PlanSA and development approval
South Australia assesses building work under the Planning, Development and Infrastructure Act 2016, with applications lodged through the PlanSA portal. Development approval has two limbs: planning consent and building consent. Straightforward like-for-like maintenance is often exempt, but underpinning sits in awkward territory because it changes the structural support of the house, and structural work generally needs building consent even where planning consent is trivial. Whether your specific job needs approval depends on its scope and your council's reading of the rules, so check with your council or an accredited building certifier before work starts rather than after. Many underpinning contractors handle the application as part of the job; confirm who is lodging it and get the approval number in writing. Our regulations hub shows how SA compares with the other states.
Builder licensing through CBS
Building work contractors in SA are licensed by Consumer and Business Services (CBS) under the Building Work Contractors Act 1995. A legitimate underpinning or restumping firm holds a building work contractor licence, and the work itself must be overseen by a registered building work supervisor named against that licence. The licence number should appear on quotes and contracts. SA also has contract rules for domestic building work, including cooling-off rights and progress payment limits, so read the contract against the CBS guidance at cbs.sa.gov.au before signing. Since most underpinning jobs run $10,000–$40,000, you are well inside the territory where these protections matter.
Building indemnity insurance
Where domestic building work requires approval and the contract price is over the threshold, the contractor must take out building indemnity insurance before starting, and both you and the council must receive the certificate. The threshold was $12,000 for many years and rose to $20,000 from November 2025. The policy protects you if the builder dies, disappears or becomes insolvent, with defect claims possible for up to five years. It is the contractor's job to arrange it; your job is to sight the certificate before handing over money beyond the permitted deposit. Note that owner-builders cannot take this insurance out on their own work, which becomes relevant if you later sell a house you underpinned yourself, so keep every scrap of engineering and approval paperwork if you go down that road.
Engineering on reactive clay
Adelaide sits on some of the most reactive clay soils in the country, the kind that swell in winter and shrink hard through dry summers, which is why cracked brickwork is close to a local tradition. That makes independent engineering more important here, not less. A footing investigation and engineer's report ($600–$1,200, with design work up to $2,500) plus a soil test ($400–$1,000) tells you whether movement is seasonal or progressive, and what fix suits your soil profile. Councils and certifiers will expect engineering documentation for structural consent, and a design matched to the clay matters more than the brand of underpinning method a salesperson prefers.
On reactive clay, a quote written without a soil test or engineering input is a guess. Get the engineering first, then quotes against the engineer's scope, and compare like with like.
Checking a licence
CBS runs a free public register of occupational licences. Search the contractor's licence number online, confirm the trading name matches your contract, check the licence is current and covers building work, and note any conditions. If you are still shortlisting, our Adelaide directory lists underpinning and foundation repair specialists, and our underpinning guide explains what a well-run job looks like from first crack to final certificate. When the work finishes, file the approval documents, the engineer's design and inspection notes, the insurance certificate and the contract together: that bundle is what a buyer's conveyancer will ask for, and it is far easier to keep now than to reconstruct in ten years.
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Common questions
Does underpinning need development approval in SA?
Structural work generally needs building consent through the PlanSA system, though minor like-for-like maintenance can be exempt. The boundary depends on scope and council interpretation, so confirm with your council or an accredited certifier before starting.
What insurance should my SA builder have?
Building indemnity insurance is compulsory for approved domestic building work over the threshold, which rose from $12,000 to $20,000 in November 2025. The contractor arranges it and must give you the certificate before work starts.
Who licenses builders in South Australia?
Consumer and Business Services (CBS). Contractors hold a building work contractor licence and the work must be supervised by a registered building work supervisor. You can check any licence free on the CBS public register.
Is cracking normal in Adelaide houses?
Seasonal hairline cracking on reactive clay is extremely common and often cosmetic. Cracks under 1 mm are usually monitoring territory; cracks over 5 mm, or ones that keep widening, deserve a professional assessment before anyone quotes you for underpinning.