How Much Does Subsidence Repair Cost in London?
Subsidence repair is really four possible costs: diagnosis, removing the cause, repairing the damage, and, only sometimes, underpinning. Here is what each stage involves and costs in 2026.
In short: the cost of fixing subsidence depends on whether the cause can simply be removed. Diagnosis starts with a subsidence assessment and full written report at £495 to £895 + VAT depending on the size of the property and the type of movement. Where the fix is removing the cause, repairing a leaking drain or managing a tree, plus repairing the cracks, total costs are commonly in the low thousands. Where underpinning is genuinely needed, our indicative design-and-build rate is around £1,500 per metre run, and whole projects commonly run from around £10,000 to £50,000 or more. Most subsidence cases do not end in underpinning: current engineering guidance is to deal with the cause first and underpin only where movement continues. If you are insured, most policies cover subsidence damage with a typical £1,000 excess, and on an accepted claim the insurer normally funds the investigation and monitoring stage, which usually runs six to twelve months. Figures correct as of September 2026, every job priced by written quotation after diagnosis.
The four cost stages of subsidence repair
Subsidence worries people because the worst-case numbers get quoted first. In practice the spend arrives in stages, and each stage exists to stop you paying for the one after it unnecessarily.
| Stage | What it involves | Indicative cost |
|---|---|---|
| 1. Diagnosis | Engineer's inspection and full written report: is it subsidence, what is the likely cause, what happens next | £495 to £895 + VAT (EMA fee, by size of property and type of movement) |
| 2. Investigation, if needed | Trial pits to expose foundations, CCTV drain survey, crack and level monitoring, typically 6 to 12 months | Monitoring set-up plus three seasonal visits £1,200 to £2,000 + VAT, extra visits £350 + VAT each (EMA fees); drain CCTV surveys commonly low hundreds; trial pits quoted; usually insurer-funded on an accepted claim |
| 3. Removing the cause and repairing damage | Drain repair or tree crown reduction, then crack stitching, repointing, replastering and redecoration | Commonly low thousands in total, site-specific |
| 4. Underpinning, minority of cases | Mass concrete underpinning in sequenced 1 m bays to about 2.5 m deep, design and build; mini-piles beyond that | ~£1,500 per metre run (EMA rate); projects commonly £10,000 to £50,000+ |
Indicative figures for budgeting only, correct as of September 2026. EMA Structures fees and rates are confirmed by written quotation; third-party costs such as drain repairs and tree works vary by contractor and site.
Stage 1: diagnosis, the assessment that protects the rest
Cracking that looks like subsidence often is not: thermal movement, plaster shrinkage, failed lintels and normal settlement produce similar symptoms. The first step is an engineer confirming whether the pattern actually indicates foundation movement, our guides to the signs of subsidence and crack types cover what we look for. A subsidence assessment with a full written report costs £495 to £895 + VAT, depending on the size of the property and the type of movement, and sets out the likely cause, its severity and the next step, which is sometimes simply "monitor and do nothing yet".
Stage 2: investigation and monitoring
Where the cause is not clear from inspection, the honest answer is evidence, not guesswork. The tools are simple, and the numbers they produce are what decide between a repair costing a few thousand pounds and one costing tens of thousands:
- Crack monitoring. Stainless steel studs are fixed either side of each significant crack and read with a digital calliper to a tenth of a millimetre. Glass tell-tales glued across a crack are not accurate enough for this and we do not rely on them.
- Level monitoring. A precise level survey along a brick course near the damp-proof course, repeated every six to eight weeks, shows which part of the building is moving and by how much. Trees produce a seasonal pattern, down in summer and back up in winter; a leaking drain or soft fill produces steady, one-way movement.
- Drain survey. A CCTV survey, commonly low hundreds of pounds, plus a water test to measure how much a suspect run is actually leaking.
- Trial pits and ground tests. Our specialist site team excavates beside the footing so the engineer can record its depth and what it bears on, extends the hole with a hand auger to around 3 m, and takes samples for moisture and plasticity testing where clay shrinkage is suspected.
Monitoring typically runs for six to twelve months, and on an insurance claim it is often longer, because a full summer and winter are needed to tell seasonal movement from progressive movement. It feels slow, but it is dramatically cheaper than underpinning a wall that stopped moving years ago. Our fee for installing the studs and markers and taking three seasonal readings is £1,200 to £2,000 + VAT depending on the property, with further visits at £350 + VAT each, and on an accepted claim the insurer normally funds this stage. Our guide to crack and level monitoring explains what the readings show.
Stage 3: remove the cause, repair the damage
The most common outcomes are the cheapest ones. London subsidence is dominated by two causes: shrinkable clay drying out around tree roots, and leaking drains washing out or softening the ground. Roughly 70% of UK subsidence is clay-related, and about half of all cases involve a tree or large shrub, more in a drought year. Current guidance from the Institution of Structural Engineers sets the order of work plainly: confirm the building is basically stable, deal with the ground (drains, trees, moisture), and only then consider the foundations. Underpinning is the last option, not the first.
Where the remedy is a tree (our guide to trees and subsidence covers the decision), the usual answer is crown reduction by an arboriculturist rather than felling, repeated every two to three years for as long as the tree stands, because the crown grows back. Crown thinning does not reduce a tree's water uptake and is no longer recommended. Felling a mature tree carries its own risk, heave, as the dried clay slowly swells again, so it needs an engineer's view first, and a tree with a preservation order or in a conservation area needs council consent before anyone touches it. Where the remedy is a drain, expect the ground to go on settling for up to a year after the repair while the softened soil dries and consolidates, which is why the crack repairs are timed after monitoring rather than straight after the drain works. Our guide to leaking drains and subsidence covers how the leak is found and who pays for the pipe.
Once movement has stopped, the remaining work is repairing the damage: crack stitching and repointing, localised rebuilding where brickwork has displaced, replastering and redecorating. Repairs are specified and inspected through an engineering-led repair process so they address cause, not just appearance.
Stage 4: underpinning, the minority outcome
Underpinning is only the answer where the foundations remain unable to support the building even after the cause is dealt with, live, progressive movement that cause-removal cannot arrest. Our guide to when underpinning is needed explains how that decision is made. As a design-and-build firm we publish our indicative rate: around £1,500 per metre run for traditional mass concrete underpinning with pins to 1 m deep, covered in more detail in our basement and underpinning cost guide. How much of the building needs underpinning drives the total, one corner of a bay window is a very different project from a full flank wall, which is why whole projects range from around £10,000 to £50,000 or more.
Three things move the price beyond the rate per metre. Depth: mass concrete is dug and cast in bays of about a metre with no more than a third of the wall open at once, and it is economic to roughly 2.5 m; below that the safer and usually cheaper answer is mini-piles with a beam or raft, which also sends far less spoil off site. Ground: London Clay carries sulphates, so the concrete is specified sulphate-resisting, and where a tree has recently been removed the design needs anti-heave measures such as sleeved piles and a compressible void beneath the beams. Extent: most underpinning is partial, and that is normal practice rather than a compromise; foundations that have not moved are left alone once the cause is fixed, with transition pins so there is no hard step in foundation depth. Add to that a Building Regulations application, which underpinning always needs, and Party Wall notices where a shared wall is pinned or the excavation is within 3 m of a neighbour's foundations and goes deeper than them.
The insurance route
Most UK buildings insurance policies cover subsidence damage, usually with a higher excess than other claims, £1,000 is typical. Cover is for damage to the insured buildings caused by movement of the ground they stand on; it is not for preventative work where nothing has yet cracked, and it does not compensate for any loss in value. The insurer appoints a loss adjuster and their own consultants, and the process is slow because it includes the same monitoring stages described above, often twelve months or more. Our guide to subsidence insurance claims walks through the whole process, stage by stage.
What is commonly excluded, subject to your own wording: settlement of a building under its own weight, often defined as anything within ten years of construction; damage caused by your own alterations or repairs, or by defective design or workmanship; and, the two that surprise people most, ground-bearing floor slabs, and paths, drives, patios, garden walls and fences, unless the main house is damaged by the same cause at the same time. You also carry duties: report damage promptly, and maintain the property, which includes managing your own trees and repairing your own drains. A claim can be reduced where that has been neglected.
| Item | Who usually pays |
|---|---|
| Initial appraisal, investigation and monitoring | The insurer, on an accepted claim |
| Tree works needed to stabilise the building | Usually the insurer, as part of stabilisation; the ongoing pruning afterwards is yours |
| Drain repairs | Often the insurer where they are needed to stabilise the building, or under the accidental damage section with its own excess; replacing worn-out drains is yours |
| Structural repairs and underpinning | The insurer, less your excess |
| Your own independent engineer | Usually you, unless agreed with the insurer first |
| Works to a neighbour's tree or drain | Rarely the insurer; a separate matter with the neighbour |
General practice under typical UK household policies; wordings differ, check your own.
Two things are worth knowing. You are entitled to commission your own independent engineer's report, which is useful for checking that the proposed remedy matches the actual cause. And a claim does not make the house uninsurable: your existing insurer will normally continue cover after repairs, sometimes with a higher excess, and if you switch, the ABI agreement between insurers on subsidence claims notified after a change of insurer smooths the first year. What keeps a repaired house insurable and mortgageable is the paper trail: the investigation report, the repair specification, the Building Regulations completion certificate, the contractor's guarantee (ten years is now standard, ask whether it is insurance-backed) and the engineer's Certificate of Structural Adequacy at the end. Keep all of it, the next buyer's solicitor will ask. For minor, clearly diagnosed cases some owners choose to repair without claiming; that is a judgement about premiums, and insurers still ask about known subsidence at renewal, so keep the engineer's report either way.
Getting a real number
If you are seeing cracks and suspect movement, start with the diagnosis, not a repair quote. Send us photos of the cracks and we will give you an initial view, then a fixed-fee subsidence assessment and report, £495 to £895 + VAT depending on the property, if it warrants one. Because EMA Structures carries out the subsidence assessment and designs the repairs and underpinning, with our specialist construction arm able to deliver them under engineering oversight, the number you get reflects how the job will actually be done.
All figures exclude VAT unless stated, are indicative and correct as of September 2026, and are not quotations. EMA Structures fees are confirmed by written quotation; third-party and insurance-route costs vary by provider and policy.
Subsidence repair cost questions
How much does it cost to repair subsidence?
It depends almost entirely on the cause and whether foundation works are needed. Where the cause can be removed, a leaking drain repaired or a tree managed, and the cracks then repaired, costs are commonly in the low thousands of pounds. Where underpinning is required, EMA Structures' indicative design-and-build rate is around £1,500 per metre run of wall with 1 m deep pins, and whole projects commonly run from around £10,000 to £50,000 or more depending on how much of the building is affected. Diagnosis comes first: a subsidence assessment with a full report costs £495 to £895 plus VAT depending on the size of the property and the type of movement, correct as of September 2026.
How much does it cost to fix subsidence in the UK?
Broadly the same as in London, because the cost is driven by the cause and by whether the foundations need work, not by where you are. Across the UK, where the cause can be removed and the cracks then repaired, subsidence is commonly fixed for a few thousand pounds. Where underpinning is genuinely needed it is far more, often from around £10,000 to £50,000 or more depending on how much of the building is affected, with the underpinning itself frequently in the region of £1,500 per metre run of wall. London and the South East see more subsidence than most of the country because of the shrinkable clay soils. Diagnosis always comes first, and every job is priced by written quotation after inspection.
Can subsidence be fixed without underpinning?
Yes, and in the majority of cases it is. If movement stops once the cause is removed, for example a repaired drain or a managed tree, the remaining work is repairing the cracks and redecorating. Underpinning is only needed where the foundations remain unable to support the building after the cause is addressed, which is the minority of cases. An engineer's diagnosis, sometimes supported by a period of monitoring, is what makes that call safely.
Does buildings insurance cover subsidence repair?
Most UK buildings insurance policies cover damage caused by subsidence, typically with a higher excess than other claims, £1,000 is common. The insurer usually appoints a loss adjuster and consultants, and on an accepted claim normally funds the investigation and monitoring as well as the repairs. Common exclusions are settlement within about ten years of construction, damage from your own alterations, ground-bearing floor slabs, and paths, drives and garden walls unless the house itself is damaged by the same cause at the same time. You are entitled to commission your own independent engineer's report, which can be valuable for checking that the proposed remedy addresses the actual cause. Check your own policy wording, as cover and excesses vary.
What does subsidence insurance not cover?
Typically: settlement of the building under its own weight, often defined as anything within ten years of construction; made-up ground bedding down; damage caused by your own building work or by poor design or workmanship; ground-bearing floor slabs unless the external walls are damaged at the same time; and paths, drives, patios, garden walls and fences unless the main house is damaged by the same cause. Preventative underpinning where nothing has cracked is not covered either, nor is any loss in value. Wordings vary, so check your own policy.
How do you repair subsidence cracks?
Only after movement has stopped or the cause has been dealt with. Typical repairs are crack stitching with helical stainless steel bars bonded across the crack, repointing, localised rebuilding of displaced brickwork and internal replastering. Repairing cracks while the ground is still moving wastes money, because the cracks reopen.
How long does a subsidence claim or repair take?
Longer than most building work, because diagnosis usually includes six to twelve months of crack and level monitoring, often more on an insurance claim, to confirm whether movement is seasonal or progressive before a remedy is chosen. Straightforward cause-removal cases can conclude within a few months; cases involving monitoring, trial pits and underpinning commonly run twelve months to two years end to end.
Can I still insure and sell my house after subsidence?
Yes, in the great majority of cases. Your existing insurer normally continues cover once repairs are complete, sometimes with a higher excess, and a switch to a new insurer is smoothed by the ABI agreement between insurers on subsidence claims notified after a change of insurer. Lenders and buyers want to see that the cause was found and dealt with, so keep the engineer's report, the repair specification, the Building Regulations completion certificate, the contractor's guarantee and the Certificate of Structural Adequacy. Historic, stabilised movement does not stop a property being mortgaged.
What is a Certificate of Structural Adequacy?
A document issued by the engineer at the end of a subsidence repair. It records the damage, the cause found by investigation, the stabilisation measures and the remedial works, and confirms that the engineer designed or reviewed the scheme, that Building Regulations approval was obtained and that the works were inspected. It is a professional opinion rather than a guarantee, but it is what insurers, lenders and buyers' solicitors look for, and it should come with as-built drawings of any underpinning.
Worried about subsidence?
Send us photos of the cracks and we will tell you honestly whether it looks like movement, and what the sensible next step costs.