Questions to ask a builder before you sign
Twenty five questions to put to every builder on your shortlist, what a good answer sounds like, and a checklist to tick off before you sign.
Before you sign with a builder, ask for their licence number and check it, the home warranty insurance certificate, whether the contract is fixed price or cost plus, what the provisional sums add up to, the deposit and payment stages, the start date and build time, who supervises the site, how variations are handled and priced, and for recent references.
Licence and insurance questions
Start here, because a wrong answer ends the conversation.
- "What is your licence number, and whose name is it in?" Check it on your state's register and make sure the name matches the quote. Our licence check guide links every register.
- "Does your licence class cover this job?" A trade licence does not cover an extension or a new home.
- "Will you give me the home warranty insurance certificate before I pay a deposit?" In NSW, WA and the NT it is illegal to take a deposit before the certificate is given where cover is required. See the state thresholds.
- "Can I see certificates of currency for public liability and contract works insurance?" These are separate from the licence and from home warranty insurance.
Good answer: numbers and certificates offered without fuss. Warning sign: "we'll sort the insurance once we start".
Contract and price questions
- "Is this a fixed price or cost plus contract?" Fixed price suits most homes. In Victoria, cost plus is generally illegal below $1 million. Read our contracts guide.
- "Which standard contract will you use?" Industry association and regulator contracts are widely used and easier to get advice on than a builder's own document.
- "What do the provisional sums and prime cost items add up to?" A large total means the price is less fixed than it looks.
- "What is excluded?" Ask for the exclusions list in writing: site costs, landscaping, driveways, fencing and appliances are common.
- "Does the price include GST, and is there a rise and fall clause?"
Deposit and payment schedule questions
- "How much deposit do you need?" Compare the answer to your state's cap below.
- "What are the payment stages, and what work must be finished at each one?" Payments should match work done, not time on site.
- "Can an independent inspector check each stage before I pay?" NSW Government guidance puts an independent stage inspection at about $250 to $500 each.
| State | Maximum deposit on a typical home job |
|---|---|
| QLD | 5% for jobs of $20,000 or more |
| NSW | 10% |
| VIC | 5% for contracts of $20,000 or more |
| WA | 6.5% for contracts of $7,500 to $500,000 |
| SA | 5% for jobs of $20,000 or more |
| ACT | No statutory cap |
| TAS | 5% for contracts of $50,000 or more |
| NT | 5% |
As at 26 October 2026. Smaller contracts have higher caps in some states, and off-site prefabrication can allow up to 20% in Queensland, WA and Tasmania.
Timeline and supervision questions
- "When can you start, and how long will the build take?" Ask for both dates in the contract, and how the builder allows for wet weather.
- "How many jobs are you running right now?" A builder stretched across too many sites is a common cause of delays.
- "Who will be on site day to day, and who is my contact?" Get a name and a phone number, and ask how often the licensed builder visits.
- "Which work do you subcontract?" Most builders use subcontractors. You want to know who manages them and that licensed trades do licensed work.
- "How will you keep me updated?" Weekly updates and photos are a reasonable request.
Variations, defects and warranty questions
- "How do you handle variations?" The right answer is "in writing, priced, and signed before the work is done". That is the law in Queensland, NSW and Victoria.
- "What is your margin on variations and on PC and PS overruns?" Get the percentage in the contract.
- "What happens at handover, and how long is the defects period?" Ask how defects are reported, who fixes them and how fast.
Statutory warranties apply on top of anything the builder offers. In NSW they run 6 years for major defects and 2 years for other defects, and in Tasmania 6 years from practical completion.
Approval and certifier questions
- "Who applies for the approvals, and who certifies and inspects the work?" The builder often organises this. Make sure the quote says who pays the approval and certifier fees, and that you know who the certifier is and how to reach them.
Each state uses different names for the same steps, so it helps to know what to listen for:
| State | What you need | Who issues it |
|---|---|---|
| QLD | Building approval | A licensed building certifier, usually private |
| NSW | Development consent plus construction certificate, or a complying development certificate | Council or a registered certifier; you appoint the principal certifier |
| VIC | Building permit (plus a planning permit if needed) | A registered building surveyor you appoint, or the council |
| WA | Building permit | The local government permit authority |
| SA | Development approval (planning consent plus building consent) | Council, an assessment panel or an accredited professional |
| ACT | Building approval (plus a DA unless exempt) | A licensed building surveyor you appoint |
| TAS | Building permit | Council permit authority, after a building surveyor's certificate of likely compliance |
| NT | Building permit | A registered building certifier |
In Victoria a builder cannot appoint the building surveyor for you, and in the ACT a contract for a house cannot give the builder power to choose or remove the certifier. If a builder insists on picking the certifier, ask why.
Reference and track record questions
- "Can I speak to two or three recent clients with a similar job?" Ask them about the budget, the timeline and how problems were handled.
- "Can I see a finished job and one in progress?" A tidy current site says a lot.
- "Have you had a dispute go to the regulator or tribunal?" Then check the regulator's register for warnings or disciplinary action yourself.
- "How long has the business traded under this name?" Check the ABN and company name match the licence.
Printable checklist: before you sign
Tick each one off before you sign. Every builder we list has had their licence checked, but the rest is on you.
| Check | Done |
|---|---|
| Licence current, class fits the job, name matches the contract | ☐ |
| Home warranty certificate received (if required in your state) | ☐ |
| Public liability and contract works certificates of currency seen | ☐ |
| Contract type known (fixed price or cost plus) and standard form used | ☐ |
| PC and PS totals added up; exclusions list read | ☐ |
| Price includes GST; any rise and fall clause understood | ☐ |
| Deposit within the state cap | ☐ |
| Payment stages tied to completed work | ☐ |
| Start date, build time and site contact written down | ☐ |
| Variation process and margin in writing | ☐ |
| Two or more references called | ☐ |
| Cooling-off period noted (5 business days in most states) | ☐ |
Common questions
What is the most important question to ask a builder?
Ask for the licence number, then check it yourself on your state's register. It takes five minutes and confirms the builder can legally do the work, which is the gateway to home warranty insurance and the regulator's dispute services.
How many builder quotes should I get?
Three is a common rule of thumb. Fewer gives you nothing to compare; more takes a lot of time for detailed jobs. Make sure every builder quotes on the same plans and inclusions, or the comparison is meaningless.
Should I choose the cheapest builder quote?
Not on price alone. Compare the exclusions, provisional sums and prime cost allowances first. A quote with low allowances and a long exclusions list can end up costing more once the job is finished.
Can I back out after signing a building contract?
Usually, within the cooling-off period. It is 5 business days in Queensland, Victoria and Tasmania, and 5 clear business days in NSW (contracts over $20,000) and SA. The builder may keep a small amount, such as $100 plus certain out-of-pocket costs in Queensland and Victoria.
Should I get a lawyer to review a building contract?
For a new home or large renovation, yes. A building lawyer's review costs little next to the contract price. In Victoria, getting legal advice before signing also removes your cooling-off right, so ask for the review before you sign, not after.
Sources
- QBCC: Find a licensed contractor
- QBCC: Deposits and progress payments
- QBCC: Contract variations
- QBCC: Cooling-off period
- NSW Government: Contracts for residential building work
- NSW Government: Insurance requirements for contractors working on your home
- NSW Government: Resolving building disputes
- Consumer Affairs Victoria: Building contracts
- Consumer Affairs Victoria: Changing a domestic building contract price
- Consumer Affairs Victoria: Cooling off on a building contract
- Consumer Affairs Victoria: Building plans and permits
- WA Government: Home indemnity insurance fact sheet (PDF)
- WA Government: Notice for the homeowner (PDF)
- CBS: Form 1 Your building contract, your rights and obligations (PDF)
- ACT Planning: Building contracts
- Residential Building Consumer Guide, July 2024 (Tas, PDF)
- NT Government: Residential building insurance
- Building Regulations 1993 (NT)