Subsidence is when the ground beneath your home collapses or starts to sink, causing problems to the foundation and structural issues. This puts a strain on one side of the property’s structure, which causes cracks to appear.
Changes in the soil cause. This can be the result of natural processes such as weather changes or water changes that causes soil to swell or shrink as well as man-made causes such as historic mine shafts, improper ground preparation or bad foundations themselves.
Regardless of the reason, underpinning is used to support the foundations. This is done by strengthening, repairing on increasing the depth of the foundation so that the footing is on more supportive soil.
This article will cover the costs you can expect to pay to exterminate fleas and other factors that can affect the cost.
Average Cost
We worked with a professional quantity surveying to price up underpinning of varying depths. The easiest way to figure out to to the cost is to figure out the depth of underpinning needed.
| Underpinning Depth | Cost per m² |
|---|---|
| 0.9m | £510 / m² |
| 1.5m | £700 / m² |
| 2m | £820 / m² |
| 3m | £920 / m² |
| 4m | £1000 / m² |
A detailed cost of the items that go into the underpinning is as follows:
| Item | Cost per m³ labour + plant | Cost per m³ materials | Cost per m³ total |
|---|---|---|---|
| Excavating; max depth not exceeding 0.25m | £61 | £0 | £61 |
| Excavating; max depth not exceeding 1m | £67 | £0 | £67 |
| Excavating; max depth not exceeding 2m | £82 | £0 | £82 |
| Disposal off site | £27 | £23 | £50 |
| Filling to excavations using excavated material | £14 | £0 | £14 |
| Concrete - C20 | £62 | £125 | £190 |
| Item | Cost per m² Labour | Cost per m² Materials | Total Cost per m² |
|---|---|---|---|
| Formwork; not exceeding 1m deep | £7 | £28 | £35 |
| Formwork; not exceeding 2m deep | £8 | £29 | £37 |
| Formwork; not exceeding 4m deep | £10 | £29 | £39 |
| Item | Labour Cost per Tonne | Material Cost per Tonne | Total Cost per Tonne |
|---|---|---|---|
| Rebar | £950 | £920 | £1870 |
| Item | Labour Cost per m² | Material Cost per m² | Total Cost per m² |
|---|---|---|---|
| One brick thick; brickwork | £54 | £65 | £119 |
Factors That Affect the Cost
Thickness of Wall Structure
For depths under 4m, only one brick thickness is likely needed. After that, you’d need to go to two bricks thick, which will add extra brick cost.
Domestic vs Commercial Project
Because underpinning is specialist work, contractors may charge higher to arrange works on smaller domestic projects.
Location
Areas in the south of England and London will be higher than in other parts of the country. The prices quoted in the table above apply for the South East or Outer London area. The adjustments below can be used to calculate costs in your area.
Region % Adjustment
South East (Southampton, Oxford, Kent, Outer London) 0
Inner London +4%
South West (Bristol, Exeter) -4%
West Midlands (Birmingham) -10%
East Midlands (Northampton, Nottingham, Leicester) -10%
East Anglia (Cambridge, Norwich, Ipswich) -5%
North West (Liverpool, Manchester) -12%
Yorkshire and Humberside (Leeds, Sheffield) -11%
North East (Newcastle, Sunderland) -10%
Scotland (Edinburgh, Glasgow) -6%
Wales (Cardiff, Swansea) -9%
Northern Ireland (Belfast) -12%
Get Pricing on Underpinning Near You
We’ve done our best to give you a good idea of what you can expect to pay for underpinning.
However, our guides are not a substitute for a fixed quote specifically for you.
We work with all the best underpinning specialists ready to price your job. Get free, no-obligation quotes in your local area and compare prices using the form below.
- Compare Multiple Quotes & Save Up to 40%
- Certified & Vetted Contractors
- Free & No Obligation
- Local Underpinning Experts Near You
About the Author
Alex Johnson is a qualified quantity surveyor and writer with a passion for conducting original research and uncovering the true cost of jobs. His cost data has been referenced by EDF Energy and the Scottish Government.