Greater London · England
Underpinning in Greater London
We arrange surveys and price underpinning throughout Greater London. Shrinkable clay is widespread in Greater London, and we take that into account before recommending a method.
Guide price from£1,250per metre of wall inc VAT
- Area
- Greater London
- Pricing region
- London
- Ground
- Shrinkable clay widespread
- Towns listed
- 32
What is the ground like in Greater London?
Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden trees.
Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
From first photo to finished repair
Engineer’s investigation
An independent chartered structural engineer studies the monitoring results, trial pits and soil tests, then decides whether underpinning is needed and which method suits. We can arrange the engineer if you do not already have one.
Design and approvals
The engineer produces drawings and calculations. We make the building control or building warrant application, and party wall notices are served where the law requires them, before any digging starts.
Crack repairs and handover
Once the new foundation has cured, cracks are stitched and repointed, inside walls are made good, and paths or patios disturbed by the dig are reinstated. You receive the building control completion paperwork for your records.
Symptoms that point to underpinning
- Movement continuing through more than one winter of monitoring
- One corner of the house visibly lower than the others
- A large tree nearby that cannot be removed or reduced
- Cracks that keep widening after the drains have been repaired
Guide prices for underpinning in Greater London
Prices in Greater London are worked out on London rates. They include VAT and are a starting point: access, the extent of the damage and whether an engineer or building control is involved all move the figure.
| Item | Guide price | Per |
|---|---|---|
| Mass-concrete underpinning | £1,250 – £1,900 | per metre of wall |
| Beam-and-base underpinning | £1,900 – £3,100 | per metre of wall |
| Mini-piled underpinning | £2,500 – £4,400 | per metre of wall |
| Engineer's design and building control feesest. | £1,000 – £3,100 | per scheme |
Methods for underpinning
Beam-and-base underpinning
A reinforced concrete beam is cast beneath or alongside the existing footing and carries the wall onto mass concrete bases at intervals. It spreads load well across variable ground and can mean less digging than continuous underpinning along the whole wall.
Best for: Longer runs of wall or heavier loads over variable ground
Mass concrete underpinning
The traditional method. Short sections under the wall are dug out in a set sequence, usually about a metre at a time, and filled with concrete before the next section is opened. It suits moderate depths and good access, and it needs little specialist plant.
Best for: Shallow failures on firm ground found at moderate depth
Mini-piled underpinning
Small-diameter piles are driven or bored down to firm ground and linked by a reinforced beam or needles that pick up the wall. Compact rigs fit through narrow access, and the method reaches depths that would be impractical to excavate by hand.
Best for: Deep soft ground, tree roots, or restricted access
Do you need approval for underpinning in England?
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Find underpinning in your Greater London town
- Croydon
- Barnet
- Ealing
- Newham
- Brent
- Bromley
- Enfield
- Wandsworth
- Lambeth
- Tower Hamlets
- Redbridge
- Southwark
- Hillingdon
- Lewisham
- Greenwich
- Hounslow
- Waltham Forest
- Haringey
- Havering
- Harrow
- Hackney
- Bexley
- Barking and Dagenham
- Islington
- Merton
- Camden
- Sutton
- Westminster
- Richmond upon Thames
- Hammersmith and Fulham
- Kingston upon Thames
- Kensington and Chelsea
Frequently asked questions
Why do houses in Greater London crack?
Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden trees. Ground movement here is more often linked to soils, drains and trees than to mining. Only an investigation on site can say why a particular building has moved.
How much will underpinning cost in Greater London?
On London rates, underpinning starts from about £1,250 per metre of wall, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
Will underpinning affect selling my house?
It needs explaining to buyers, but a properly documented scheme is far better than unresolved movement. Keep the engineer’s design, the building control completion certificate and any insurance paperwork. Lenders and surveyors will usually ask for these before agreeing a sale.
Do I need to tell my neighbours about underpinning?
In England and Wales you usually do. Underpinning a party wall normally needs two months’ notice, and excavating near a neighbour’s foundations needs one month’s notice under the Party Wall etc. Act 1996. Scotland and Northern Ireland have no equivalent Act, but agreeing the work in writing still helps.
Does underpinning need building control approval?
Yes, underpinning is building work and needs approval and inspections in England and Wales, a building warrant in Scotland, and council building control in Northern Ireland. Inspectors usually check the excavations before concrete is poured. We deal with building control as part of the job.