Are the Recent Heatwaves Putting Your Home at Risk?

We've had three heatwaves this year already, and the ground's noticed. Anyone who's owned a property through a proper dry summer knows what tends to follow. Doors that suddenly stick. Hairline cracks that weren't there in spring. A phone call to the insurer that nobody wants to make.

Subsidence isn't rare in the UK. But it does come in waves, and this looks like one of them.

What's actually happening

Insurers paid out a record £307 million in subsidence claims in 2025, the highest figure on record. That followed the UK's hottest summer, and now 2026 is tracking a similar pattern, with a third heatwave and the longest dry spell central England has seen since 1996.

Why this matters if you're buying or already own a house

If you're buying, this is exactly the kind of risk a viewing won't show you. A house can look completely fine on a warm July afternoon and still be sitting on ground that's actively shrinking beneath it.

If you already own your home, the risk is just as real, but the warning signs are often dismissed as normal wear and tear. A door that's started sticking gets blamed on humidity. A crack gets filled and painted over without anyone asking why it appeared.

Subsidence repairs aren't cheap. Underpinning alone can run into tens of thousands of pounds, and that's before you factor in the disruption of living through the work, or the impact on the property's value and future insurability.

The warning signs worth taking seriously

Not every crack means subsidence. Most don't. But certain signs are worth getting checked rather than ignored:

• Cracks wider than 3mm, particularly if they're diagonal and run through brickwork rather than just plaster

• Cracks that appear suddenly, especially after a dry spell, rather than developing slowly over years

• Doors and windows that have started sticking without an obvious cause

• Cracks around door and window frames, where the frame has pulled slightly away from the wall

• Visible tilting or leaning, even slight, in a wall or extension

  
  

If you're spotting one or two of these and you're not sure whether it's cosmetic or something more serious, that's exactly what a structural inspection is for. It's a much better use of your money than guessing.

Why buyers need to think about this before they view a house, not after

Buying a house that turns out to have subsidence isn't just expensive. It can also make the property harder to insure and harder to sell on again in future.

This is where a survey earns its money twice over. First, by catching structural movement before you're legally committed. Second, by giving you the evidence to renegotiate the price, ask the seller to fix it, or walk away entirely if the movement's serious.

Older properties, particularly those built before the 1980s, are more exposed simply because they've had more time and more dry summers to be affected. Homes with large trees nearby are also higher risk, since tree roots draw moisture from the surrounding soil and accelerate the shrinkage. A Level 3 Building Survey is the right level of detail for this kind of property, especially in a year like this one.

What a surveyor is actually looking for

A trained eye picks up on things most buyers walk straight past. Cracking patterns that suggest movement rather than settlement. The age and direction of cracks. Whether nearby trees are close enough to be a factor. Signs of previous, undisclosed repair work that's been painted over rather than properly addressed.

This is also where damp gets flagged alongside structural concerns, since the two often turn up together in older housing stock. If a damp and timber survey is recommended alongside a structural check, it's usually because the two issues are connected rather than coincidental.

What to do if you're worried about your current home

If you own a property and you're seeing some of these signs, don't wait for it to get worse before doing anything. Movement tends to be far cheaper to monitor and manage early than to fix once it's advanced.

A structural inspection will tell you whether what you're seeing is genuine subsidence, historic movement that's already stabilised, or simply normal seasonal cracking that isn't cause for concern. That distinction matters enormously, both for your peace of mind and for any conversation you might need to have with your insurer.

A grounded final word

Not every crack is a crisis, and not every dry summer causes damage. But three heatwaves in one year is enough to take seriously, and the data backs that up. Claims are rising, and more of the country is exposed to this risk than it used to be.

Whether you're buying a house this summer or you've noticed something concerning in the one you already own, it's worth getting a professional opinion rather than hoping it settles down on its own. If you'd like a Level 3 Building Survey or a dedicated structural inspection, get in touch with our RICS surveyors or get an instant quote. We'll give you a straight answer, not a scare story.

FAQs

Is subsidence common in the UK? 

It's more common than most people realise, and claims tend to spike sharply after hot, dry summers. 2025 saw a record payout year, and 2026 is following a similar pattern.

How do I know if cracks in my house are subsidence or just normal?

Width, direction and speed of appearance all matter. Cracks wider than 3mm, running diagonally, or appearing suddenly after dry weather are worth having checked. A structural inspection will give you a clear answer either way.

Does subsidence affect house prices?

Yes, significantly. A confirmed history of subsidence can affect both the sale price and future insurability of a property, which is exactly why buyers use survey findings to negotiate.

Which UK areas are most at risk of subsidence?

London, the South East and the East of England have the highest concentration of clay-rich soil, but drying conditions mean more regions across the UK are now becoming exposed to the same risk.

Can trees near my house cause subsidence?

Yes. Large trees close to a property draw moisture from the surrounding soil, which can accelerate clay shrinkage and increase the risk of ground movement.

What survey do I need if I'm worried about subsidence?

A Level 3 Building Survey or a standalone structural inspection is the right choice, particularly for older properties or homes near large trees.

Will my home insurance still cover subsidence?

Coverage varies by insurer and postcode, and some insurers are tightening their criteria in higher-risk areas. It's worth checking your policy directly, but getting an independent structural assessment first puts you in a stronger position either way.

How much does underpinning cost? 

Costs vary hugely depending on the extent of the damage, but underpinning work can run into tens of thousands of pounds, which is why early identification matters so much.

We've written this blog to help you better understand property-related topics. While we aim to keep the information accurate and up to date, every property is unique, so we'd always recommend speaking to a qualified surveyor for advice specific to your situation.