A builder’s quote is usually the biggest number you’ll see during a renovation, and it’s tempting to compare quotes by the total alone. That’s how people end up with the cheapest quote, then a string of extra charges for things the other builders had included.
This guide explains what a Victorian builder’s quote should include, how to compare quotes fairly, the parts that can change after you sign, and the legal rules on contracts, deposits and stage payments. It’s based on Consumer Affairs Victoria and Building and Plumbing Commission guidance, checked in October 2026. Other states have different rules. This is general information, not legal advice. For large or unusual projects, have a lawyer or building consultant review the contract before you sign.
First, make sure the builder is registered. Our guide to checking a tradie’s licence has the official register links.
Get three quotes on the same plans
Consumer Affairs Victoria recommends getting at least three written quotes, and making sure each builder is quoting on the same plans and specifications. If one builder quotes on a different spec, you’re comparing different jobs.
Give every builder the same documents: plans, the engineering if you have it, a finishes schedule and a list of what you want included. Ask them to quote line by line.
What a good quote includes
| Section | What to look for |
|---|---|
| Builder details | Full name, ABN, and registration number (the contract must show it) |
| Scope of work | A detailed description of what’s being built, removed and made good |
| Inclusions | Itemised list of materials, fixtures and finishes, with brands or specs where possible |
| Exclusions | What’s not included, such as landscaping, painting, permits or rubbish removal |
| Prime cost sums | Allowances for items you’ll choose later, with dollar amounts |
| Provisional sums | Estimates for work that can’t be priced exactly yet |
| Permits and fees | Who pays for building permits, surveyors and engineering |
| Timeframe | Start date and estimated duration |
| Payment terms | Deposit and stage payments |
| Validity | How long the price is held |
| GST | Whether prices include GST |
The more detail, the easier it is to compare, and the fewer arguments later.
Prime cost and provisional sums: where prices move
Consumer Affairs Victoria says the price in a domestic building contract can only change in limited ways, including:
- variations to the work, which should be agreed in writing
- prime cost (PC) sums, which are allowances for items not yet chosen, such as tapware, tiles or appliances
- provisional sums, which are estimates for work that can’t be priced exactly, such as excavation
Consumer Affairs Victoria suggests avoiding these items where you can, by putting the exact make, model and price of your selections in the contract. Your builder must give you invoices showing the actual cost of PC and provisional items. A low quote with small PC allowances can look cheaper but cost more once you choose real fixtures. Compare the allowances across quotes, and check they’re realistic for the finishes you actually want.
Contracts: the rules in Victoria
- Over $10,000: domestic building work needs a major domestic building contract. Consumer Affairs Victoria says this applies even if the work is split into several smaller contracts.
- Consumer guide: the builder must give you the Domestic Building Consumer Guide before you sign.
- Registration number: the builder’s registration number must be on the contract.
- Cooling-off: you have five business days after receiving a signed copy of the contract to withdraw, and conditions apply.
Deposits and stage payments
Deposits. In Victoria, the maximum deposit is 10% for contracts under $20,000 and 5% for contracts of $20,000 or more.
Insurance before deposit. Where domestic building insurance or Home Warranty is required, the builder must give you evidence of cover before you pay the deposit. For contracts from 1 July 2026, Home Warranty applies above $20,000. Our tradie check guide explains the thresholds.
Stage payments. For contracts covering all the usual stages of a new home, Consumer Affairs Victoria sets maximum progress payments as a percentage of the contract price:
| Stage | Maximum payment |
|---|---|
| Base | 10% |
| Frame | 15% |
| Lock-up | 35% |
| Fixing | 25% |
Only pay for a stage once it’s actually complete and has passed the building surveyor’s inspection. Renovations and other contracts may have different payment schedules, so check the contract and Consumer Affairs Victoria’s guidance.
Checking the builder behind the quote
A detailed quote is only as good as the builder who wrote it. Before you compare prices, check each builder’s registration on the Building and Plumbing Commission register, and make sure the name and number on the quote match. Ask for recent references from jobs like yours, and if you can, look at finished work. Ask who will actually run your job day to day, and whether parts of it will be subcontracted. A builder who answers these questions clearly and in writing is usually easier to deal with when something changes during the build.
Red flags in a quote
- A lump sum with no breakdown. You can’t compare it or check what’s missing.
- A deposit above the legal limit, or a request for cash up front.
- No registration number, or a business name that doesn’t match the register.
- Big gaps in exclusions, such as permits, site clean-up or connections.
- Pressure to sign quickly, or a “today only” price.
- Much lower than the others. Find out why before you get excited.
- Vague timeframes with no start date.
Comparing quotes side by side
Make a simple table with one row per item, such as demolition, framing, electrical, plumbing, waterproofing, tiling, fixtures and clean-up, and one column per builder. Fill in what each includes and its price. Gaps show you what to ask about. Then add up the PC and provisional sums separately so you can see how much of each quote is still an estimate.
Trade quotes from plumbers and electricians work the same way. Our Melbourne plumber and electrician cost guides cover typical pricing and what certificates you should get.
Smaller jobs under $10,000
The major domestic building contract rules apply to work over $10,000, but smaller jobs still deserve a written quote. Ask for the scope, inclusions, exclusions, price including GST and payment terms in writing, and keep emails and messages. If the work is plumbing or electrical, ask what compliance certificate you’ll receive at the end.
After you sign
- Keep everything. Store the contract, plans, specifications, the consumer guide and all variations together.
- Variations in writing. Before any change goes ahead, get the price and the effect on the timeframe in writing, and sign it.
- Check each stage. Before paying a progress claim, check the stage is finished. Some homeowners hire an independent building inspector at key stages.
- Keep a diary. Short notes and photos of progress and conversations help if there’s a dispute.
If something goes wrong, raise it with the builder in writing first. If that doesn’t fix it, Domestic Building Dispute Resolution Victoria offers a free service for many domestic building disputes.
Questions to ask before you sign
- What exactly is excluded?
- How were the PC and provisional sums worked out?
- How are variations priced and approved?
- When will you start, and how long will it take?
- Is the builder’s insurance in place, and can I see it?
- What happens if the job runs late?
- Who’s my contact on site?
If an answer isn’t clear, ask for it in writing.
Common questions
What is a prime cost sum?
A prime cost (PC) sum is an allowance in the contract for an item that hasn't been chosen yet, such as tapware, appliances or tiles. If what you choose costs more or less than the allowance, the price changes. Consumer Affairs Victoria says a contract can only change price in limited ways, including through PC and provisional sums and variations.
What is a provisional sum?
A provisional sum is an estimate for work the builder can't price exactly yet, such as excavation. The final cost can go up or down, so ask how the allowance was worked out and what it includes.
How much deposit can a builder ask for in Victoria?
Under Victorian rules, the maximum deposit is 10% for contracts under $20,000 and 5% for contracts of $20,000 or more. On jobs where domestic building insurance or Home Warranty is required, the builder must give you evidence of cover before you pay the deposit.
Is a quote the same as a contract?
No. A quote is the builder's offer. For domestic building work over $10,000 in Victoria, you need a major domestic building contract, and the builder must give you a copy of the Domestic Building Consumer Guide before you sign.
