Soaring temperatures and prolonged dry spells have led to a rise in subsidence claims, but what is it and what can you do to take care of your home?
What is subsidence?
Subsidence is the downward movement of the ground beneath a property, causing foundations to sink. This can lead to structural damage, which could impact the value and safety of your home.
According to the Association of British Insurers, the risk of subsidence to UK homes is increasing as prolonged dry spells and record-breaking heatwaves, like the one in Spring 2025, can cause clay soils to shrink, which can lead to subsidence.
Common causes of subsidence
- Clay soil shrinking or swelling
Clay is one of the most common soil types in the UK, and it’s particularly prone to subsidence. Clay soils shrink and swell depending on their moisture content, meaning they can easily be affected by long, dry spells – such as the UK’s recent heatwave summer.
- Tree roots
Trees and shrubs also draw the water from the soil, causing it to shrink. Once again, this is a particular problem in extended hot weather, as the parched plants push their roots under or through foundations in search of water.
- Leaking drains or pipework
Another common cause could be leaking drains or pipes, which can soften or wash away the ground beneath the house, particularly if the soil has a high sand or gravel content.
- Poor ground preparation
Extensions may be more vulnerable to subsidence, especially if the ground wasn’t assessed properly or the foundations were poorly built. The age of a house can also be a factor, as Victorian and Edwardian homes tend to have more shallow foundations.
Possible signs of subsidence
Although cracks are often thought to be a clear sign of subsidence, you shouldn’t panic at the first sight of one. It’s not uncommon to find fine cracks in the plastered walls of new properties (as the building settles under its own weight) and changes in temperature can cause minor cracks where walls and ceilings meet.
If visible cracks appear suddenly in a particular area of the house, they'll need further investigation. Cracks wider than 3mm, roughly the depth of a £1 coin, and those that appear suddenly, diagonally, and are wider at the top than the bottom, are more likely to indicate subsidence.
Other things to look out for include:
- Doors and windows that stick (due to the distortion of the building).
- Gaps between walls, ceilings, and skirting boards.
- Rippling wallpaper that isn’t caused by damp.
- Cracks at the join of an extension and the main building – as this could mean it’s pulling away from the house.
- Sloping or uneven floors – this could be a sign that the foundations are unstable.
What to do if you suspect subsidence
If you suspect your property may be affected by subsidence and you have buildings insurance, call your insurer to find out more. Depending on your policy, many insurers will appoint their own loss adjusters and surveyors to investigate and manage repairs.
Alternatively, you may want to seek independent advice. This will involve calls to various experts, such as a structural engineer, a RICS-accredited surveyor or a tree surgeon who can assess the damage, confirm the cause of the problem and recommend next steps.
How to fix subsidence
Solving the problem depends on what’s causing it.
Trees may need to be pruned or removed or drains and brickwork repaired. Resin injections may be an option to stabilise the soil by injecting an expanding resin solution that can raise, re-support and re-level the foundations beneath the property with minimum disruption.
In extreme cases, the solution may involve underpinning the property while the foundations are strengthened. This is a costly and time-consuming solution that may involve alternative accommodation while the work is done. Fortunately, it’s quite rare with the Royal Institute of Chartered Surveyors (RICS) suggesting it’s only needed in less than 5% of affected homes.
How to prevent subsidence
There are steps you can take to try and avoid such problems from occurring in the first place.
- Check drains, pipes and gutters for blockages, splits and leaks.
- Prune shrubs and trees regularly and plant any new ones well away from your house.
- Make sure you assess land stability before building an extension or carrying out any renovations.
If you’re concerned about subsidence, The British Geological Survey now offers postcode-level subsidence risk scores.
These can help homeowners understand their property's vulnerability based on soil type, foundation depth, drainage, and proximity to trees.
Don’t ignore signs of subsidence
The one thing you shouldn't do when you notice potential subsidence is ignore it.
Failure to act fast can lead to further damage and more expensive repairs. If you’re at all worried, contact your home insurer or call in the experts as soon as possible.
