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Subsidence and underpinning cost

What it costs, how long it takes and what the insurer does, from RICS, the Financial Ombudsman Service, the British Geological Survey, the legislation and the price sources I could open on 20 September 2026. Where they copy each other, I say so.

How much does it cost to fix subsidence, and how long does it take?

Underpinning a typical house costs £10,000 to £75,000 according to RICS, and a quantity surveyor writing for Homebuilding & Renovating puts a typical three-bedroom semi at £10,000 to £30,000. Per metre of wall, traditional mass concrete underpinning comes out at £1,000 to £1,500 in the two sources that measure it that way. Most subsidence is never underpinned, though: RICS estimates that fewer than 5% of affected properties need it, because dealing with a tree or repairing a leaking drain usually stops the movement. With buildings insurance you normally pay the excess, commonly £1,000, and the insurer pays the rest. Time is the bigger cost. Cracks are monitored for as long as 12 months, RICS allows up to two years from first investigation to finished repair, and the underpinning itself takes 3 to 5 weeks in the one guide that puts a number on it.

Check the underpinning contractor for free

Before you sign for a five-figure job: is the company active, are the accounts filed, is there an insolvency history. Straight from the public register.

Is it subsidence at all

  • What subsidence is. The foundations move down because the ground supporting them changes. RICS separates it from settlement. RICS consumer guide, What is subsidence and how is it caused?The source says: "Subsidence is the downward movement of the foundations of a building due to changes in the supporting strata. It is different from settlement."
  • Settlement is something else, and usually not insured. Settlement is the soil being compressed by the weight of the building within 10 years of construction. Financial Ombudsman Service, Definitions of ground movement typesThe source says: "Downward movement as a result of soil being compressed by the weight of a building within 10 years of construction."
  • A crack is not proof. Every property cracks at some point, and cracking in itself is not evidence of subsidence. Financial Ombudsman Service, Problems that can be confused with ground movementThe source says: "Cracking in itself isn't evidence of subsidence."
  • The hallmark: parts of the house moving at different rates. What marks subsidence is differential movement. Financial Ombudsman Service, CrackingThe source says: "The hallmark of subsidence is differential movement, meaning different parts of the building moves at different rates."
  • When to worry. RICS: rarely any cause for real concern unless cracks appear suddenly and are more than 3mm wide. RICS consumer guide, How can I tell if my house is subsiding?The source says: "there is rarely any cause for real concern unless cracks appear suddenly and are more than 3mm wide."
  • Where it happens. Clay soils that change volume are most common in the London area and the south-east of England. British Geological Survey, Swelling and shrinking soilsThe source says: "Clay soils (e.g. the London Clay, which is very susceptible to volume change) are found in many areas of the UK, but are most common in the London area and in the south-east of England."

That distinction is worth money. The ombudsman lists settlement, the kind that happens within 10 years of construction, among the causes of cracking that are often uninsured. Which of the two you have is the first thing an insurer will want to establish.

Does it need underpinning

  • Underpinning is the exception. RICS: fewer than 5% of properties with subsidence are estimated to need underpinning, and the Institution of Structural Engineers recommends it only as a last resort. RICS consumer guide, UnderpinningThe source says: "It is estimated that fewer than 5% of properties suffering from subsidence need underpinning, and the Institution of Structural Engineers recommends it is only used as a last resort."
  • Trees are the usual cause. RICS quotes the Which? estimate that about 70% of cases come from tree roots drying out a shrinkable soil. RICS consumer guide, Tree rootsThe source says: "Consumer organisation Which? estimates that about 70% of all subsidence cases are due to tree roots sucking moisture out of a shrinkable soil."
  • Do not just fell the tree. Removing a mature tree that was there before the house can make things worse; the BGS says to take advice first. British Geological Survey, Six ways to prepare your homeThe source says: "Do not remove mature trees that pre-date the construction of the house before taking advice."
  • A leaking drain can be the whole problem. Where leaking pipework washes the soil away, repairing it is usually enough to stabilise the property without underpinning. RICS consumer guide, PipeworkThe source says: "In most cases, repairs to leaky pipework will usually be enough to stabilise the property without underpinning."
  • Owner wants underpinning, insurer offers less. The ombudsman lists it among the complaints it sees: the customer wants the entire property underpinned and the insurer says less extensive measures will do. Financial Ombudsman Service, Types of complaint we seeThe source says: "when the customer wants the entire property underpinned but the insurer says that less extensive remedial measures will do"

I put this above the prices on purpose. If fewer than 5% of cases end in underpinning, the cost table below is not the first thing you need. Find the cause first. The quote comes after.

What underpinning costs

Per metre of wall, traditional mass concrete, in the sources that measure it that way:

SourcePer metre of wallWhat is in it
Mainmark UK, How much does underpinning cost in 2025?£1,000 to £1,500A rough indication per linear metre of wall; VAT is not mentioned.
EMA Structures, How Much Do Basements and Underpinning Cost in London?around £1,500, or £1,800 with VATLabour and materials, traditional mass concrete, pins to 1 m deep, London. Excludes VAT.
MyJobQuote and Checkatrade£1,500, labelled per m2Labour and materials for the underpinning itself; VAT is not mentioned. The engineer, building control and any party wall award come on top.

About that last row. Checkatrade, MyJobQuote, Zapperty and the opening of the Mainmark page all publish the same numbers, down to the pound. That is one measurement printed four times, and I count it once. They call it a price per m2, but MyJobQuote's own worked examples say otherwise: £6,000 for 4 metres, £13,500 for 9 metres and £21,000 for 14 metres, which is £1,500 times the metres each time. So it is a price per metre of wall, and it agrees with the two sources that measure their own work.

The whole job, starting with the one source that has nothing to sell:

  • What RICS says underpinning costs. From £10,000 to £75,000 for a typical house, more for larger properties. RICS consumer guide, UnderpinningThe source says: "It's a lengthy, costly and disruptive procedure that can cost anywhere from £10,000 to £75,000 for a typical house, or even more for larger properties, depending on the extent."

Other methods rest on a single table, Mainmark's, and Mainmark sells one of them: mini piled underpinning £1,500 to £2,500 per metre and resin injection £800 to £1,500 per metre. One measurement from an interested party is not a price band, so treat those two as a starting point for questions.

On top comes the structural engineer at £50 to £100 an hour (the price guides say £50 to £90, GCS Contractors, Underpinning Cost per Metre UK 2026 says £50 to £100), the building control fee, and on a shared wall the party wall surveyors, which have their own page.

How long it takes

  • Monitoring takes a year. The ombudsman calls monitoring over 12 months sometimes reasonable, because it covers all the seasons. Financial Ombudsman Service, Handling a complaint like thisThe source says: "Monitoring over 12 months is sometimes reasonable because all the seasons are covered."
  • From first crack to finished repair. RICS: up to two years to investigate fully and rectify. RICS consumer guide, How can subsidence be fixed?The source says: "Solving subsidence can be a lengthy process that can take up to two years to investigate fully and rectify."

The building work is the short part: 3 to 5 weeks for most jobs according to MyJobQuote, and Mainmark's table puts 6 metres of wall at 6 days on site for mass concrete, 5-6 days for mini piles and 1-2 days for resin. The year of crack monitoring before it is what people do not expect.

What the insurer does

  • The excess. If the insurer accepts the claim you get your costs back minus the excess, which RICS says is commonly £1000. RICS consumer guide, Who pays?The source says: "A policy excess will probably be specified in your insurance documents, commonly £1000, in which case you will need to pay up to that amount before the costs are covered by insurance."
  • Why the excess is higher than for a leak. Damage from an escape of water can end up under the subsidence clause of the policy, which usually carries a higher excess. Financial Ombudsman Service, Escape of waterThe source says: "the claim would be considered under the subsidence peril clause, which usually involves a higher excess."
  • Just switched insurer: the previous one deals with it. Under the ABI Domestic Subsidence Agreement, a claim made eight weeks or less after the new policy started goes to the previous insurer. Financial Ombudsman Service, A change of insurerThe source says: "If the claim is made eight weeks or less from the start date of the current policy, the previous insurer deals with the claim."
  • Switched a year ago or more: the current one accepts it. A claim made one year or more after the policy started is accepted by the current insurer. In between, the two insurers share the cost. Financial Ombudsman Service, A change of insurerThe source says: "If the claim is made one year or more from the start date of the current policy, the current insurer accepts the claim."
  • Knowing about a crack is not knowing about subsidence. An insurer may void a policy when subsidence was known and not disclosed, but the ombudsman says being aware of cracking is not necessarily the same thing. Financial Ombudsman Service, A change of insurerThe source says: "But being aware of cracking is not necessarily the same as being aware of subsidence"
  • Patios, paths and terraces. Many policies do not cover subsidence damage to those unless the main residence is affected as well. Financial Ombudsman Service, Subsidence damage to other parts of the propertyThe source says: "Many insurance policies won't cover subsidence damage to parts of a property defined as buildings unless the main residence is also affected"

What I cannot give you is what cover costs after a claim, or for how long a claim follows the house. The Association of British Insurers would be the source, and its site refused an automated reader and then showed a bot check in the browser, which I did not try to get around. No source, no number. If a builder's guarantee is part of the repair, check what stands behind it on the guarantees page.

What it does to the value

  • What it does to value and premiums. The British Geological Survey names increased insurance premiums and depressed house prices among the costs of subsidence. It gives no percentage. British Geological Survey, Six ways to prepare your homeThe source says: "These costs could include increased insurance premiums, depressed house prices and in some cases, engineering works to stabilise land or property."

No open source I found puts a percentage on it, and I will not invent one. If a survey has flagged movement on a house you want to buy, what happens after a house survey covers the next step: get the specialist in first, and renegotiate on what they find.

The rules

  • Underpinning is building work in law. The Building Regulations 2010 list underpinning in the definition of building work. The Building Regulations 2010, regulation 3(1)(f)The source says: "work involving the underpinning of a building;"
  • So building regulations approval is needed. If you underpin all or part of the foundations, building regulations apply. Planning Portal, Is building regulations approval needed for underpinning?The source says: "If you need to underpin all or part of the foundations of your building, building regulations apply."
  • Each section is inspected before the concrete goes in. The excavation for each section is normally inspected by a design engineer and a building control surveyor before it is concreted. Planning Portal, Building Regulations: Methods and InspectionsThe source says: "The excavation for each section of underpinning will normally be inspected by a design engineer and a building control surveyor before it is concreted."
  • Planning permission is generally not needed. Maintenance on foundations generally does not require planning permission; listed buildings and designated areas should check first. Planning Portal, Underpinning, Planning PermissionThe source says: "Maintenance on foundations generally does not require planning permission."
  • A shared wall brings in the Party Wall Act. Underpinning a party structure is one of the rights the Act gives a building owner, and with it comes the duty to serve notice. Party Wall etc. Act 1996, section 2(2)(a)The source says: "to underpin, thicken or raise a party structure, a party fence wall, or an external wall which belongs to the building owner and is built against a party structure or party fence wall;"
  • That notice is two months. A party structure notice is served at least two months before the work begins. Party Wall etc. Act 1996, section 3(2)(a)The source says: "be served at least two months before the date on which the proposed work will begin;"
  • Digging near the neighbour, even when detached. Excavating within three metres of a neighbouring building, to below the bottom of its foundations, also falls under the Act. Party Wall etc. Act 1996, section 6(1)The source says: "a building owner proposes to excavate, or excavate for and erect a building or structure, within a distance of three metres measured horizontally from any part of a building or structure of an adjoining owner; and"
  • That notice is one month. For such an excavation the notice goes out at least one month before digging starts. Party Wall etc. Act 1996, section 6(5)The source says: "the building owner shall, at least one month before beginning to excavate, or excavate for and erect a building or structure, serve on the adjoining owner a notice indicating his proposals"
What this page is notThese are published figures, not a quote for your house. Most of the price sources do not say whether VAT is in; where one does, the table says so. Whether your movement is subsidence, and what stops it, is for a structural engineer or a chartered surveyor on site. The legislation quoted is that of England and Wales.

Sources, all opened on 20 September 2026: RICS consumer guide, Subsidence (Published date: 14 November 2022); Financial Ombudsman Service, Subsidence and other types of ground movement (the page shows no date); British Geological Survey, Six ways to prepare your home for climate change related subsidence (19/05/2021); British Geological Survey, Swelling and shrinking soils (the page shows no date); The Building Regulations 2010, regulation 3 (Latest available (revised) version); Planning Portal, Is building regulations approval needed for underpinning? (the page shows no date); Planning Portal, Underpinning, Building Regulations: Methods and Inspections (the page shows no date); Planning Portal, Underpinning, Planning Permission (the page shows no date); Party Wall etc. Act 1996, section 2 (Latest available (revised) version); Party Wall etc. Act 1996, section 3 (Latest available (revised) version); Party Wall etc. Act 1996, section 6 (Latest available (revised) version); MyJobQuote, How Much Does Underpinning Cost? (Last updated 17/09/26); Checkatrade, What are Underpinning Costs? (Page: last updated 31 March 2022; price tables: last updated May 2024); EMA Structures, How Much Do Basements and Underpinning Cost in London? (Published 14 July 2026); Mainmark UK, How much does underpinning cost in 2025? (Headed 2025; the page shows no publication date); Homebuilding & Renovating, How much does underpinning cost? A quantity surveyor explains (Last updated 24 October 2024); GCS Contractors, Underpinning Cost per Metre UK 2026 (the page shows no date). Tried and not counted: Association of British Insurers.

Frequently asked questions

How much does subsidence cost to fix?

It depends on the cause more than on the house. If a tree or a leaking drain is behind it, dealing with that is often the whole repair, and RICS estimates that fewer than 5% of properties with subsidence need underpinning. When they do, RICS gives £10,000 to £75,000 for a typical house and Homebuilding & Renovating gives £10,000 to £30,000 for a typical three-bedroom semi, with £50,000 or more for larger or more intricate jobs. With an accepted insurance claim your own bill is normally the excess, commonly £1,000 (RICS).

How much does underpinning cost per metre?

About £1,000 to £1,500 per metre of wall for traditional mass concrete. Mainmark's table gives £1,000 to £1,500 per linear metre, and EMA Structures, a London contractor, publishes around £1,500 per metre run before VAT, which is £1,800 with VAT. The big price guides say £1,500 "per m2", but their own worked examples come out at that rate times the metres of wall, so I read it as the same figure.

How long does underpinning take?

The work itself: 3 to 5 weeks for most jobs according to MyJobQuote, and Mainmark's table puts 6 metres of mass concrete at 6 days on site. The wait before it is longer. Cracks may be monitored for as long as 12 months, and RICS says solving subsidence can take up to two years to investigate fully and rectify.

Does subsidence always need underpinning?

No. RICS estimates that fewer than 5% of properties suffering from subsidence need it, and says the Institution of Structural Engineers recommends underpinning only as a last resort. Where tree roots are the cause the tree can be removed or managed, and where a leaking drain is washing soil away, repairing the pipework is usually enough.

When should I worry about subsidence?

RICS: there is rarely any cause for real concern unless cracks appear suddenly and are more than 3mm wide. Other signs it lists are new or expanding cracks in plaster or outside brickwork, doors or windows sticking for no reason, and new sloping of solid ground floors. The Financial Ombudsman Service adds that cracking in itself is not evidence of subsidence; what marks it is different parts of the building moving at different rates.

How much does subsidence devalue a property?

I have found no open source that gives a percentage, so I give none. The British Geological Survey lists depressed house prices and increased insurance premiums among the costs of subsidence, and that is as far as the sources go. Any figure you read elsewhere should come with where it was measured.

What is a subsidence excess in home insurance?

The part of a subsidence claim you pay yourself. RICS says it is commonly £1,000. The Financial Ombudsman Service notes that the subsidence clause of a policy usually carries a higher excess than the escape of water clause, which matters when a leak caused the movement.

Do I need building control or planning permission for underpinning?

Building control, yes: the Building Regulations 2010 name underpinning as building work, and each section is normally inspected before it is concreted. Planning permission is generally not needed for work on foundations, though a listed building or a designated area should check first (Planning Portal). On a shared wall the Party Wall etc. Act 1996 asks for a notice at least two months ahead.