Can a builder charge more than the quote in NZ?
Short answer
It depends whether you have a fixed-price contract or a charge-up (cost-reactive) arrangement. A genuine fixed-price quote shouldn't change unless you approve a variation or the scope changes. Estimates and charge-up jobs can move with the actual labour and materials used. Always get the pricing basis in writing before work starts.
Source: MBIE / Building Performance — residential building contracts. Updated May 2026.
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Check a builderKey facts
- Fixed price: shouldn't change without an agreed variation
- Charge-up / estimate: can move with actual costs
- Variations must be agreed — ideally in writing — before the work
- Get the pricing basis in writing before you start
Quote vs estimate vs charge-up
A 'quote' usually implies a fixed price for a defined scope. An 'estimate' is an educated guess that can change. A 'charge-up' (or cost-reactive) job is billed on actual labour and materials, so the final figure isn't locked in. These mean very different things for your budget.
Variations — the usual culprit
Most price increases on fixed-price jobs come from variations — changes to the scope, or things found once work starts (especially in older homes). A good builder prices and gets sign-off on variations before doing them, not after.
Protect yourself
Make sure your contract states whether the price is fixed or charge-up, and sets out a clear variations process. For work of $30,000 or more this should be in your written contract.
Knowing the rules is half the job. The other half is knowing who you're hiring. Check any NZ builder against the public record: company status, licensing and insolvency notices, from the official NZ sources.
Related questions
Sources: MBIE / Building Performance — residential building contracts. 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.