Subsidence: What property owners need to know

Spring and summer 2026 brought prolonged periods of exceptionally hot and dry weather across many parts of the UK, following similar conditions in 2025.¹ These conditions can contribute to clay soil shrinkage and subsidence. Written in collaboration with McLarens, this article explains the signs property owners should look for and what to do if they are concerned. 

What is it?

Much of our built environment is constructed on clay soil, which can shrink in response to external factors including moisture removal by vegetation and heat.² There are other reasons for subsidence to occur, but attention in the hot and dry conditions has largely been on this type of movement.

As the soil shrinks, it can cause structures built on, or into it to move downward, causing distortion and cracks to develop.

What am I looking for?

Buildings will respond differently depending on their construction type and the soil on which they are built. Subsidence damage often takes the following forms:

• Stepped, diagonal cracking, often tapering wider toward the top
• Rucking of wallpaper, and disturbance to decorative finishes
• Sloping of floors and other level surfaces such as windowsills
• Distortion to door and window frames, causing difficulty in opening and closing them
• Separation cracking where distinct parts of buildings meet, particularly bay window projections and extensions
• Damage to underground services including drains and water supply pipework
• Disturbance to external surfaces including distortion and undulation

If you notice any new damage of this type, or a change to normal building characteristics, this may indicate recent movement caused by subsidence. Expert advice is needed, however, as similar issues can be experienced which are the result of other influences.

What should I do?

If you are concerned, contact your broker or insurer to ask for advice. They may ask for photographs of the damage, or for some additional information to help work out the best way to assist.

Insurers have specialist loss adjusters who can help with diagnosis and advise on how insurance policies can assist. Even if you are not sure about the damage and possible cause, your broker or insurer will be pleased to help and advise.

Should I worry?

It is exceedingly rare that subsidence caused by clay shrinkage will cause very serious structural damage making a building unsafe.³ Understandably, cracks and distortions can cause a great deal of anxiety, but in most cases the biggest concern is ensuring a building remains weatherproof.

What happens next?

The majority of such cases can be remedied by identifying and removing or controlling the cause.⁴ This can involve:

• Vegetation removal or reduction allowing rehydration and reinstating soil volume naturally
• Repairs to drainage
• Repair to the building structure, including crack repair, reinforcement and cosmetic reinstatement

Substructure reinforcement, such as underpinning, grout injection or piling, is usually a last resort and avoided unless it becomes necessary.⁴

This can take time, and it is usual for subsidence claims to take many months, and sometimes longer, to resolve, including periods of monitoring and observation.⁵ If there are complicating factors, resolution can require patience.

Our Private Clients team and partners are here to assist if you are concerned. It is always best to notify us of any new cracking or distortion so we can give the best advice. Contact the team on 01635 245638 or at privateclients@specialistrisk.com.

Policyholders can also find some useful information and extra detail here: What to do if subsidence occurs.

Sources

1. Met Office, Summer 2026 provisionally hottest on record for the UK (1 September 2026); Summer 2026 so far: a look at the season at the halfway point (16 July 2026); Summer 2025 is the warmest on record for the UK.
2. British Geological Survey, Swelling and shrinking soils; GeoClimate Shrink–Swell.
3. McLarens; Royal Institution of Chartered Surveyors (RICS), Subsidence consumer guide.
4. Association of British Insurers (ABI), What to do if subsidence happens; RICS, Subsidence consumer guide.
5. Financial Ombudsman Service, Subsidence and other types of ground movement; RICS, Subsidence consumer guide.