Subsidence claims in the UK and the independent assessor

Subsidence, heave and settlement

In insurance terms, subsidence is the downward movement of the ground beneath a building that is not caused by the weight of the building itself. Heave is the opposite, upward movement, often when soil swells after a tree is removed. Landslip is a sideways movement. Settlement, the normal bedding-down of a new or extended building, is usually excluded.

Clay soils across much of southern and eastern England, including London, shrink as they dry and swell when wet, which is why claims often rise after hot, dry summers. Leaking drains can also wash away or soften soil under foundations, particularly on sandy or granular ground.

Early signs and when to notify

Typical signs include diagonal cracks wider than a few millimetres near doors and windows, cracks visible both inside and outside, doors and windows that start sticking, and gaps where an extension meets the main house. Notify your insurer as soon as you suspect subsidence, since a late report can complicate the claim and allow damage to worsen.

How a UK insurer handles the claim

Insurers often pass subsidence claims to specialist adjusters or claims management firms. They inspect the cracks, decide whether the movement is likely to be subsidence and arrange site investigations. Monitoring of crack widths or levels over several months is common, partly to confirm whether movement is ongoing and seasonal.

If vegetation is the suspected cause, the insurer may seek removal or pruning of trees, including those belonging to neighbours or the local council. Where trees are protected by a tree preservation order or a conservation area, consent is required. Repairs usually begin only after the cause has been dealt with and the building has stabilised.

• Initial inspection and crack mapping
• Trial pits, boreholes, soil and root analysis
• Drainage CCTV survey and repair of defective drains
• Monitoring over seasons
• Tree management or other mitigation
• Repair: crack stitching, partial or full underpinning, redecoration

What an independent assessor brings

The insurer's adjuster and engineers act for the insurer. An independent assessor or chartered surveyor appointed by you can review the investigation, ask for additional tests, query the length of monitoring, and challenge a repair proposal that seems too limited. They can also help you deal with neighbours and councils over trees, and make sure internal decoration and other consequential damage are included.

It is especially worth getting independent advice when the insurer suggests the damage is historic, caused by poor construction, or simply settlement, as these conclusions can defeat the claim.

Timing also matters. Monitoring that runs only through a wet winter may suggest the building is stable when movement resumes the following summer. An independent adviser can ask for readings across at least one full seasonal cycle where the soil type makes that relevant, and can check that repairs are not started before the cause has been properly addressed, which is a common reason for recurring cracks.

Evidence and records to keep

Ask for copies of every investigation report. You are entitled to understand the reasoning behind the insurer's decision.

• Dated photos of each crack, with a ruler or crack gauge for scale
• Notes of when doors or windows began to stick
• Your purchase survey and any previous subsidence history
• Building control sign-off for extensions
• Records of nearby tree work, drainage repairs or building works
• All reports and monitoring data supplied by the insurer

Typical areas of disagreement

Disputes often concern the cause of the movement, the need for underpinning versus treating the cause and repairing the superstructure, the duration of monitoring, and whether damage to garden walls or paths is covered. Another frequent issue is the property's future value and insurability: underpinned homes or those with a subsidence history can be harder to sell or insure, so a lasting, documented repair matters.

Changing insurer and the subsidence history

Insurers generally ask about past subsidence when you buy cover. Some households worry about switching insurer during an open claim. Industry practice for many years has been that, where buildings cover changes hands, the insurer on risk when damage is first discovered handles the claim, but check this with your broker when you move or switch. A certificate of structural adequacy at the end of repairs is a useful document for future buyers and lenders.

Complaints and the Financial Ombudsman Service

If you disagree with the insurer's handling or decision, complain in writing. The insurer generally has eight weeks to issue its final response, after which you can usually refer the matter to the Financial Ombudsman Service within six months. The Ombudsman regularly deals with subsidence complaints, including those about delays, inadequate repairs and decisions to rely on a single round of investigation.

Subsidence claims require patience and good records more than speed. If you are considering independent help, the subsidence fee guide on expertdassure.com explains the likely costs.