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Underpinning: what impact might it have on your home insurance?

If your house has subsidence and needs underpinning, you may be wondering what effect it will have on your home insurance. Let’s take a look at the main points.

If your house has subsidence and needs underpinning, you may be wondering what effect it will have on your home insurance. Let’s take a look at the main points.

Written by
Helen Phipps
Insurance comparison expert
Reviewed by
Rachel Lacey
Insurance and money expert
Last Updated
21 OCTOBER 2022
6 min read
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What is underpinning a house?

Underpinning is a process that strengthens the foundations of a building to make it more secure. It’s often used when a house has subsidence – that’s when the ground beneath the building moves or sinks downwards.

How much does it cost to have your house underpinned?

The cost of underpinning a house depends on a whole range of factors, such as the size and the extent of work that needs doing. Generally speaking, you could be looking at somewhere in the region of £15,000. If you live in a large house or the situation is complicated, that figure could be far higher.

How does underpinning work?

The underpinning process is time-consuming and complicated – but essentially, the existing foundations are lengthened, often many metres down, and skewered into the ground. Different underpinning methods can be used, depending on the extent of the problem:

  • Soil strengthening – the least expensive method of underpinning, where a type of resin foam is injected into the earth to replace the eroded soil around the property’s foundations.
  • Mass concrete – pits are dug below the existing foundations and filled with concrete to create supporting layer underneath.
  • Beam and base – uses a concrete beam below the existing foundation to distribute the weight of the building onto concrete bases.
  • Screw piles and brackets – this more modern technique uses screw piles inserted deep into the ground, which then act as anchor points for supporting brackets to level off the foundation.

Can you insure an underpinned house?

Finding buildings insurance for underpinned houses shouldn’t be too hard as numerous providers offer this type of cover. But it could be more expensive.

Should I buy a property that’s been underpinned?

If you’ve fallen in love with a house that’s been underpinned, one of the first tasks to consider doing is getting a full structural survey. This will tell you whether there are any ongoing issues affecting the property.

Bear in mind that there’s a risk the property could be harder to sell in the future. It’s impossible to generalise, though. In some areas where subsidence is common, people aren’t so concerned about an underpinned property. And remember that just because a property is underpinned, it doesn’t mean it’s suffered from subsidence – although it does pay to be wary.

If you do buy an underpinned property, don’t forget to have your buildings insurance in place from the day you exchange, rather than waiting until you move in. As soon as the exchange takes place, the property becomes your responsibility.

How do I know if my house has subsidence?

If you’re worried that your house might have subsidence, here’s a few tell-tale signs to look for:

  • Cracks in the building. Not all types of cracks are a sign of subsidence. Most of them are caused by settling – especially in new-builds. But keep an eye on any cracks that appear quite suddenly, around doors and windows. Subsidence cracks are often diagonal and appear wider at the top and are visible from the outside of the property, not on the internal plaster.
  • Windows and doors won’t open. If you find you’re struggling to open and close doors, it could be that subsidence has caused the building to shift. Doors can swell and shrink with changes in temperature and moisture levels, or it may be that a couple of screws in the hinges need tightening. But you should contact a building expert if you have any concerns.

Did you know?

Research by Comparethemarket reveals that two fifths of homeowners don’t check for subsidence and flooding risks before buying their home.

Is my home at risk from subsidence?

Some houses are more at risk from subsidence than others. Risk factors might include:

  • The type of soil you have. Clay soil is a particular risk as it could shrink and crack in dry weather, making the ground unstable. This effect can be exaggerated if there are periods of heavy rain, making the clay wet and swell, followed by hot and dry periods – the movement in swell and shrink of the clay is more significant and can cause issues. Clay is more common in the south east.
  • Water damage. Leaking drains can soften the underlying ground.
  • Trees close to the house. They drain the moisture from the soil, causing it to dry out and sink.
  • Living in a period property. Older houses tend to be at higher risk of subsidence as their foundations aren’t always as deep as new-builds.

What should I do if I think my house has subsidence?

Call your insurance provider. The sooner subsidence is dealt with, the better.

Can you get a mortgage on a house that has been underpinned?

Typically, a lender can offer a mortgage for an underpinned house if the structural survey report proves the work has been finished to a high standard. Also, there should be no ongoing issues with the property’s structure. A house with subsidence that’s not been repaired may be more difficult to get a mortgage for.

How to tell if a house has been underpinned?

It can be difficult to tell if a house has been underpinned just by looking at it. This is because the underpinning work will be concealed underground and might not show up during a standard survey inspection.

If your house shows obvious signs of subsidence – large, deep cracks in walls, and finer cracks around windows and doors – but you’re not sure if it’s been underpinned, you’ll need to get a structural engineer to carry out a Building Survey (previously called a Structural Survey), which is more in-depth than a standard RICS Homebuyers Report. This should be able to identify any structural issues, and whether the building has been, or needs to be, underpinned.

Do you have to declare subsidence when selling a house?

When selling a house, you should let the estate agent and buyer know that your home has been affected by subsidence. If you’ve made a claim for subsidence in the past, you may want to pass on the insurance provider’s name, so the new buyer can continue the cover in case another subsidence claim needs to be made in the future.

How do I get cover for subsidence and underpinning?

The ideal way to find the right insurance policy for you is to compare quotes from a range of insurance providers. All you need to do is give us a few details about yourself and your property and we’ll do the rest.

Frequently asked questions

Can I claim the cost of underpinning on my home insurance?

Subsidence damage is usually covered by buildings insurance, so you should be able to claim back the cost if your house needs underpinning.

Underpinning might not be covered by your home insurance if:

  • Subsidence has been caused by major structural changes you’ve made to your home, such as building an extension.
  • Subsidence occurs on a new-build property that’s still covered by a new-build warranty – this is because the home builder could be responsible for the underpinning. If this isn’t covered under the warranty, you should contact your insurance provider.

You’ll probably have to pay an excess of £1,000 rather than your standard excess if you make a claim for subsidence.

What should I do if my house was underpinned and I wasn’t told?

The seller or estate agent should have declared any past work on the Property Information Form when you bought the house. If not, you could sue them under the Misrepresentation Act (1967). They would need to prove that they didn’t know about the underpinning.

If you have additional legal cover as part of your home insurance, you should be able to claim any legal expenses incurred if you sue.

Is an underpinned house more expensive to insure?

If your house has been underpinned in recent years, your buildings insurance will probably be more expensive. In theory, underpinning should mean it’s more stable now, but there’s still a potential risk of further instability.

However, if the underpinning was done a long time ago and there’s no further evidence of subsidence over the years, it might not have such an impact on the cost of your premiums.

Will I have to pay more excess for an underpinned house?

You might do. Some insurance providers will set a much higher excess for subsidence claims on an underpinned house. For example, if a standard excess is £1,000, this may be upped to £2,500 for an underpinned house policy.

Do I have to tell my insurance provider if my house is underpinned?

Yes, you should always be 100% honest and let your insurance provider know if your house is underpinned. Even if the work was done decades ago and no further movement has occurred, there’s still a risk of damage from subsidence in the future. Failing to inform your insurance provider could invalidate your policy.

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Helen Phipps - insurance expert

Having worked in both sides of the industry, Helen’s a real insurance expert. She’s worked directly with several insurance providers and now Compare the Market. She’s always searching for the cheapest prices for customers and is passionate about saving people money. Being married with two kids, Helen knows all about the cost of living and the benefits of having the right products and insurance for the whole family.

Learn more about Helen

Rachel Lacey - Insurance and money expert

Rachel’s a self-confessed money nerd who’s been writing about personal finance for more than 20 years. She spent 17 years writing for Moneywise, including a few years as Editor, and likes making complicated subjects like insurance, pensions, investing and tax, easy for people to understand.

Learn more about Rachel

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