in over 50 years had time to materialise.
How this affects property values and mortgages
Subsidence isn't just a physical problem for a building. It's a financial one. When a property is identified as having subsidence issues, its value typically falls significantly. More problematically, lenders become reluctant to offer mortgages until the problem has been resolved.
This creates a catch-22 for sellers. You can't easily sell if buyers can't get mortgages, and you can't get mortgages without addressing the subsidence. With current mortgage rates sitting at 6.6% for two-year fixes and 4.92% for five-year products, already stretched borrowers face even higher barriers to entry.
Fixing subsidence isn't cheap. The work involved might include underpinning foundations, replacing utility pipes, and removing problematic trees or vegetation. In severe cases, the engineering required can cost tens of thousands of pounds.
Signs of subsidence to watch for
If you own a home in one of the identified risk areas, familiarising yourself with the warning signs makes sense. Diagonal cracks appearing around window and door frames are a classic indicator. Sloping or uneven floors are another. You might also notice doors or windows that stick or won't close properly.
None of these signs necessarily means subsidence is happening right now, but they're worth taking seriously and getting surveyed if you spot them. A proper structural survey should identify whether movement is occurring and what's causing it.
What you can do about it
If you're thinking about selling in a high-risk area, a proactive approach pays dividends. Get a specialist survey done before you market the property. If minor subsidence is identified and addressed early, you'll have documentation showing the problem was managed. This is far more attractive to potential buyers and their lenders than a property sold with undisclosed issues.
For buyers, subsidence searches should be a standard part of your due diligence, especially in London, Essex, Kent or the east coast corridor. Your surveyor should flag any obvious signs, and asking whether the property has any history of subsidence claims or repairs is essential before you commit.
At the broader level, these findings suggest that property investors and homeowners in vulnerable areas should think about resilience. That might mean ensuring you've got comprehensive buildings insurance that covers subsidence, or understanding your legal position if issues emerge after purchase.
The research also underscores why mitigation measures matter. Urban planning that reduces hard surfaces, increases vegetation, and manages water drainage more effectively could all help reduce subsidence risk in the long term. These aren't just environmental luxuries; they're becoming practical necessities for protecting property assets.
The climate science here isn't speculative. The UK really did experience its warmest spring and driest conditions in over 50 years recently. More of that pattern is coming. Homeowners, sellers and buyers in at-risk areas can't ignore it, but they can be informed, prepared and proactive about managing the risk.