Cost guides › Underpinning
Australia
Underpinning and foundation repair cost
Underpinning to stabilise a sinking section of a house typically costs $12,500 including GST for 8 piers or underpinning points, with most jobs between $9,750 and $16,300. The price includes a structural engineer's inspection and report, the piers, excavation and installation, and an allowance for approvals and monitoring. Shallow concrete underpinning on firm ground is around $9,600; deep piles or micropiles for reactive clay or filled sites are nearer $16,800.
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Cost by region
| Location | Basic | Mid-range | Premium |
|---|---|---|---|
| Australian Capital Territory | $9,950 | $13,000 | $17,400 |
| Western Australia | $9,750 | $12,700 | $17,100 |
| New South Wales | $9,650 | $12,600 | $16,900 |
| Northern Territory | $9,700 | $12,600 | $16,900 |
| Queensland | $9,550 | $12,500 | $16,700 |
| Victoria | $9,550 | $12,500 | $16,700 |
| South Australia | $9,300 | $12,200 | $16,300 |
| Tasmania | $9,100 | $12,000 | $16,000 |
What's included
Mid-range
- Inspection by a structural engineer and a report specifying the repair
- 8 piers or underpinning points (screw piles or concrete pad-and-beam sections), materials and equipment
- Excavation beside the footing at each point
- Installing and loading each pier or section under the existing footing, then backfilling
- Removal of spoil and clean-up
- Allowance for permit or certification costs and monitoring after the work
What affects the cost
Underpinning method
Mass concrete or pad underpinning digs under the footing and fills with concrete, which suits shallow problems on firm ground. Screw piles are wound down to a set load and suit many clay sites with less excavation. Deep bored piles, micropiles or resin injection are used for deep unstable ground and cost the most.
Soil type and depth to firm ground
Reactive clay that swells when wet and shrinks when dry is behind a lot of slab and footing movement. The deeper the stable layer, the longer the piers and the higher the cost. The engineer may ask for a soil test to decide.
Slab or stumps
Slab-on-ground homes and brick footings are underpinned. Homes on stumps are usually restumped instead, replacing rotted timber or failed stumps with concrete or steel and relevelling the floor. That is a different job and is not what these figures cover.
Access
Clear access along the affected wall keeps costs down. Working under decks, next to a boundary, inside the house or where machines cannot get in means more hand digging.
The cause of the movement
Leaking pipes, poor stormwater drainage, garden watering against the footing and large trees are common causes. Fixing the drainage may be needed alongside or even instead of underpinning, and that plumbing work is not included here.
Making good
After the house is stabilised, cracked brickwork, plaster, tiles and sticking doors need repair. That cosmetic work is priced separately.
How to save
- Get an independent structural engineer's report before calling contractors, so every quote prices the same method and number of piers.
- Fix leaking pipes and stormwater problems first and monitor the cracks; minor seasonal movement may not need underpinning.
- Get at least three quotes from licensed builders who specialise in underpinning, and ask for the warranty terms in writing.
- Keep trees and heavy watering well away from the footings in future, so you are not paying to fix the same wall again.
Grants, tax and rules
Licensed builders and approvals
Underpinning is structural work: it should be designed by a structural engineer and carried out by a licensed builder where your state requires it. It usually needs a building permit or approval, which the contractor or engineer typically arranges. Any plumbing or drainage repairs must be done by a licensed plumber.
Home insurance
Cover for ground movement varies widely and is often limited, especially for gradual movement. Check your policy wording before starting work, and contact your insurer first if the damage followed a sudden event such as a burst pipe or storm.
GST
Quotes to households include 10% GST, and so do our figures.
Frequently asked questions
How much does underpinning cost in Australia?
For 8 piers along the affected part of a house, expect around $12,500 including GST and the engineer's report. Shallow concrete underpinning is about $9,600, and deep piles for difficult soils are nearer $16,800. A whole house costs considerably more.
What is the difference between underpinning and restumping?
Underpinning strengthens or deepens the footings under a slab or brick walls. Restumping replaces the stumps that a raised timber-floored house sits on, usually swapping old timber for concrete or steel, and relevelling the floor.
What are the signs that a house needs underpinning?
Stepped cracks in brickwork, cracks that keep growing or reopen after repair, doors and windows jamming, sloping floors and gaps opening at skirting boards or cornices. Some seasonal cracking on clay sites is normal, which is why an engineer's assessment matters.
Do I need an engineer before underpinning?
Yes. A structural engineer should confirm the cause and specify the method, depth and number of piers. Without that, contractors may quote very different solutions that are hard to compare.
How long does underpinning take?
A partial job on one wall usually takes a few days to a couple of weeks, depending on the method and access. Screw piles are generally quicker than concrete underpinning, which needs curing time.
Will underpinning affect selling my house?
Documented, engineer-designed underpinning with a certificate and warranty reassures buyers. Unresolved cracking is much harder to sell, so keep all reports, approvals and warranty papers.
How this estimate is calculated
Work hours: 96 · Labour: $4,138 · Materials: $7,249
Sources: ABS Employee Earnings and Hours, Australia; Regione Toscana, Prezzario dei Lavori 2026 (CC BY 4.0); ECB exchange rates.