A written building contract is one of the most important documents you'll sign as a homeowner. In New Zealand, the law requires a written contract for most residential building work costing $30,000 or more (including GST), and having one in place — no matter the job size — protects both you and your builder if anything goes wrong.
Why a Written Contract Is Required
Under the Building Act 2004, builders carrying out residential building work valued at $30,000 or more must provide a written contract before work begins. This requirement is enforced through the Licensed Building Practitioners (LBP) scheme, and failing to provide one can result in disciplinary action against the tradesperson. Even for smaller jobs, a written agreement is strongly recommended — a handshake deal leaves you exposed if disputes arise.
Key Things a Building Contract Must Include
The following elements are either legally required or considered essential best practice for any NZ residential building contract:
1. Names and Contact Details
- Full legal names and contact details of both the homeowner (client) and the builder (contractor)
- The builder's LBP licence number (if they hold one) and their company name if applicable
2. Description of the Work
- A clear scope of work — what will be built, altered, or repaired
- Reference to the plans and specifications (these should be attached or clearly identified)
- The address of the property where work will be carried out
3. Price and Payment Terms
- The contract price (fixed price, or the basis for calculating cost if it's a cost-plus contract)
- A payment schedule — when payments are due and what triggers each payment (e.g. completion of foundations, framing, roof)
- How variations (changes to the original scope) will be priced and approved — always in writing
- GST must be clearly stated
4. Start and Completion Dates
- An estimated start date and completion date (or a method for determining them)
- Provisions for what happens if there are delays — including weather, supply issues, or client-requested changes
5. Building Consent Details
- Who is responsible for obtaining building consent from the local council
- Costs associated with consents and inspections, and who pays them
- Always confirm consent requirements with your local council — MBIE Building Performance has useful guidance on when consent is needed and what qualifies as a Schedule 1 exemption
6. Insurance Requirements
- Confirmation that the builder holds public liability insurance and, where applicable, contract works insurance
- Details of any homeowner insurance obligations during the build
7. Statutory Warranties
Under the Building Act, builders must provide certain implied warranties by law. These include that:
- Work will be carried out with reasonable care and skill
- Materials will be fit for purpose
- The completed work will comply with the New Zealand Building Code
- The work will be completed by the agreed date (or within a reasonable time)
Your contract should acknowledge these warranties and may include additional ones from the builder.
8. Dispute Resolution Process
- A clear process for raising and resolving disputes — ideally starting with direct negotiation, then mediation, before escalating to formal proceedings
- Many standard contracts reference the Weathertight Homes Resolution Service or suggest using a neutral mediator
- Consumer NZ has helpful advice on resolving contractor disputes
9. Retentions (for Larger Projects)
- If a retention (a percentage held back until defects are remedied) applies, this must be clearly stated, including the percentage and when it will be released
10. Health and Safety Obligations
- Responsibilities under the Health and Safety at Work Act 2015, including who manages site safety
- Refer to WorkSafe NZ for guidance on construction site obligations
Standard Contract Templates
Rather than drafting a contract from scratch, many NZ builders and homeowners use standard form contracts. The New Zealand Certified Builders (NZCB) and Registered Master Builders associations both offer well-regarded contract templates. These are written with NZ law in mind and cover most of the elements above. Ask your builder which template they use and read it carefully before signing.
A Handy Checklist
| Contract Element | Required by Law? | Best Practice? |
|---|---|---|
| Names and contact details | Yes | Yes |
| Scope of work and plans | Yes | Yes |
| Fixed price or cost-plus basis | Yes | Yes |
| Payment schedule | Yes | Yes |
| Variation process | No | Yes |
| Start and completion dates | Yes | Yes |
| Insurance details | No | Yes |
| Statutory warranties | Yes (implied) | Yes |
| Dispute resolution | No | Yes |
| Health and safety responsibilities | No | Yes |
When to Call a Professional
If your project involves structural work, alterations to weathertightness, or anything requiring building consent, you should be working with a Licensed Building Practitioner. For complex or high-value projects, consider having a solicitor review the contract before you sign — the cost is small compared to the risk of a poorly worded agreement. You can find qualified, experienced local builders on tradedirectory.co.nz.
Never start work without a signed contract in place, and never make progress payments without a clear record of what has been completed.
Registered Master Builder
Licensed Building Practitioner (LBP)
