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.
Active movement
Active movement refers to subsidence that is current and will be causing issues and needs to be addressed.
Historic movement
Historic movement is when subsidence has caused problems in the past but has been addressed and stopped. This is less of an issue, but it I still good to be aware if your property has any historic movement.
How do you identify subsidence?
Knowing how to identify subsidence can help you catch it if your property is showing signs.
Cracks in walls
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.
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
Doors and windows sticking
You may notice the door or window frames getting stuck more frequently, because the shapes don’t fit together anymore.
Uneven floors
You may see that you have uneven tiles, that gaps may have appeared near the skirting boar, or that your floors appear to be sloping or sinking. If you notice this in your property is important to get this checked.
What if it’s not subsidence?
There may be other explanations for cracks and shifts in your property.
Settlement
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.
Heave
Ground heave is when there is an upward movement of the soils beneath a property. This is often due to the expansion of shrinkable soils, such as clay and silt, when they are wet.
Essentially, it is the opposite effect of subsidence as the foundations will be lifting rather than sinking.
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.
Subsidence prevention
There are ways to reduce the risk of subsidence:
- Remove and maintain any bushes or trees near to the property
- Keep on top of maintenance of gutters and drainage to avoid leaks and blocks
- Reinforce your house’s foundations
- Be aware of any changes in your property, do regular checks to catch any issues early
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.
Identifying subsidence FAQs
How much does subsidence devalue a property?
The amount your property will be devalued with the presence of subsidence will depend on the severity and how much it has impacted the building. Significant subsidence can devalue a property by around 20%.
Can you live in a property with subsidence?
Subsidence can affect the safety of a house, especially if it is severe. It can be unsafe to live in a house with significant subsidence.
Do you have to legally declare subsidence?
By law, you should always declare historic or current subsidence when selling your home. If you do not disclose this then you are at risk of being sued for misrepresentation of the house you are selling.
Are all cracks in my house signs of subsidence?
No, not all cracks in your house will be the result of subsidence. There are other ways that a house might have cracks in such as temperature changes, plaster shrinkage, and damp.