The rules at a glance
Each rule depends on the value of the work — labour and materials together, including GST. They add up: a $30,000 job triggers all of them.
Any residential building work needs a written contract, signed and dated by both of you. There are two versions: $5,000–$20,000 and over $20,000. You can fill it in yourself — if you use the trade’s contract, you get their terms; if you give them yours, you get their price on your terms.
You need an owner-builder permit for work that needs development consent (or is complying development) on a house, dual occupancy or secondary dwelling. You apply through Service NSW. You must be 18 or over, own the land, and live there once the work is finished.
You must complete the approved owner-builder course before the permit is issued. And most (but not all) trades doing residential building work must give you a home warranty insurance (HBCF) certificate before taking any money, including a deposit.
You need a White Card (general construction induction). It’s a separate course, and you must have it before you apply.
The statutory warranties pass to the next owner. Whoever buys from you is covered as if you were a licensed builder who built under contract with them: 6 years for major defects, 2 years for others, from completion. If a problem appears in the last 6 months of either period, they get another 6 months to take action.
If you sell within 7 years and 6 months of the permit date, the sale contract must include a clear warning that a permit was issued and the work doesn’t have to be insured unless a contractor did it. Leave it out and the buyer can cancel the contract.
What you’re taking on
The saving is real: you keep what a builder would charge for margin and overheads. What people underestimate is what that margin paid for — not the building work itself, but running the job:
- Around twenty trades on a new home, each needing a scope, a price, a contract and a place in the schedule.
- A building order that can’t slip. Miss the waterproofer’s slot and you wait two weeks — and everything after it waits too.
- Certificates for each stage. Waterproofing, electrical, plumbing, glazing, termite protection, engineering — each collected before the work is covered up or paid for. Afterwards is too late.
- Every change in writing, priced and agreed before the work is done. This is where most owner-builders lose the money they set out to save.
- The legal responsibility. The warranties, site safety, and the warning when you sell are all yours now.
Two things nobody warns you about
Trades charge owner-builders more — and the good ones often say no
Their reason is simple: many owner-builders are disorganised. No written scope, a site that isn’t ready, decisions made halfway through, and an expectation of free advice. Waiting around costs a tradie their day rate, so they add a margin for the risk — or don’t quote at all.
But they also say an owner-builder with no experience who is simply organised gets treated like a builder. Their reasons, in their own words →
Banks lend owner-builders less
Banks commonly lend 80–95% of the finished value on a builder-run job. For owner-builders, most cap it at 60–70% — so you need a much bigger deposit — and many won’t lend at all. It varies by lender. The money is released stage by stage, only once the bank is satisfied each stage is finished. Between stages, you pay the costs yourself.
What they ask for — signed quotes from licensed trades, insurance, a month-by-month timeline — is the same paperwork trades respect. What banks ask for, and why →
What helps: paperwork, done before you start
A written scope for each trade. A building schedule. A contract ready to sign before you call anyone. Then, as the job runs, the certificates, notices and records the contracts require. It only helps if it exists before you hire a trade — that’s when they price your job and when the bank assesses you.
What paperwork can’t do: it can’t change a bank’s lending policy or make a trade quote you like a builder. What it changes is what they’re judging. A trade prices a clear scope instead of an unknown job. A bank reads a complete application. And if something goes wrong, those same documents are the record everyone relies on.
How eSiteOffice helps an owner-builder
- Get comparable quotes. Every trade quotes on the same form, the same scope of works and the same conditions, through a web page — nothing for them to install. You can compare like with like before you choose.
- Turn the chosen quote into a contract. Signed electronically and filed.
- Every change priced and agreed before it’s built. Changes in writing, or they don’t happen.
- Every deadline tracked. Any trade you hire can send you a payment claim. Miss the reply date and you owe the full amount. eSiteOffice counts the days for you.
- A file the bank can check. Contracts, changes, payments, photos and sign-offs — dated and in order.
Opens in October. Register to be one of the first to use it and keep the launch price for as long as you stay.