The short answer
Underpinning is often covered by buildings insurance when it is needed to repair subsidence damage, which is a standard insured peril on most UK home policies. If subsidence is confirmed, your insurer normally manages the claim, appoints engineers and loss adjusters, funds the investigation and pays for the agreed repair — which may or may not include underpinning, since modern practice often uses targeted repair rather than full underpinning. You typically pay a subsidence excess, commonly around £1,000, which is much higher than a standard claim excess. Insurance does not cover underpinning carried out for an extension, to add value, or for damage you cause yourself, and a property with a subsidence history can be harder and more costly to insure afterwards. Always claim through the insurer before commissioning private work.
Whether insurance pays depends entirely on the cause. Subsidence damage is usually insured; planned or elective underpinning is not. The notes below explain the typical UK position, not the terms of any specific policy — always read your own wording.
Typical UK position
- Subsidence repairusually covered by buildings insurance
- Subsidence excesscommonly around £1,000
- Extension / new foundationsnot covered
- Pre-existing / known defectmay be excluded
- Who manages the claimyour insurer's appointed experts
When insurance does and does not pay
- Covered: sudden subsidence damage during the policy period, where the cause is an insured peril such as ground movement from clay shrinkage, a leaking drain or removed vegetation.
- Carries an excess: the subsidence excess is typically around £1,000, set higher than normal because claims are expensive.
- Not covered: underpinning for an extension or to increase value, damage from poor original construction, gradual settlement of a new build, or movement you were already aware of when you took out the policy.
- May be limited: if a tree you own caused the movement, or if you delayed reporting, the insurer may dispute or reduce the claim.
How a subsidence claim usually runs
When you report cracking that may be subsidence, the insurer typically appoints a loss adjuster and a structural engineer, who carry out crack monitoring, a soil investigation and a drains survey, often over several months, to confirm the cause and whether it is still active. Only once the cause is identified and stabilised — for example by removing a tree or fixing a drain — is a repair scheme agreed. Many cases are resolved with localised repair and monitoring rather than full underpinning, because underpinning is reserved for cases where the foundation genuinely cannot be stabilised otherwise. The Association of British Insurers operates a domestic subsidence agreement so that, where two insurers are involved across a policy renewal, the claim is not left in limbo.
| Cause of underpinning | Insurance position |
|---|---|
| Subsidence (insured peril) | usually covered, minus excess |
| Extension / new build | not covered |
| Adding value / elective | not covered |
| Known defect at policy start | typically excluded |
General UK guidance. Sources: ABI subsidence guidance and your own policy wording.
The subsidence excess and the effect on premiums
Subsidence claims carry a separate, higher excess than ordinary buildings claims — commonly around £1,000 — because investigating and repairing ground movement is costly and drawn out. That excess is the part you fund yourself even on a fully accepted claim. After a subsidence claim, the property carries a recorded history, which can make it harder to insure at renewal or when you come to sell, and may attract higher premiums or the need for a specialist insurer. The picture is not as bleak as it sounds: the Association of British Insurers operates arrangements so that homes with a subsidence history remain insurable, and an existing insurer cannot simply walk away mid-claim. Keeping the engineer's certificate of structural adequacy issued once repairs are complete is important, because future insurers and buyers' surveyors will ask for evidence that the movement was diagnosed, the cause fixed and the repair signed off.
Why insurers often avoid full underpinning
A common misconception is that a subsidence claim automatically means the house will be underpinned. In practice, insurers and their engineers reserve underpinning for cases where the foundation genuinely cannot be stabilised any other way. The first response is usually to remove the cause — repair a leaking drain, manage or remove a tree (with care over heave on clay), or address the ground — and then monitor the cracking over a period, often spanning a full seasonal cycle, to confirm movement has stopped. Many homes are then repaired with crack stitching, repointing and redecoration rather than any foundation work at all. Underpinning is the exception, not the rule, partly because it is expensive and partly because it can introduce differential movement if only part of a building is supported. So even when a claim is accepted, the outcome may be targeted repair, not the wholesale underpinning homeowners often fear.
A final point often missed is the distinction between the building and its contents, and between repair and betterment. Buildings insurance covers reinstating the structure to its previous condition; it does not fund improvements, so an insurer will not pay to upgrade foundations beyond what is needed to repair the damage, nor to extend or add value while the ground is open. Damage to drives, paths and landscaping is sometimes treated differently from the house itself, and policies vary on how much external reinstatement they include, so it is worth reading those sections closely. Where tenants or leaseholders are involved, responsibility for arranging buildings cover and pursuing a subsidence claim can sit with a freeholder or managing agent rather than the occupier, which affects who reports and manages the work. Understanding exactly what your policy reinstates, and who holds the cover, avoids unwelcome surprises once the claim is underway.
Where people most often come unstuck is the gap between what a policy covers and what they assume it covers. A standard buildings policy covers sudden subsidence damage to the existing, insured structure, subject to the subsidence excess — but it does not fund the foundations of a new extension, betterment beyond putting the property back as it was, or movement that an insurer judges to be long-standing settlement rather than active subsidence. It is also worth knowing that the insurer, not you, appoints and manages the engineering team on an accepted claim, which is why the route is to report the damage and let the claim process run rather than commissioning private underpinning and seeking reimbursement afterwards. For leasehold flats the position is different again: the freeholder usually holds the buildings policy for the whole structure, so a subsidence claim on a flat typically runs through the freeholder or managing agent. The single most useful habit is to read the subsidence section of your own policy wording before anything goes wrong, so you know your excess, your insurer's claims line, and the boundary between what is covered and what is a planned cost you fund yourself.
| Insurer's likely response | When |
|---|---|
| Fix cause + monitor + cosmetic repair | most cases |
| Partial underpinning | localised foundation failure |
| Full underpinning | rare — widespread foundation failure |
General UK guidance. Source: ABI subsidence guidance and structural engineering practice.
Frequently asked questions
How much is the excess on a subsidence claim?
The subsidence excess is commonly around £1,000 on UK buildings policies, set higher than a standard claim excess because subsidence claims are expensive to investigate and repair. Check your policy schedule for the exact figure.
Will a subsidence claim make my house harder to insure?
It can. A property with a subsidence history may be harder to insure or attract higher premiums, though insurers offering specialist non-standard cover and the ABI's arrangements help keep affected homes insurable. Keep the engineer's certificate of completed repair for future insurers.
Does insurance cover underpinning for an extension?
No. Insurance covers damage from insured perils such as subsidence, not the cost of new or deeper foundations for an extension, which is a planned construction cost you pay for directly.
Sources & further reading
- ABI — subsidence and your home
- RICS — subsidence guidance for homeowners
- Checkatrade — underpinning cost guide
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation.