Home insurance: subsidence

What is subsidence?

Subsidence occurs when the foundation of your house collapses or sinks.

This is often caused by:

• soil, usually clay, shrinking and swelling because of the weather
• nearby trees and shrubs absorbing the moisture in the soil beneath your home
• leaking drains softening the ground under your home.

It can have consequences for the value of your property and can greatly increase the cost of your home insurance.

Here, we explain how to spot, prevent and insure for subsidence.

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What are the signs of subsidence?

Your property might be suffering from subsidence if you spot any of the following signs:

• sudden cracks in plaster and brickwork that are wider at the top than at the bottom
• doors and windows sticking for no reason
• rippling wallpaper that isn't caused by damp.

It's important to note that cracks can appear on walls for varying reasons, so spotting one might not be a cause for panic. Settlement – where a building settles under its own weight – can also cause cracks to appear on walls. This is often seen in newly built homes and extensions.

If a crack is caused by subsidence it will be:

• more than 3mm thick – often getting wider over time
• diagonal
• wider at the top than at the bottom
• visible from inside and outside your home
• close to doors and windows.

Is subsidence covered by home insurance?

Most home insurers cover subsidence damage as standard, albeit normally with an excess of £1,000.

Of the 75 buildings policies we examined, only three buildings policies potentially apply a lower subsidence excess. The Gold policies from Bank of Scotland, Halifax and Lloyds Bank each apply between £100 and £500.  

Most buildings insurance policies will cover subsidence to your house, but many won't cover adjoining areas such as patios, garden walls, driveways and swimming pools unless the main residence is also affected.

Subsidence cover is standard in most policies, but if your property has been previously affected you may find it more difficult to find insurers that will accept you as a customer.

If you can't find an insurer that will cover you on affordable terms, it may be worth trying a specialist broker.

The British Insurance Brokers' Association can provide further practical advice and can recommend a specialist if you suspect your property has subsidence.

• Find out more: best contents insurance. 

Is my home at risk of subsidence?

Factors that can affect your risk of subsidence include:

Clay soil

Properties built on clay soil are at great risk of experiencing subsidence. Clay soil can shrink, crack and shift during hot, dry weather, making the ground unstable and potentially causing the foundations of your property to sink.

Drought

Homes in drought-prone areas are particularly at risk of subsidence because the soil is much more likely to dry out.

Trees and shrubs

Trees and shrubs around your home can increase your risk of subsidence. Some species absorb a lot of water, which makes the soil much drier.

Old homes

Subsidence is more common in Victorian and Edwardian houses as their foundations are shallower than the current UK minimum of 1 metre. This makes them more susceptible to damage from any movements in the ground.

Leaking drains

Leaking drains and water mains can increase your risk of subsidence as they wash away or soften soil, causing it to compact under the weight of your property over time.

Underpinning

Properties that have had their foundations underpinned may have experienced subsidence previously and are therefore at a greater risk.

Can I reduce my risk of subsidence?

You can reduce your risk of subsidence by taking the following steps:

• Make sure you plant trees and shrubs at least 5-10 metres away from your property.
• Prune the branches on your trees regularly.
• Keep pipes and drainage systems well maintained to stop water leaking into the soil beneath your house.
• Check the surveyor's report for signs of subsidence before buying a new home.

We've put together a guide to the house surveys you can get when buying, including estimated costs, a sample report and the accreditations to look for.

• Find out more: best buildings insurance.

Subsidence: your questions answered

Can subsidence be fixed?

Subsidence is commonly fixed by underpinning, which is the process of strengthening the foundation of a property.

Most home insurance companies offer cover for subsidence-related damage, but it often comes with a large excess (around £1,000).

If your property has experienced subsidence, the risk of it happening again increases.

Which trees cause subsidence?

While all trees can put your home at risk of subsidence, some species are more likely to cause problems than others.

Trees with long, fine root structures, such as poplars, willows and oaks could dramatically increase your chances of subsidence.

• Find out more: do insurance companies pay out for flooding?

What is heave?

Heave occurs when the ground under a building becomes saturated with water and begins to swell – moving upwards and often sideways.

This can cause similar damage to subsidence and is often covered under the same insurance guidelines.

How do I make a claim?

No one wants to have to make a claim on their home insurance, but should you be affected by subsidence there are ways to make the process as smooth as possible.

Our making a home insurance claim guide tells you all you need to know about handling the claims process – and which home insurance companies stand out from the pack when the going gets tough.

How do I appeal an insurer's decision?

If you make a flood claim and you feel your insurer has treated you unfairly, don't be afraid to make a complaint. 

Speak to your insurer first, but if it isn't proving helpful (and you've exhausted the complaints process), take the matter up with the Financial Ombudsman.

• Find out more: how to refer a complaint to the Financial Ombudsman Service

Can subsidence be fixed without underpinning?

Subsidence can sometimes be fixed without underpinning. It depends on what's causing the issue. 

If trees are the problem, removing them might stabilise the soil. Additionally, fixing leaky drains could prevent subsidence from worsening. 

However, if these measures don't work,  the most common solution is underpinning the foundations. This means adding support beams or an extra layer of concrete to strengthen them. 

Even if subsidence hasn't returned after underpinning, you might still face higher insurance costs in the future. 

• Find out more: how to find cheap home insurance