Underpinning in Sydney — questions and answers
Short answers on what underpinning involves in Sydney: who may do the work, which council rules apply where, which cracks matter and how enquiries here are handled. The answers cite NSW legislation, councils' own documents and CSIRO, and this site sets no prices.
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How much does underpinning cost in Sydney?
We set no price here, and no government source we read publishes one. Businesses publish bands that depend on the method; the costs page gives the two we could source twice, with the dates read.
Why do two quotes for one house differ?
Because the job is not always the same. A quote turns on the cause, how much of the house has moved, how the footing can be reached and the method chosen, and CSIRO says remediation of footings is generally the realm of a specialist consultant. Ask each provider which cause its quote is built on.
Underpinning in Sydney
What the law gives a homeowner before the digging starts
Four protections in NSW's home building law, each with the figure the law itself states.
Proof of cover before the deposit
A$20,000
the contract value above which home building compensation cover is required, inclusive of GST
Cover is a last resort if the contractor cannot meet their legal duties. Ask for the certificate for your property first.
Source: Home Building Regulation 2014 (NSW) and icare, Home Building Compensation Fund · read
How long a builder answers for a footing
6 years
the statutory warranty period for a major defect, and the Act names foundations and footings as a major element
Other defects carry a shorter period, and the period starts when the work is complete.
Source: Home Building Act 1989 (NSW) · read
A limit on the deposit
10%
the most a deposit for residential building work can be, as a share of the contract price
A deposit is a payment before work starts. If the job needs cover, the contractor may not ask for it until the certificate is given to you.
Source: Home Building Act 1989 (NSW) · read
Time to change your mind
5 clear business days
how long after you are given a signed copy of a contract above the prescribed amount you can rescind it by written notice
Whether a given contract is above the prescribed amount turns on its price, and the contract itself says which.
Source: Home Building Act 1989 (NSW), section 7BA · read
Each figure names its source and the date it was read. The Home Building Act and its Regulation are the law; the agency pages are guidance. None of this is a quote for your house.
Process
Where does my enquiry go?
To one independent provider covering your part of Sydney, who gets in touch to see the house and quote. You pay us nothing, and if no provider can take the job we tell you.
How do I check a contractor's licence?
Ask for the licence number and the categories it covers, and ask which one the job is done under. The Home Building Regulation lists underpinning or piering as a trade category and a licence is needed above A$5,000; restumping is not a category of its own.
Timing
How quickly can someone get to me?
We can't promise a time: it turns on the provider's bookings and on any approval the work needs.
Can I wait and watch a crack?
Sometimes. CSIRO says cracking from settlement during construction usually stays as it is once the settling stops, while cracking from local shear or erosion usually keeps developing until the cause is remedied. It says monitoring of cracks in walls and floors should always be treated seriously.
Permits and approvals
Do I need council approval to underpin?
It depends on the job, the land and the council. Some Sydney councils attach report requirements to land on their landslide or acid sulfate soils maps, a certifier or the council can say what a given house needs, and no source we read says that underpinning as such needs or does not need a development application.
Source: Warringah LEP 2011 cl 6.4; The Hills LEP 2019 cl 7.6; Bayside LEP 2021 cl 6.1; Inner West Council DA Lodgement Guide (May 2026); read 21 September 2026
Service area
Which suburbs do you cover?
Anywhere in the councils of Greater Sydney that we list. Five suburbs have a page, Beacon Hill, Castle Hill, Mascot, Marrickville and Penrith, each written around what a council's own controls or the state's mapping show for it. Others, such as Blacktown and Maroubra, are covered on the same terms.
Do you do the underpinning yourselves?
No. A marketing company runs this site. It passes each enquiry to an independent local provider, who inspects the house, quotes and does the work. We hold no building licence, and we own no plant.
Thanks — we have your enquiry. Someone will be in touch shortly. Prefer to talk now? Call (02) 9072 0403.
Last reviewed · Updated · First published