When do I need a written building contract in NZ?
Short answer
In NZ, residential building work costing $30,000 or more (including GST) must have a written contract by law. The builder must also give you a disclosure statement and a checklist before you sign. Below $30,000 a written contract isn't compulsory but is still strongly recommended.
Key facts
- $30,000+ (incl GST) residential work: written contract is mandatory
- Builder must provide a disclosure statement and checklist before signing
- The contract should cover scope, price, payment schedule, variations and timeline
- Even under $30,000, get it in writing
The $30,000 rule
For residential building work of $30,000 or more including GST, a written contract is required under NZ law. The builder must also give you a disclosure statement (about their business, skills and insurances) and a checklist before you sign.
What the contract should cover
A good building contract clearly sets out:
- The scope of work and what's excluded
- The price and whether it's fixed or charge-up
- A payment schedule tied to stages
- How variations (changes) are priced and approved
- The expected timeline and what happens if it slips
Why it matters
A written contract is your main protection if something goes wrong. If a builder won't put the job in writing for work of this size, treat that as a warning sign in itself.
Knowing the rules is half the job. The other half is knowing who you're hiring — check any NZ builder's court action, insolvency history, director track record and AI risk score in 30 seconds.
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Related questions
Sources: MBIE / Building Performance — residential building contracts; Building Act 2004. General information for NZ homeowners, not legal advice — building rules change and vary by council, so confirm critical details on the official source before acting. Last updated 2026-05.