Read an interactive and user-friendly version of this guide below.
Damage caused by subsidence can be expensive to fix. In fact, at Total Landlord our most expensive claim ever for subsidence damage was for an eyewatering £348,703. The good news is that subsidence claims have dropped since then. They are our sixth most common type of claim and over the last five years (up to 2023), the highest claim has been for just over £30,000. And our average claim size for subsidence is cheaper than you might think, at £7,385, based on the last five years’ claims.
The key thing with subsidence is to take action right away. It can be tempting to put off dealing with it, but the longer you leave it, the more expensive your repairs will probably be.
To help you make the right decisions, we’ve rounded up everything you need to know about subsidence.
Subsidence is when the ground beneath a property sinks, pulling the property’s foundations down with it.
This process can cause the walls and floors to shift, leading to cracks and potentially destabilising the construction of the property.
Subsidence can be caused by a range of things including clay shrinkage, trees growing close to the foundations, water washing away soil beneath the property, used or disused mines, formation of underground caverns and poor foundations.
Subsidence claims tend to come to light after extremely dry or wet spells, especially when they are due to soil types. This could be why we see a spike in subsidence claims during autumn.
Warmer weather is one of the most common causes of subsidence. In fact, subsidence claims increased by 20% in 2018 because of the UK’s heatwave.
As the ground below a property warms, clay-rich soil can shrink as the water trapped in it evaporates. This causes the soil to shrink, leading to the downward movement of the ground above.
Trees may look harmless enough, but they can cause subsidence in two different ways.
Drawing water out of the soil can cause that soil to shrink – and a mature oak tree can draw up to 1,000 litres per day! Trees growing near to or under the foundations can also cause the ground to shift and become less stable.
Leaking drains, escape of water, flooding and heavy rainfall can wash away soil particles over time, causing the ground to slowly shift or become less stable.
Older properties often have shallower foundations than new builds. The use of the wrong materials in the foundations or not properly preparing the earth can also lead to foundations shifting below the property in new developments as well.
Subsidence is just one of the types of ground movement beneath a property, but there are others including settlement, heave and landslip.
Settlement and subsidence are often confused. It’s important to understand the difference between the two, because some insurers will cover subsidence but not settlement.
Total Landlord, for example, does not cover the normal settlement, shrinkage or bedding down of new structure or the settlement or shrinkage of made up ground or of materials brought to the site.
Settlement occurs when the ground below a property is compacted by the weight of the building. This usually happens in the first 10 years after building and is relatively common. Cracks in the walls caused by settlement are usually harmless and can be plastered over.
However, cracks that appear and continue to grow, reaching a width of 15mm or more, should be investigated to make sure that the property is structurally sound.
Heave is essentially subsidence in reverse. The ground below your foundations moves upwards, causing the foundations, walls and floors to shift.
The most common cause of heave is when the soil beneath the house becomes saturated with water that has no way to escape – often because a mature tree near the property has been removed or died. This causes the soil to expand, pushing the foundations upwards or sideways.
Subsidence is down, heave is up – so what is landslip?
Landslip is the sideways movement of the ground beneath a property, often the result of soil erosion or the property being built upon or near to a slope.
Since you can’t see what’s going on below ground, the evidence of subsidence is usually found in the property itself, most often as cracks in the walls.
Don’t worry, not all cracks are signs of subsidence. Most cracks in the walls are harmless and perfectly normal.
Cracks caused by subsidence tend to have a few noticeable characteristics. Here are a few questions that will help you tell if your cracks are caused by subsidence.
If the answer to any of these questions is yes, it may be worth getting an expert to assess whether subsidence is an issue.
Wallpapers can start to wrinkle or crease because of condensation, but it can also happen because of subsidence.
A good way to test whether the ripples are the result of dampness is to check the windows for signs of condensation first thing in the morning. If there’s no condensation, it might be a sign of subsidence.
Cracks caused by subsidence often appear near to doors and windows. If your doors and windows no longer fit or are tighter than they used to be, that may be a sign of subsidence.
In most cases, subsidence happens slowly. Because of this, it can be tempting to put off dealing with it or to convince yourself that there isn’t really a problem at all. Unfortunately, this can create more problems in the long run.
Properties with a history of subsidence are often harder to sell, which means that you’ll have to sell at a lower price.
It’s expected that people who are selling a property with a history of subsidence are honest with their letting agents and potential buyers. It’s likely that any buyers will ask for as much documentation and information as you can give them.
Don’t try to cover subsidence up. Most buyers will conduct a survey before handing over any money, which will reveal the subsidence. At this point it’s likely they’ll either pull out of the deal altogether or ask for a dramatically reduced price.
Similarly, most renters won’t want to live in a property which doesn’t feel secure, which may mean that you have to put your property on the rental market at a lower price.
If subsidence isn’t addressed in the long term then there is a risk of serious structural damage and even collapse.
As is often the case, the cost of preventing this kind of damage will probably be lower than the cost of repairing it.
Most insurers charge higher premiums to cover properties with a history of subsidence because there’s a higher chance of damage claims.
Thankfully, there are steps that you can take to understand whether you’re at risk and to mitigate that risk if you are.
Some properties will be more at risk than others. Here are a few questions that will help you understand whether your property might be affected by subsidence:
If you answered yes to any of these questions, then there is a chance (but by no means a guarantee) that your property could be affected.
Here are a few things you can do to reduce the likelihood of this happening.
You should avoid planting trees too close to your property. We recommend that you plant any trees or shrubs as far away from your property as the expected height of the fully-grown plant.
If you already have a tree or trees that are close enough to pose a risk, don’t rush into having them removed. Removing the roots can lead to instability and water-logging, creating the ideal conditions for subsidence!
Instead of removing it, make sure that the tree is regularly pruned back to prevent the roots from growing too deep or too far to cause damage. You should speak to a tree surgeon to help you decide on the best way to do this.
The ground beneath your house can become water-logged because of rain or flooding, but it can also be caused by leakage and water escape. Have your guttering and plumbing checked once a year to make sure that the ground isn’t becoming saturated from a leak.
Always follow building regulations
This should go without saying, but if you’re having building work done, always comply with regulations. Extensions in particular are a risk factor for subsidence, so make sure your builders are doing everything they’re supposed to.
If you think you have a subsidence problem, the first thing you should do is contact your insurer. They will be able to advise on what to do next, but the next step will probably be to contact a chartered surveyor who will help you identify the cause. More on this in the section on subsidence claims, but here are some of the solutions they might suggest.
If the subsidence is being caused by a tree, a tree surgeon will be able to advise on the best course of action, whether that’s removing the tree itself or pruning it back to manage its growth.
If water is escaping from your property or the water mains, you’ll need to contact a plumber to fix the leak.
You should then monitor whether the symptoms of subsidence (such as cracks in the wall) continue or stop.
Underpinning is the most extreme and expensive course of action. As a result, it’s normally the last resort. Underpinning is when you excavate the ground beneath your property and replace it with materials that are less likely to subside.
Unfortunately, there’s no guarantee that underpinning will fix the problem altogether and you may still struggle to sell or insure the property after the work has been carried out.
But if your property requires underpinning it’s still much better to bite the bullet than to do nothing.
Is there any reassurance for fretting sellers, or potentially any reward for buyers willing to take a punt on a property affected by subsidence?
For owners of houses with a history of subsidence, the anxiety over what happens when you come to sell it—and the process of doing so—can be overwhelming. For prospective buyers looking to rent the property out, doing your homework will help you decide whether it is worth the punt. And for more information you can download our infographic on buying, selling and letting a property with a history of subsidence.
For prospective buyers, subsidence properties can sometimes work in a landlord’s favour. Most buyers will be put off by evidence of subsidence, particularly if they are unwilling to do the research to understand the exact cause of the subsidence.
The complications associated with subsidence can bring the price of a property down by as much as 20%. But remember, that saving comes with some serious risks attached.
Whether you decide to risk it or not, you should always ask for as much information as possible from the estate agent and the sellers.
Ask for documentation on the repairs that were conducted, as well as an engineer’s report if possible. You could also get a speculative insurance quote to see whether there are any premiums attached to the area.
Speaking with the current owner of the property often gives you the best indication of the situation. You should, however, only use this as the basis of your research. Despite what you may feel, you should always seek a professional opinion using evidence-based means to determine the true state of the subsidence. This will also help to give an indication of how the situation can be rectified.
If you decide to go ahead, always pay for a structural engineer’s full survey of the property to make sure that it’s sound. Though time-consuming, a full structural survey provides a comprehensive report of the property’s condition and requirements, including any issues involving subsidence. In fact, some mortgage-lenders may require such a report as mandatory for properties with known issues of subsidence.
“If you are looking to buy a property to rent, it’s always best to have a homebuyers survey carried out to assess the risk of subsidence so that you know what you are getting into. If the survey uncovers a subsidence issue, then we would strongly recommend commissioning a structural engineer’s report to understand the full extent of the problem. We also advise that you contact your insurer to understand whether they can cover the property.”
Steve Barnes, Head of Broking, Total Landlord
Unfortunately, some renters won’t want to live in a property with a history of subsidence.
Those that are happy to will probably want some kind of guarantee that they will be safe, such as evidence of corrective work. They may also use the subsidence to negotiate down the rental price of the property.
As we’ve already mentioned, selling a property with a history of subsidence can be challenging. The best way to improve your chances is to collate any documentation that you have to reassure the buyer that the property is structurally sound and not to try and deceive them if that’s not the case. Collating this documentation provides evidence of the exact history of the property and will give confidence to the buyer that you as the seller have done all that you can to control the situation.
When the time comes to selling your subsidence property, honesty is the best policy. You should never try to hide the subsidence as it will only put off potential buyers when, not if, they realise the property is affected. In fact, showing you are proactive in dealing with the issue responsibly gives you a much better chance of selling.
This varies from insurer to insurer, but at Total Landlord, we will cover properties with subsidence issues.
However, like any insurer, we will need all the information relating to the problem so that we can price it into our cover.
Does insurance pay out for subsidence?
We’ve mentioned that the average claim amount over the last five years is currently £7,385, with the highest claim being for £30,096. This is a significant drop compared to a couple of years ago, when it was £11,423 and the highest claim was £71,800. Our largest subsidence claim ever – the eyewatering £348,703 – dated back to 2009 so is not included in these figures. This illustrates how complicated the claims process can be for subsidence claims and how long it can take. The reason this claim was so high is that the only way to deal with the issue was to knock the property down, redo the entire foundations and start the rebuild from scratch.
Over the past five years the number of subsidence claims we’ve received at Total Landlord has actually decreased slightly:
Total Landlord subsidence claims broken down by year:
2019 - 46
2020 - 36
2021 - 24
2022 - 33
2023 – 17 (at the mid-way point)
These claims can be broken down into the following causes:
Tree roots - 9
Foundations – 57
Drains – 13
Clay soils - 67
Other - 10
Watch this video with Steve Barnes, Head of Broking at Total Landlord, who explains some of the main causes of subsidence, what to do if you spot it, how you can prevent it and how insurance can help should you be affected.
A comprehensive landlord insurance policy such a Total Landlord policy, will cover all of the costs to repair the building. For example, in one case, a policyholder was awarded a total of £37,000 for repairs to the porch and main building for damage caused by subsidence. In this case, because the property was unsafe, the tenants had to move out. Fortunately, under their Premier policy, the policy holder was also covered for loss of rent.
The claims team at Total Landlord point out that structural cracks can also occur as a result of movement to the property for reasons that are not classified as subsidence, for example, lateral or thermal movement, general settlement, roof spread of a property and lintel failure. These are not considered under subsidence on an insurance policy.
Subsidence claims are complex matters which can take years to resolve. With most insurance claims, the process is straightforward - damage has occurred, you fix the issue and arrange for remedial works or replacement items. With subsidence issues, claims are a lot more involved. Here, Emma Bracchi, Senior Claims Technician at Total Landlord, explains the process of a subsidence insurance claim.
To start the claim process, insurers like to see a report from a builder or a surveyor confirming, in their professional opinion, what the cause of the cracking is from. We need to establish if the property is in a high subsidence area, and also the age of the building and if any refurbishment works have been recently carried out. All buildings have natural movement, and when a property is newly built, the property needs to ‘bed’ in. This is why new builds often have a review period by constructors at the 12 and 24 month period - this is to allow the property to bed in.
Once a report is received confirming the property is suffering from movement, a specialised adjuster is appointed, and a series of tests are done at the property. This is usually done with bore holes around the property to see what type of soil the ground is made up from. As we’ve mentioned already, there are many factors that could cause subsidence, for example:
Once the cause is established, the adjuster will approve for the cause of the issue to be rectified and then the contentious monitoring ny remedial works to the property are carried out. If there are extremely large cracks, an interim repair can be made for cosmetic and safety purposes, but the final repair will only be done once the monitoring process is complete. The reasoning behind this is that the insurers/adjuster need to make sure the property is stable, so by carrying out an inspection after each yearly season, they can monitor whether the property is now stable. Tests need to be carried out after wet and dry seasons to make sure the ground is stable.
If you need to make a claim for subsidence, you should:
If you’re concerned about subsidence affecting your rental property, our team can help. A comprehensive policy such as Total Landlord’s Essential and Premier policies will cover the costs to repair damage caused by subsidence.
Are you looking for more information on subsidence? Download our infographic on buying, selling and letting a property with a history of subsidence. If you have questions about anything we’ve mentioned in this article or want to discuss subsidence in your property, feel free to contact our team.