All advice / Planning and cost
Why the contract matters
A bathroom renovation is a significant purchase — $18,000 to $30,000 or more. The contract is the document that protects both you and the builder. It sets out what will be done, what it costs, how changes are handled and what happens if something goes wrong.
In NSW, a written contract is legally required for residential building work over $5,000. For work over $20,000, the Home Building Act requires specific clauses including a cooling-off period, progress payment schedule and details of the builder's insurance.
Scope of work
The contract should list every item included in the renovation: strip-out, waterproofing, plumbing, electrical, tiling, fixtures, painting, clean-up and waste removal. Each item should be described clearly enough that there is no ambiguity about what is included and what is not.
If the quote says "bathroom renovation" without listing the inclusions, ask. A vague scope leads to disputes about what was and was not agreed. Our guide to comparing quotes covers what a detailed scope looks like.
Fixed price vs cost-plus
A fixed-price contract sets the total cost for the agreed scope. You know the price before work starts. If the builder finds a problem — rot, old plumbing — any additional cost is discussed and agreed in writing before the extra work goes ahead.
A cost-plus contract charges materials at cost plus a margin, and labour at an hourly or daily rate. The final cost is not known until the job is finished. This suits large, complex projects where the full scope cannot be defined in advance, but it carries more financial risk for the homeowner.
ETR uses a HIA fixed-price renovation contract. The price is tied to the agreed scope and does not change unless a variation is approved in writing.
Payment schedule
The contract sets out when payments are due. A standard schedule for a bathroom renovation is a deposit (typically 10 to 30 percent), one or two progress payments tied to milestones (such as completion of waterproofing and completion of tiling), and a final payment on handover.
In NSW, the Home Building Act caps the deposit for residential work at 10 percent for contracts over $20,000. For contracts under $20,000, a reasonable deposit is agreed between the parties.
ETR's payment schedule is 30 percent deposit, 40 percent at a defined milestone and 30 percent on completion. This is set out in the contract before work starts.
Variations and extras
A variation is a change to the agreed scope — a different tile, an additional niche, a wall that needs reframing because of rot. The contract should state that variations must be agreed in writing before the extra work begins, and that the cost of the variation is documented.
Verbal agreements about extras are hard to prove. A good contract makes variations a formal process — a written description of the change, the cost impact, and both parties' signatures — so there are no surprises on the final invoice.
Warranty and insurance
The contract should state the workmanship warranty period. ETR provides a 10-year workmanship warranty. This covers the builder's work — not the products themselves, which carry the manufacturer's warranty separately.
The builder should hold public liability insurance and workers' compensation insurance. In NSW, for residential work over $20,000, the builder must also provide a Home Building Compensation Fund (HBCF) certificate, which protects the homeowner if the builder cannot complete the work.
Our insurance guide covers what insurance means for you during a renovation.
What ETR's contract covers
ETR uses a HIA fixed-price renovation contract — a standard industry document published by the Housing Industry Association. It covers scope, pricing, payment schedule, variations, warranty, insurance, dispute resolution and cooling-off period.
The contract is explained before you sign. Every job is carried out under NSW Builder Licence 475204C, with $20 million public liability insurance and a 10-year workmanship warranty. A free on-site measure anywhere in Sydney is the starting point.
Frequently asked questions
Is a written contract required for a bathroom renovation?
In NSW, yes — for residential building work over $5,000, a written contract is required by law. For work over $20,000, the Home Building Act requires specific clauses including a cooling-off period and a progress payment schedule.
What is a HIA contract?
A HIA contract is a standard-form building contract published by the Housing Industry Association. It is widely used in residential renovations across Australia. It covers scope, pricing, payments, variations, warranty, insurance and dispute resolution in a format that meets legal requirements.
Can I negotiate the payment schedule?
The schedule is usually set by the contract type and legal requirements. In NSW, the deposit is capped at 10 percent for contracts over $20,000. Progress payments are tied to milestones. The final payment is due on completion and handover.
What happens if the builder finds a problem during the renovation?
Under a fixed-price contract, the builder discusses the problem with you, describes the extra work needed, provides a cost for the variation and gets your written approval before proceeding. The variation is documented and added to the contract.
What should I do before signing a renovation contract?
Read the full document. Check that the scope lists every inclusion. Confirm the payment schedule. Verify the builder's licence number on the NSW Fair Trading register. Ask for proof of insurance. Understand how variations are handled. Ask any questions before you sign.