The short answer
Underpinning is usually priced per linear metre of wall supported, and the rate depends on the method. Traditional mass concrete underpinning is commonly quoted at around £1,500–£2,500 per metre, beam-and-base underpinning at roughly £1,800–£3,000 per metre, and mini-pile (piled) underpinning at about £2,000–£4,000 per metre. Linear metre means the length of wall along the foundation, not the area or footprint. So a job is broadly the per-metre rate multiplied by the number of metres needing support, plus fixed costs that do not scale with length — the structural engineer, Building Control, any Party Wall surveyors and making good afterwards. Because those fixed costs are spread across the job, very short runs can look expensive per metre. The rate within each band is driven by foundation depth, access, soil and region.
Pricing by the metre is how contractors quote, but the headline rate hides depth, access and fixed professional costs. The figures below are typical UK ranges for guidance, not quotations.
Typical UK per-metre rates
- Mass concrete~£1,500–£2,500 / metre
- Beam-and-base~£1,800–£3,000 / metre
- Mini-pile (piled)~£2,000–£4,000 / metre
- Plus fixed costsengineer, Building Control, party wall
- RegionLondon / South East premium
What a metre of underpinning includes
- Length of wall, not area: linear metre is the run of foundation supported. A 5-metre wall at £2,000/m is roughly £10,000 of structural work before fixed costs.
- Depth changes the rate: deeper foundations mean more excavation, temporary support and concrete per metre, pushing you toward the top of each band.
- Access: hand-dig and carry-out conditions cost more per metre than machine-accessible sites.
- Soil: poor ground may rule out mass concrete and force the higher piled rate.
| Method | Per linear metre | When used |
|---|---|---|
| Mass concrete | £1,500–£2,500 | stable ground, modest depth |
| Beam-and-base | £1,800–£3,000 | spans weak spots between bases |
| Mini-pile | £2,000–£4,000 | poor ground, deep strata, trees |
Indicative UK figures for guidance. Sources: Checkatrade underpinning cost guide and structural engineering practice.
Why short runs look dear per metre
The per-metre rate covers the structural work, but every job also carries fixed costs that do not shrink with length: the structural engineer's diagnosis and design, Building Control fees, any Party Wall Act surveyors, mobilising the contractor, and reinstating floors, drives and decoration. On a long run these spread thinly; on a one- or two-metre section they make the effective cost per metre look high. That is normal and not a sign of overcharging. When comparing quotes, look at the total for the same specified scope — the same metres, the same method, the same inclusions — rather than the headline per-metre figure alone.
What moves the rate within each band
Two quotes for mass concrete can both be honest yet sit at opposite ends of the £1,500–£2,500 band, because several factors push the per-metre rate up or down. Depth is the biggest: a foundation that must reach a metre deeper means much more excavation, temporary support and concrete per metre. Access is next — a site where a mini-digger reaches the wall is cheaper per metre than one where everything is hand-dug and barrowed out. Soil can rule a method out entirely, forcing a jump from the mass concrete band to the piled band. Run length spreads the fixed costs: a long continuous run is more efficient per metre than several short, separated sections. And region applies a premium in London and the South East. Understanding these is what lets you judge whether a higher per-metre figure reflects a genuinely harder job or simply a higher margin.
| Factor | Pushes the rate |
|---|---|
| Greater foundation depth | up |
| Restricted / hand-dig access | up |
| Poor soil (forces piling) | up — different band |
| Long continuous run | down per metre |
| London / South East | up |
General UK guidance. Source: Checkatrade underpinning cost guide.
Turning a per-metre rate into a real budget
To estimate a job, take the linear metres of wall your structural engineer says need support, multiply by the per-metre rate for the specified method, then add the fixed costs that every job carries regardless of length: the engineer's diagnosis and design, Building Control fees, any Party Wall surveyors, contractor mobilisation, spoil removal and making good. For example, a 6-metre run in mass concrete at £2,000/m is £12,000 of structural work, plus perhaps a few thousand more in fixed costs — so a realistic total might be £14,000–£17,000. Crucially, the metres figure should come from the engineer's assessment of what is actually affected, not a contractor's assumption, because most schemes are partial. Build the estimate from the diagnosed scope and the right method, and the per-metre rate becomes a useful tool rather than a misleading headline.
A useful sense-check when reading a per-metre quote is to ask what the rate assumes about depth, because depth is the variable most often left vague. A figure quoted without a stated depth is really only half a price: the same wall underpinned to a metre will cost far less per metre than the same wall taken down to two and a half metres, because the excavation, temporary support and concrete all scale with how far below the existing footing the new foundation must reach. Once the structural engineer has dug a trial hole and set the design depth, the per-metre rate becomes meaningful and comparable between contractors. Until then, treat any headline rate as indicative only. The same applies to whether the rate is for the structural work alone or includes the surrounding costs — two quotes at the same per-metre figure are not equal if one includes making good and the other does not.
The per-metre rate is genuinely useful for sense-checking a quote, but only if you also pin down the depth assumption baked into it, because depth is the hidden variable that makes two metre rates incomparable. A quoted rate of, say, £2,000 a metre for a shallow scheme down to firm ground at a metre or so is a very different proposition from £2,000 a metre quoted before anyone has confirmed how deep the firm ground actually is. On shrinkable clay near a tree, the foundation may need to reach two or three times deeper, and the real per-metre cost rises accordingly because there is more to excavate, support, fill and inspect. So when you collect metre rates from different contractors, the like-for-like comparison only holds if each is pricing the same design depth on the same method — otherwise the lowest rate may simply be assuming the shallowest, most optimistic dig. The way to keep the comparison honest is to take the depth from the structural engineer's design rather than from the contractor's assumption, give every contractor that same depth and method, and then compare their metre rates. Read that way, the per-metre figure is a reliable tool; read in isolation, it can mislead.
Frequently asked questions
What does underpinning cost per metre?
Mass concrete is typically £1,500–£2,500 per linear metre, beam-and-base around £1,800–£3,000, and mini-pile about £2,000–£4,000. The rate within each band depends on foundation depth, access, soil and region.
Is underpinning priced per linear metre or per square metre?
Most domestic underpinning is priced per linear metre of wall supported. Some contractors or methods reference footprint area, so always confirm the unit and that professional fees and making good are included before comparing quotes.
Why is a short run of underpinning expensive per metre?
Because fixed costs — engineer, Building Control, party wall surveyors, mobilisation and making good — do not shrink with length, so they make a one- or two-metre job look dear per metre. Compare the total for the same scope instead.
Sources & further reading
- Checkatrade — underpinning cost guide
- RICS — subsidence and foundations guidance
- Planning Portal — Building Regulations: structure
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation.