What is subsidence?
It's when the ground moves downwards, disturbing a building's foundations and causing structural damage. Drought is usually the culprit. Upward movement caused by excess water – known as heave – can be equally destructive.
All this talk of drought... should I be worried?
It depends where you live. Swathes of England are now officially in drought – only the northernmost counties, along with Wales and Scotland, are not at risk this year. The soil your house is built on is also important. Clay is particularly susceptible to both shrinkage and expansion.
How will I know if it's happening?
Look out for cracks in walls or doors and windows that stick. If a crack is wider at the top and you can slot in a 10p piece, tell your buildings insurer immediately. It will pay for action to stop the subsidence and repair damage. If you make a claim you'll have to pay an excess, typically £1,000 or more.
What if I've moved insurer?
An agreement sets out who picks up the claim in such cases. If you claim within eight weeks of switching, the previous insurer handles it. Between eight weeks and a year, responsibility is shared between old and new insurers. After a year, it's down to the new insurer.
Can I prevent subsidence?
You can try. Prune or remove vegetation close to your home. Check drains, pipes and guttering for leaks and blockages – escaped water washes soil away. And check out the Association of British Insurers fact sheet (www.abi.org.uk) which has useful advice on prevention.