Subsidence and Buildings Insurance Explained

Subsidence is the downward movement of the ground beneath a building, which pulls the foundations down and can crack walls and distort the structure. Buildings insurance normally covers subsidence damage, but a higher excess, often around 1,000 pounds, usually applies to a subsidence claim. Claims can be long and involved, from monitoring the movement to underpinning the foundations, and a history of subsidence affects future cover.

Subsidence is one of the risks homeowners worry about most, because it strikes at the structure itself. The good news is that standard buildings cover includes it; the complication is the high excess and the length of a claim.

What is subsidence?

Subsidence happens when the ground under a property sinks, taking the foundations with it. The common cause is soil that shrinks as it dries out, often clay soil in dry spells, sometimes made worse by trees and shrubs drawing moisture from the ground near the house. The tell-tale sign is new, wide, diagonal cracking in walls, though not all cracks mean subsidence.

Does buildings insurance cover subsidence?

Yes, standard buildings insurance normally covers damage to the home from subsidence, along with heave and landslip. Cover usually applies to the main building and outbuildings, but damage to driveways, patios, paths and garden walls is often excluded unless the house itself is damaged at the same time.

Why is the excess higher for subsidence?

Subsidence claims are expensive and complex, so policies apply a higher excess to them, commonly around 1,000 pounds, compared with the smaller excess on other claims. If the property has claimed for subsidence before, the excess can be higher still, and cover can become harder to arrange.

What does a subsidence claim involve?

Because the cause has to be established, a claim can run for a long time. It may involve a period of monitoring to see how the building is moving, removing or managing nearby trees, repairing cracks, and in more serious cases underpinning to strengthen the foundations. If the home cannot be lived in during the work, the policy usually covers alternative accommodation. Buying or insuring a property with a subsidence history is a specialist matter, covered in our guide to home insurance with a subsidence history.

Getting the cover right

Subsidence cover is standard, but the excess, the exclusions and a property’s history all matter, and a home with any subsidence record needs careful placing. A broker can help arrange cover that many insurers shy away from. To review your home cover, call 01795 841 310 or speak to the team.

Subsidence, heave, landslip and settlement

Insurers treat four kinds of ground movement differently. Most buildings policies cover the first three and exclude the fourth.

Term	What happens	Usually covered?
Subsidence	The ground beneath the foundations moves downwards, often as clay soil dries and shrinks	Yes, with a higher excess
Heave	The ground swells and pushes upwards, for example when clay soil takes up water after a large tree is removed	Yes, usually under the same section
Landslip	Ground moves down a slope	Yes, usually under the same section
Settlement	A new building or extension beds down under its own weight	Usually excluded

Leaking drains can also wash away fine soil from under foundations. Many insurers treat the resulting movement as subsidence and the drain repair as part of the claim.

Who is most exposed: some UK examples

• A Victorian terrace on clay with shallow foundations and mature street trees outside.
• A 1930s semi with a later extension built on different foundations, where the two parts move at different rates.
• A landlord buying a house that was underpinned years ago, who has to find cover that does not exclude subsidence.
• Freeholders and residents’ management companies insuring a block of flats where one corner has cracked.
• A business owner whose shop or office sits on a slope near a river bank.

What to do when cracks appear

Record the crack, tell your insurer early and leave it alone. Repairs done too soon hide the evidence an engineer needs.

1. Photograph and date it. Include a ruler or coin for scale.
2. Mark the ends with a pencil line and the date, so you can see if it grows.
3. Look for other signs: doors or windows that start to stick, cracks that are wider at the top than the bottom, or gaps opening between an extension and the house.
4. Do not fill or decorate over it until the insurer or engineer agrees.
5. Do not cut down trees yourself. Removing a large tree can cause heave. In England, works to a tree protected by a Tree Preservation Order need the local planning authority’s written consent, and certain works to trees in a conservation area need six weeks’ notice to the council.
6. Tell your insurer or broker. Most policies require prompt notification, and early monitoring can shorten the claim.

How a subsidence claim works

1. Notification. The insurer usually appoints a loss adjuster or a specialist subsidence firm.
2. Site investigation. This often includes trial pits next to the foundations, soil and root samples, and a camera survey of the drains.
3. Monitoring. Cracks or levels are measured over several months, often through dry and wet seasons, to confirm the cause and whether movement is continuing.
4. Removing the cause. Typical steps are repairing drains or managing a tree. Where a tree is protected, the application for consent must include evidence that the tree is a material cause of the damage.
5. Stabilisation if needed. Underpinning is used where removing the cause is not enough. The Planning Portal says underpinning will normally need building regulations approval. If excavation is close to a neighbour’s foundations, the Party Wall etc. Act 1996 can require at least one month’s notice to the adjoining owner.
6. Repairs. Once the building is stable, cracks are repaired and the property redecorated.
7. Sign off. Many insurers or engineers provide written confirmation that the building is stable. Keep it: future insurers and buyers will ask for it.

Exclusions to check

The page above covers drives, paths and garden walls. Other common exclusions are:

• settlement, shrinkage or bedding down of new structures;
• coastal or river bank erosion;
• faulty design, workmanship or materials;
• movement caused by demolition, structural alteration or repair work;
• damage that started before you took out the policy;
• damage to solid floor slabs alone, unless the main walls are damaged at the same time, on many policies.

What affects your premium and terms

• Soil type and the subsidence record of the postcode.
• Trees near the building, their species and how close they are.
• Age, construction and foundations of the building.
• Any previous claim, underpinning or monitoring, and whether a stability certificate is available.
• The excess you choose and whether the insurer adds a subsidence exclusion.

Telling insurers about past subsidence

You must answer the insurer’s questions accurately. For a home bought as a consumer, the Consumer Insurance (Disclosure and Representations) Act 2012 requires you to take reasonable care not to make a misrepresentation.

For a business, including a landlord insuring a let property, the Insurance Act 2015 applies a wider duty of fair presentation. You must disclose every material circumstance you know or ought to know, not just answer the questions asked. Getting this wrong can lead to a claim being reduced or refused.

A worked example (hypothetical)

After a dry summer, the owner of a 1950s semi on clay notices a diagonal crack above the kitchen window and a back door that will not close. She photographs it, marks the ends and calls her broker the same week.

The insurer’s engineer finds roots from a neighbour’s large tree in the soil samples and a cracked drain nearby. The drain is repaired under the claim. The tree is protected, so the insurer’s arborist applies for consent to reduce it, supported by the investigation results.

Monitoring through the following winter shows the house has stabilised, so underpinning is not needed. The cracks are repaired, the policy pays the claim less the subsidence excess, and the owner receives a letter confirming the building is stable to keep with her deeds.

Frequently asked questions

Do I have to tell a new insurer about past subsidence?

Yes, if the insurer asks, and most do. Answer accurately and keep the engineer’s reports and any stability certificate to hand.

Can I cut down a tree that is causing subsidence?

Not without advice. Removing a large tree can cause heave, and protected trees need consent from the local planning authority. Let the insurer’s specialists decide.

Who pays if my neighbour’s tree caused the damage?

Your own buildings insurer usually handles the claim. It may then try to recover its costs from the tree’s owner.

Does subsidence always mean underpinning?

No. Many claims are resolved by removing the cause, such as a leaking drain or tree roots, and then repairing the cracks.

Do I need building regulations approval for underpinning?

Normally yes. The Planning Portal says approval will normally be required to underpin an existing foundation.

Is subsidence covered if the damage started before I bought the house?

Usually not. Policies cover damage that happens during the period of insurance, which is why a survey before purchase is worth reading closely.

Related guides

• Property owners liability insurance
• HMO insurance and licensing
• Landlord insurance explained
• Block of flats insurance