What is subsidence?
Subsidence is the downward movement of the ground due to loss of water in the foundations. This can be caused by the type of soil the property is built on, tree roots sucking up moisture or long periods of dry weather.
As the ground changes, the levels of the property can drop, causing instability, cracks and other issues.
The damage caused by subsidence can vary from a small inconvenience to a huge structural problem.
How do you identify subsidence?
You’ll often notice subsidence in a property when there are lots of cracks in the internal walls and external brickwork. These could be small cracks getting bigger, or new ones appearing.
You may also notice the door or window frames sticking more frequently, because the shapes don’t fit together anymore.
Subsidence can often be identified by cracks that are:
• Particularly near doors or windows
• Diagonal and wider at the top
• Visible both inside and outside the home
What if it’s not subsidence?
A similar situation to subsidence is ‘settlement’.
Settlement is also the dropping of the ground underneath a property, but whereas subsidence is due to the soil, settlement is due to the weight of the house compressing the ground beneath. Settlement is considered within 10 years of the property being built, and the distinction is important, because insurance often won’t cover settlement.
How do you fix subsidence?
Subsidence doesn’t have to be a cause for concern – often it’s covered by your building insurance, and can sometimes be minimal.
If your subsidence is caused by tree roots, for example, removal of the roots and fixing the ground should solve the problem. Similarly, if the ground has dropped due to drainage issues from a leaking pipe, it’s a quick fix.
Bigger subsidence issues can need foundation underpinning, which is intensive and can be incredibly expensive. RICS say that less than 10% of properties with subsidence need underpinning, so it’s not something to be hugely worried about.
Should I buy a house with subsidence?
Finding that your dream home has subsidence issues doesn’t mean it’s the end of the journey. Ensure you get a qualified, experienced Chartered Surveyor to carry out a Building Survey for you. This in depth structural survey will give you a better idea of whether the property has subsidence, or is likely to, and what you can do about it.
If the property has previously had subsidence and has been treated, your sellers should have the appropriate paperwork.
This will include a Completion Certificate, issued by the council if underpinning work has been carried out, and a Certificate of Structural Adequacy from the Building Surveyor, if it was done as part of an insurance claim.
Your conveyancing solicitor will also be able to learn more about the nature of the ground around the property from the searches, but it’s always worth talking to a surveyor if you are concerned.
Updated August 2022 by Andi Forsythe