Subsidence is one of the most feared words in home ownership, and one of the least understood insurance processes. Having handled subsidence claims from the insurer’s side as a regional technical surveyor, I can tell you the process is more methodical — and usually less catastrophic — than most policyholders expect. Here is how a claim actually unfolds.
Step 1: notification and triage
You notice cracking (or a drain survey, surveyor or builder flags it) and notify your buildings insurer. Subsidence is a standard insured peril in UK buildings policies, usually with a higher excess — commonly £1,000.
The insurer’s first job is triage: does the damage pattern actually suggest subsidence? A significant proportion of notifications are closed at this stage because the cracking is thermal, shrinkage or historic movement. That is not the insurer dodging the claim — most cracking genuinely is not subsidence.
What to do: photograph everything with a scale reference and dates before anyone visits. Do not redecorate over the cracks; the evidence matters.
Step 2: initial technical inspection
If triage suggests possible subsidence, a surveyor or engineer inspects. They will map the cracking, assess the pattern (diagonal stepping through mortar joints, tapering, inside-outside correspondence), and survey the site: trees and their species, drainage runs, slopes, and the age and construction of the building.
The output is usually one of three views: not subsidence (claim declined, with reasons), subsidence with an obvious cause (move to investigation to confirm), or unclear (investigation needed).
Step 3: investigation
This is where the claim slows down, and where policyholders often lose patience — but it is the most important phase. Typical investigations include:
- CCTV drainage survey — leaking drains are among the most common and most fixable causes
- Boreholes or trial pits — establishing soil type, foundation depth and moisture content
- Root analysis — identifying which vegetation is implicated, and whose
- Level and crack monitoring — precise measurements repeated over months to establish whether movement is ongoing and whether it is seasonal
Monitoring typically runs six to twelve months, sometimes through a full seasonal cycle. This feels glacial when your wall is cracked, but intervening before the cause is proven wastes money and frequently fails.
Step 4: mitigation — addressing the cause
Once causation is established, the cause is removed or managed:
- Vegetation — removal or reduction of the implicated trees. Where a neighbour’s or council tree is involved, this can add months of liaison (and occasionally a recovery claim against the tree owner).
- Drainage — repair or relining of defective drains.
- Heave risk check — before removing a mature tree on shrinkable clay, the risk of the ground swelling as it rehydrates has to be considered. This is why “just cut the tree down” is not always the first move.
In the majority of claims, mitigation plus a period of confirmed stability is enough. Underpinning is the exception, not the rule — it is required only where the ground cannot be stabilised by removing the cause.
Step 5: repair
Once monitoring confirms the building is stable, repairs are scoped and carried out — typically crack repair, re-pointing, replastering and redecoration. Structural repairs such as partial rebuilding or underpinning are specified by an engineer where genuinely needed.
Check the scope carefully before signing it off. Under-scoped subsidence repairs — hairline “making good” over movement damage that needed stitching or re-building — are a recurring source of disputes and repeat claims.
Step 6: the paperwork that matters
At the end of a properly handled claim you should receive documentation, often including a Certificate of Structural Adequacy (CSA) where structural repairs were completed under professional supervision. Keep everything: the investigation reports, monitoring data, scope of works and completion certificates.
This file is what makes the property saleable and insurable later. A documented, investigated, repaired subsidence history is a manageable thing; an undocumented one is a valuation problem.
Where claims go wrong
From the inside, the same failure points recur:
- Causation disputes — “wear and tear”, “settlement” or “pre-existing” declinatures that do not always survive independent scrutiny.
- Investigation drift — monitoring that runs on without decisions being made.
- Under-scoped repairs — cosmetic fixes for structural damage.
- Communication vacuum — months of silence between milestones, leaving policyholders in the dark in a stressful situation.
An independent technical opinion is most valuable at three moments: when a claim is declined on causation grounds, when a repair scope looks thin, and when repairs are complete but you are not confident they are right. That is precisely the gap independent claims consultancy exists to fill — including, where necessary, supporting a Financial Ombudsman Service referral with a proper technical case.
The realistic timeline
A straightforward subsidence claim — clear cause, cooperative parties — commonly runs 12 to 18 months from notification to completed repairs. Complex claims run longer. Knowing that at the outset makes the process far less alarming: the pace is a feature of doing it properly, not a sign your insurer has forgotten you.