The short answer
Underpinning a house in the UK typically costs around £10,000–£35,000 for a domestic project, though a small section of one wall can start near £5,000 and full underpinning of a larger property can pass £50,000. The method drives most of the figure: traditional mass concrete underpinning is usually quoted at roughly £1,500–£2,500 per metre of wall, while mini-pile (piled) underpinning for difficult ground or deep foundations commonly runs £2,000–£4,000 per metre. On top of the build you pay for a structural engineer's report, Building Control approval and often a Party Wall Act 1996 surveyor. Because every figure depends on soil conditions, access, the cause of movement and how much of the structure needs support, the honest answer is always a range.
Underpinning cost depends mainly on the method your structural engineer specifies, how many linear metres of wall need support, the ground conditions and access. The figures below are typical UK ranges for guidance, not quotations.
Typical UK costs
- Small single-wall sectionfrom ~£5,000
- Typical domestic project£10,000–£35,000
- Mass concrete~£1,500–£2,500 / metre
- Mini-pile (piled)~£2,000–£4,000 / metre
- Professional / Building Control feesoften £2,000–£5,000+ on top
What drives the price
- Method: mass concrete is the lowest-cost route where ground is stable and depth is modest; mini-piling costs more but reaches stable strata under poor soil, trees or made-up ground.
- Linear metres: you largely pay per metre of wall supported, so underpinning one bay costs far less than the full perimeter.
- Access: tight rear gardens, no side access and hand-dig conditions add labour; machine access lowers it.
- Cause of movement: if subsidence is driven by a leaking drain or nearby tree, that root cause must be fixed too, which adds to the total.
- Depth: deeper foundations mean more excavation, temporary support and concrete per metre.
| Scope | Typical figure | Notes |
|---|---|---|
| Single wall / one bay (mass concrete) | £5,000–£12,000 | shallowest, simplest case |
| Several walls / part-perimeter | £12,000–£25,000 | depends on metres and depth |
| Full house (mass concrete) | £20,000–£40,000 | whole perimeter supported |
| Piled scheme (poor ground) | £25,000–£50,000+ | mini-piles to stable strata |
Indicative UK figures for guidance. Sources: Checkatrade underpinning cost guide and RICS subsidence guidance.
Fees that sit alongside the build
The contractor's price is rarely the whole cost. Most jobs need a structural engineer to diagnose the movement and design the scheme — typically a few hundred pounds for an initial report and more for a full design and site supervision. Underpinning is notifiable work, so you pay Building Control fees to your local authority or an approved inspector, and the foundations are inspected as the work proceeds. If your home is semi-detached or terraced, the Party Wall etc. Act 1996 usually applies, which can mean serving notice on neighbours and appointing surveyors. Where a leaking drain or tree is the cause, drainage repairs or arboricultural work add further cost.
How the method changes the price
The single biggest swing in cost comes from the method your structural engineer specifies, and that is dictated by the ground, not by preference. Traditional mass concrete is the lowest-cost route, used where stable bearing soil sits at a reachable depth and the wall can be supported in sequenced bays. Beam-and-base sits in the middle, casting reinforced concrete pads at firm points and spanning beams between them where the ground is patchy. Mini-piling is the most expensive, driving piles down to a deep stable stratum where the near-surface soil is weak, made-up, or dried by a large tree on shrinkable clay. A whole house on good ground might be done in mass concrete for £20,000–£40,000; the same house on poor ground needing piles can pass £50,000. Resin injection is a separate, lower-disruption ground-improvement option for certain soils, but it is not a deep foundation and a structural engineer must confirm it is appropriate.
| Method | Per metre | When the engineer chooses it |
|---|---|---|
| Mass concrete | £1,500–£2,500 | stable ground at modest depth |
| Beam-and-base | £1,800–£3,000 | variable / patchy ground |
| Mini-pile (piled) | £2,000–£4,000 | weak or deep ground, trees on clay |
Indicative UK figures for guidance. Sources: Checkatrade underpinning cost guide and structural engineering practice.
Region, timeline and what to confirm
Where you live moves the figure: London and the South East typically carry a premium over the national average, driven by higher labour and overhead costs and more frequent need for restricted-access working. Timeline matters too — underpinning is dug and filled in short alternating bays so the building is never unsupported, and each bay must gain strength before the next is done, so even a modest scheme takes several weeks rather than days. Before agreeing any price, confirm the scope in writing: how many linear metres are supported, the method and depth, whether the structural engineer's fees, Building Control charges and any Party Wall surveyors are included, and whether making good — reinstating floors, drives, paths and decoration — is in the quote or extra. A lower headline that excludes the engineer, the fees or the reinstatement is not really lower. Get every contractor to quote on the same written specification so you are comparing like for like.
It also helps to understand why two quotes for the same house can differ. Underpinning is not a commodity product: contractors price the labour content of your ground and access, the depth their trial holes reveal, and the risk they are carrying on a structural job that must keep the building safe throughout. A firm that has inspected the foundation and allowed properly for spoil removal, temporary support and reinstatement will quote differently from one that has assumed the easiest case. The most reliable comparison is to give each contractor the structural engineer's written scheme — the method, the depth, the metres and the inclusions — and ask them to price that exact specification. A quote built on the engineer's design, rather than a contractor's guess at what might be wrong, is the one you can trust, and it stops the cost drifting upward once the bays are open and the real conditions are exposed.
One more thing worth understanding is why two surveyors looking at the same crack can arrive at very different totals. The figure is driven far less by the visible damage than by what the trial holes and soil investigation reveal underground: a shallow Victorian footing on firm gravel needs a modest mass-concrete scheme, while the same crack over deep shrinkable clay with a mature tree nearby can demand piles two or three times deeper, at a multiple of the cost. That is why a number quoted before any ground investigation is close to meaningless, and why the engineer's diagnosis is the single most valuable spend in the whole project. It also explains the wide published ranges: they are averaging across ground conditions that genuinely differ by a factor of three or more. The sensible way to read any headline price for underpinning a house, then, is as the starting point of a conversation with a structural engineer, not as a quote you can hold a contractor to. Until the cause is identified and the affected length measured, the only honest answer to what it will cost is a range, and the engineer's report is what turns that range into a figure you can actually budget against.
Frequently asked questions
How much does it cost to underpin a whole house?
Underpinning a full house in the UK typically costs around £20,000–£40,000 with traditional mass concrete, and more where mini-piling is needed for poor ground. The figure depends on the perimeter length, foundation depth and access.
Is underpinning ever cheaper than rebuilding?
For most subsidence cases underpinning is the lower-cost and less disruptive route compared with demolition and rebuild, because it stabilises the existing structure. A structural engineer will advise whether repair, underpinning or rebuild is the right call for your property.
Does the quoted price include making good?
Not always. Confirm whether reinstating floors, drives, paths and decoration after excavation is in the quote, as making good can add a meaningful sum on top of the structural work.
Sources & further reading
- Checkatrade — underpinning cost guide
- RICS — subsidence and your home
- Planning Portal — Building Regulations and structural work
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation.