What is the Master Build Guarantee and what does it cover?
Short answer
The Master Build 10-Year Guarantee is a paid insurance product issued through Registered Master Builders. It covers non-completion, loss of deposit (up to a cap), defects, and structural failure for ten years. It's only available if your builder is a Registered Master Builder and is taken out at contract signing. A deposit over the policy's stated limit usually voids the deposit cover, so the deposit clause is the one to watch.
Key facts
- Only Registered Master Builders can offer it — that's a paid membership, not a government licence
- Cover is split into deposit, non-completion, defects, and structural — different sub-limits for each
- Deposit cover usually caps at 10% of contract price — pay more upfront and you may lose protection
- It has to be set up at contract signing — you can't add it later
- It's underwritten by an insurer (currently Berkley Re), not the Master Builders themselves
What it covers — the four limbs
Loss of deposit: if the builder fails to start the job and goes insolvent, the policy refunds your deposit up to the limit (currently usually 10% of contract price or a hard cap, whichever is lower).
Non-completion: if the builder fails to finish, the policy contributes to the cost of completing with a new builder.
Defects period: covers defects identified within the policy's defects window (typically 2 years for general defects, 10 years for structural).
Structural: ten-year cover for major structural failure caused by the builder's work.
Why the deposit clause matters
Master Build Guarantee deposit cover has a percentage and a dollar cap. If you pay more than the cap, the policy will only refund up to the cap — even if you lost more.
Some homeowners pay a 20-30% deposit thinking they're being responsible. If the builder fails, anything above the policy cap is lost.
How to claim
Claims go through Registered Master Builders, who pass it to the underwriter. There's a strict notification window (often 14 days from awareness of the event). Missing the window is the most common reason claims fail.
Document everything from day one — keep the contract, every variation, every payment receipt, and every email.
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 minutes.
Planning the project? See the costs
Related questions
Sources: Registered Master Builders — masterbuilder.org.nz; Master Build Guarantee policy wording. 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.