The short answer: before you sign with a builder in South Australia, check four things. Their builder's licence is current on the Consumer and Business Services (CBS) public register. They will take out building indemnity insurance if your job needs council approval and costs $20,000 or more. The contract is in writing, with their business name and licence number on it. And the deposit is inside the legal limit. Once those boxes are ticked, choose on the things a licence can't tell you: their finished work, how they quote and who will actually run your job.
Below is each check in the order you'll meet it, with the official source for every rule. It applies to SA builders of every kind, for new homes, extensions and renovations alike. We're a licensed SA builder ourselves (BLD 360698), so we've added the questions we think every homeowner should ask.
How to check out a builder in 10 minutes
- Get their licence number and search it on the CBS Find a licence holder register. Check it's current and the name matches the quote.
- Check the CBS public assurances register, which SA.GOV.AU suggests for businesses where there have been official concerns about their work (SA.GOV.AU).
- Read their Google reviews, newest first, and look at how they describe the builder: turning up, communication, cleaning up, finishing on time.
- Look at their finished work: whole rooms or homes like yours, not just close-ups.
- Ask for a recent reference and call them.
1. Check the builder's licence
Builders must be licensed to carry out most types of domestic building work in SA, and there are significant penalties for unlicensed work (Law Handbook). The SA Government's advice is simple: ask to see the licence, then search the register (SA.GOV.AU, Choosing a builder).
- Search the name or licence number on the CBS Find a licence holder register.
- Check the licence is current and covers the type of work you want done.
- Make sure the name on the licence matches the business on your quote and contract.
- Ask the same question about anyone else on the job. Electricians and plumbers need their own licences too.
You can try it on us: ASP Build & Co holds SA Builder's Licence BLD 360698, issued by Consumer and Business Services.
2. Check their reputation and their finished work
A licence tells you a builder met the entry criteria. It doesn't tell you how they finish a job. SA.GOV.AU suggests checking the CBS public assurances register, which lists businesses where there have been official concerns about their work, asking for references from people who've had recent work done and checking the quality, and reading reliable reviews (SA.GOV.AU).
Ask to see completed jobs similar to yours, in photos or in person. A builder who has finished new homes should be able to show you whole homes, inside and out. Ours are in our portfolio, including three custom homes at Riverlea Park.
3. Confirm building indemnity insurance
In SA, building work contractors must arrange and pay for building indemnity insurance for any domestic building work that must be approved by council and costs $20,000 or more (SA.GOV.AU, Building indemnity insurance). That threshold rose from $12,000 on 10 November 2025 (Law Handbook).
- It protects you, and future owners, if the builder dies, disappears or becomes insolvent and the work isn't finished or defects need fixing.
- Defective work claims can usually be made up to 5 years from when the building work was completed.
- Building work can't start until the builder has taken out the policy and both you and the council have a copy of the certificate.
- Keep the certificate. It shows the builder's name and licence number, the insurer, the date issued and a description of the work insured.
4. Compare quotes on what's included, not just the total
Two quotes for the same job can look thousands of dollars apart and turn out to be quoting different things. Put them side by side and check:
| Check | Why it matters |
|---|---|
| Is it itemised? | A single lump sum makes it hard to see what's included or to compare like with like. |
| Who handles approvals? | Drafting, engineering, council or private certifier fees and insurance either sit in the quote or land on you. |
| Which trades are included? | Electrical, plumbing, waterproofing and tiling: in the price, or extra? |
| What's excluded? | Site works, landscaping, making good and fixtures you choose later are common gaps. |
| What's the timeframe? | A start date and finish date, or at least an estimate of the days the work will take. |
5. Read the contract before you sign
For domestic building work worth more than $20,000, the contract must be in writing and legible, set out all the terms, include the builder's details such as their business name and licence number, and be signed by both of you. You must also be given a signed copy with a prescribed notice called Form 1, "Your Building Contract: Your Rights and Obligations" (Law Handbook).
- Look for a start and finish date, or an estimate of how many days the job will take.
- Variations you ask for must be agreed in writing. Keep copies with the contract, and remember they can add cost.
- You have 5 clear business days after signing to cool off. To use it, give the builder written notice that you don't intend to be bound by the contract.
- Don't sign until you've read it, understood it and checked everything you discussed is in it. If something is unclear, ask the builder or Consumer and Business Services.
6. Keep the deposit and payments inside the rules
SA.GOV.AU says that for contracts of $20,000 or more, a deposit should be no more than 5% of the total (SA.GOV.AU). The Law Handbook sets out the advance payments the regulations allow: a deposit of $1,000 for work worth up to $20,000, or 5% for work over $20,000, plus some preliminary costs such as the indemnity insurance premium and professional services like engineering, drawing or surveying (Law Handbook).
After that, a builder can only ask for genuine progress payments for work already done, and you don't have to pay without a written request. SA.GOV.AU puts it plainly: once work has started, only pay for completed work when you receive an invoice.
7. Know the warranties you already have
Every domestic building work contract in SA carries statutory warranties: the work will be done to accepted trade standards and the agreed plans, with good and proper materials, in line with the law, with reasonable diligence, and the home will be fit to live in and suit the purpose you told the builder about. Proceedings for a breach must be started within 5 years of completion (Law Handbook). They apply even to small jobs under $20,000 (Law Handbook).
Questions to ask any builder
- Who will run my job day to day, and who do I call when I have a question?
- Which trades are your own team and which are subcontracted? Are they all licensed?
- Who looks after the approvals, the engineering and the indemnity insurance?
- How do you handle variations if I change my mind halfway through?
- What's the timeframe, and what usually causes delays on jobs like mine?
- Can I see finished work like this, or talk to someone you've built for?
Red flags worth walking away from
- No licence number on the quote, or a name that doesn't match the register.
- A deposit request above the legal limit, or payment asked for work that hasn't been done.
- Reluctance to put the price, the inclusions or the dates in writing.
- Pressure to sign today, or to start before the insurance certificate exists.
Smaller jobs under $20,000
Work under $20,000 counts as minor domestic building work. There's no legal requirement for a written contract or indemnity insurance, but the builder and trades must still be licensed and the statutory warranties still apply. Read any terms carefully and be wary of a large deposit (Law Handbook). A written quote and contract is still the sensible way to do it.
How we work at ASP Build & Co
We're a licensed SA builder (BLD 360698) working across Gawler and Adelaide's northern suburbs, and the inner south around Mitcham. Every project starts with a free consultation and a detailed, itemised quote with no hidden costs. Anthony is your one point of contact and coordinates every trade, approvals are managed as part of the job, and electrical work is done in-house by ASP Electrical Installations. See custom home builds, home extensions, bathroom renovations and kitchen renovations, or our pages for builders in Gawler, renovations in Salisbury and Elizabeth.
Common questions
How do I check if a builder is licensed in SA?
Ask for their licence number, then search it on the Consumer and Business Services 'Find a licence holder' register. Check it's current, covers the type of work and matches the business name on your quote and contract.
How much deposit can a builder ask for in South Australia?
The SA Government says that for contracts of $20,000 or more, a deposit should be no more than 5% of the total. The Law Handbook lists $1,000 for work up to $20,000. Builders can also ask up front for some preliminary costs, such as council approval, soil testing or the indemnity insurance premium.
When does a builder need building indemnity insurance in SA?
For domestic building work that needs council approval and costs $20,000 or more. Work can't start until the builder has the policy and both you and the council have a copy of the certificate.
Is there a cooling-off period on a building contract in SA?
Yes. You have 5 clear business days after signing a domestic building work contract to terminate it, by giving the builder written notice that you don't intend to be bound by it.
How do I check if a builder is good?
Start with the basics: a current licence on the CBS register in the business name on your quote, and no listing on the CBS public assurances register. Then look at finished work like yours, read recent reviews and call a reference. A builder who quotes in person, in writing and itemised is usually a good sign.
What should a builder's quote include?
An itemised price, what is and isn't included, who handles approvals, engineering and insurance, which trades are covered, and a timeframe. A builder who visits the site before quoting will usually give you a more reliable figure.
Related pages
Sources
- SA.GOV.AU, Choosing a builder (updated 10 November 2025)
- SA.GOV.AU, Building indemnity insurance (updated 19 February 2026)
- Consumer and Business Services SA, Find a licence holder
- Legal Services Commission of SA, Law Handbook: Building work contracts
- Legal Services Commission of SA, Law Handbook: Licensing of builders (revised 12 March 2026)
- Legal Services Commission of SA, Law Handbook: Minor domestic building work
Rules and published figures checked on 23 October 2026. Third-party cost ranges are not ASP Build & Co prices; we quote every job individually after a site visit.
