NZS 3902:2004 — the mandatory residential building contract

NZS 3902:2004 is the plain-English template contract for residential building work, and under the Building Amendment Act 2013 it’s effectively mandatory once a job hits $30,000. If you start work of that size without a written contract, the client has grounds to refuse payment or take action under the Act — so this is one bit of paperwork worth getting right before the first swing of the hammer.

When a written contract is mandatory

Under the Building Amendment Act 2013, all residential building work valued at $30,000 or more (including GST) requires a written contract before work starts. Failing to provide one gives the client grounds to refuse payment or take action under the Act.

• $30,000 or more (incl. GST): a written contract is required before work starts.
• Under $30,000: it’s still recommended to always have a written contract.
• You can use the NZS 3902:2004 template (a free download from Standards NZ), or a Master Builders or Certified Builders contract.

What the NZS 3902 template covers

The template is a design-and-build contract that bundles the terms a residential job needs into one document:

• Parties (Owner and Builder) and the site address.
• Building work description, plus the specifications and drawings list.
• Contract price and payment schedule.
• Start and completion dates.
• Defect liability period (12 months minimum).
• Variations process, insurance requirements and dispute resolution.
• Health & safety obligations and tax invoicing.
• Maintenance schedule (s362T) and the Prescribed Disclosure (Form 5).

When not to use NZS 3902

NZS 3902 is built for residential design-and-build work. Reach for a different form when:

• An architect or engineer is administering the contract — use NZS 3910:2023 instead.
• The job is labour-only — NZS 3902 is a design-and-build contract.
• The work involves buying land from the builder — you’ll need a separate sale agreement attached.
• The work is commercial or industrial — that typically uses NZS 3910 or NZIA forms.

Where to get it

The NZS 3902:2004 template is a free download from Standards NZ (it’s a sponsored standard). Master Builders and Certified Builders also offer contract forms you can use for the same purpose.