Nearly half of all new residential builds in New Zealand currently have no structural warranty backing. If a builder goes under or defective work appears years later, the homeowner is left carrying the full cost. That situation is about to change. The Building Amendment Bill, expected to pass through Parliament in 2026, will make a 10-year structural warranty mandatory on every new home and on major renovations over $100,000. For anyone building or buying a home in New Zealand, the shift from an opt-in system to a compulsory one changes what you need to check, what you can expect to pay, and who bears the risk if something goes wrong.
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This article is general information only and does not constitute professional advice. For your specific situation, consult a qualified professional.
Right now, you get a 10-year structural warranty only if your builder belongs to Master Builders or New Zealand Certified Builders, or if your contract specifically includes cover from a provider like Stamford or Builtin. That leaves a lot of homes exposed. The new rules will flip that: every new residential build up to three storeys, and any renovation costing $100,000 or more that involves restricted building work and a building consent, will come with a mandatory warranty. The premium, typically 1–2% of the contract price, gets folded into the build cost. The builder must register with an approved warranty scheme, and the warranty provider must be registered with MBIE and able to demonstrate it can meet claims over the full 10-year period. If you’re planning a build or a major renovation, understanding how property insurance and warranties interact is becoming more important than ever. Here’s what you actually need to know.
A home warranty is a policy that covers the cost of fixing structural defects in a new home for a set period. Unlike standard building insurance, which covers things like fire or storm damage, a warranty specifically covers defects in the design, materials, or workmanship that appear after completion. The new mandatory system will require a minimum 1-year defect period for non-structural issues and a full 10-year structural warranty.
What I tend to notice is that most people focus on the build cost and the design, and barely glance at the warranty paperwork. That’s the part that matters if something goes wrong years later.
What the New Mandatory Warranty Actually Covers
The Building Amendment Bill introduces a mandatory home warranty for all new residential buildings up to three storeys and for renovations of $100,000 or more that involve restricted building work and a building consent. The warranty must include a 1-year period for non-structural defects and a 10-year structural warranty. The builder is the primary obligor, meaning they are responsible for remedying defects, and the warranty provider steps in if the builder cannot or will not act.
The table below lays out how the current opt-in system compares with the proposed mandatory system, so you can see exactly what changes and what stays the same.
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| Feature | Current System | Mandatory System (proposed) |
|---|---|---|
| Coverage trigger | Opt-in — only if builder is in Master Builders, NZCB, or has independent cover | Mandatory for all new residential builds up to 3 storeys and renovations ≥ $100,000 |
| Structural warranty term | 10 years, but only if covered | 10 years, mandatory |
| Defect period (non-structural) | Varies by scheme | Minimum 1 year |
| Liability model | Joint-and-several | Proportionate (fault-based) |
| Builder registration required | No | Yes — must register with an approved warranty scheme |
| Typical cost | $1,200–$2,750 (one-off) | 1–2% of contract price, included in build cost |
| Warranty provider oversight | Minimal | MBIE registration and actuarial requirements |
The cost of the warranty, typically 1–2% of the contract price, will be included in the contract price. On a $500,000 build, that’s around $5,000 to $10,000 — a noticeable sum, but one that buys a decade of structural protection. The new system also requires warranty providers to register with MBIE and demonstrate they can meet claims over the full 10-year period, verified by independent audit. That’s a significant upgrade from the current system, where some providers have minimal oversight.
Where People Get Tripped Up
The research points to several recurring gaps in how people approach building damage coverage. Here are the most common ones, and what they mean in practice.
Assuming the builder’s membership covers you
Just because a builder belongs to Master Builders or NZCB doesn’t automatically mean your specific project is covered. The warranty is usually tied to the contract, not the membership. You need to see the certificate or policy document. If the builder can’t produce one, you’re not covered. The mandatory system will fix this by requiring registration with an approved scheme, but until then, ask for the warranty certificate before signing anything.
Confusing building insurance with a structural warranty
Building insurance covers events like fire, storm, or vandalism. A structural warranty covers defects in design, materials, or workmanship. They are not the same thing, and one does not replace the other. If your builder disappears and your roof leaks because of poor workmanship, your building insurance will likely not pay out. The warranty is what covers that. Knowing what your property insurance actually covers is essential, but it won’t fill the gap left by a missing warranty.
Relying on joint-and-several liability to protect you
Under the current system, if a builder goes under, the council or another solvent party can be held liable for the full cost of repairs. Many homeowners assume that means they’ll always be made whole. The shift to proportionate liability changes that. Under the new rules, each party pays only for their share of the fault. If the builder is insolvent and has no assets, and the council is only 20% at fault, you could be left with 80% of the repair bill. Duncan Cotterill’s analysis notes that this introduces new risks for homeowners if a liable party becomes insolvent. The warranty is the actual protection — don’t rely on the liability laws to save you.
Waiting for the law to change before checking your position
The bill is expected to pass in 2026, with most changes operative late 2026 or 2027. If you’re building or renovating now, you’re still in the current system. The mandatory warranty won’t apply retroactively to existing contracts. If you’re planning a build in the next 12 months, you need to check the warranty position now, not later. Ask your builder which scheme they use, get the certificate, and confirm the terms. If they’re not offering any warranty, that’s a red flag.
How to Secure Real Protection Before the Law Changes
Until the mandatory system takes effect, the responsibility for checking warranty coverage sits with you. Here’s what to do, in order.
Check your builder’s warranty status
Start by asking your builder directly whether they offer a 10-year structural warranty and which scheme they use. Master Builders and New Zealand Certified Builders both have their own warranty schemes. Some builders use independent providers like Stamford or Builtin. If the builder is not a member of either association and doesn’t offer independent cover, you have no warranty backing. You can use a service like CheckMyBuilder to pull together NZBN data, LBP records, court records, and director history into one report. That gives you a clearer picture of who you’re dealing with.
Get the warranty certificate in writing
A verbal assurance that the builder is “covered” is not enough. Ask for the warranty certificate or policy document before you sign the contract. It should state the term (1-year defect period and 10-year structural cover), what is and isn’t covered, and the process for making a claim. If the builder can’t or won’t provide it, that’s a clear sign to proceed with caution. If you need help reviewing the contract terms, a real estate law professional can walk you through the fine print.
Understand the cost and how it’s paid
The typical cost for a 10-year warranty today is between $1,200 and $2,750, paid as a one-off premium. Under the new mandatory system, the cost will be 1–2% of the contract price and included in the build cost. If a builder quotes a very low price and doesn’t mention a warranty, ask where the warranty cost is included. If it’s not, you’re either not covered or the builder is cutting a corner.
Know what to do if a defect appears
Under the current and proposed systems, the process is similar. If you notice a defect within the warranty period, you must notify the builder in writing. The builder has a reasonable opportunity to investigate and remediate. If they don’t, you escalate to the warranty provider, who may conduct an independent assessment. If the claim is valid, the warranty provider pays for or arranges the remediation. Keep all correspondence and take dated photos. The timeline matters — if you miss the notification window, you lose cover.
Prepare for the new rules even if you’re not building yet
The bill is still going through Parliament, and the final regulations for warranty schemes, professional indemnity insurance levels, and self-certification criteria have not yet been published. But the direction is clear: mandatory warranties, proportionate liability, and tighter professional indemnity requirements. If you’re in the design, engineering, or building surveying professions, expect to need professional indemnity insurance as a legal requirement. More than 90% of designers and engineers already hold it voluntarily, but the new rules will make it compulsory for certain professions. Builders should start looking at which approved warranty scheme they will register with. If you’re a homeowner planning a build in the next two years, factor the warranty cost into your budget now. Navigating the full picture of property protection in New Zealand is becoming more straightforward, but it does require a bit of homework.
Does the mandatory warranty apply to existing homes? ▾
What happens if my builder goes under during the warranty period? ▾
Are renovations under $100,000 covered by the new warranty rules? ▾
Can I buy a warranty directly as a homeowner? ▾
What’s the difference between the 1-year defect period and the 10-year structural warranty? ▾
When will the mandatory warranty rules actually take effect? ▾
Don’t Assume the New Rules Will Catch Everything
The shift to mandatory warranties and proportionate liability is a genuine improvement for New Zealand’s building sector. But it’s not a silver bullet. The warranty regulations have not yet been drafted — details like deposit cover percentages, defect window definitions, and excluded events remain unknown. The bill could change significantly through Select Committee and parliamentary vote. And the move to proportionate liability means that if a builder goes under and is mostly at fault, you as the homeowner could be left with a significant share of the cost. The warranty is the protection that matters. Check it, get it in writing, and understand what it covers before you sign. The law is heading in the right direction, but it’s not there yet, and it won’t protect you retroactively.
Remember: this article is general information only. For advice on your specific situation, speak to a qualified professional.
If this was useful, you might also want to read 10 Easy Ways To Lower Your Property Insurance Premium In New Zealand.
Sources and Further Reading
Understanding Rental Lease Coverage And Property Insurance In NZ — A useful next read if you’re managing rental properties and want to see how warranty obligations interact with landlord responsibilities.
Flooding Frenzy: Understanding Your Property Insurance Before The Rain Starts In NZ — Explains how weather-related damage is treated differently from structural defects, an important distinction when reviewing your overall coverage.
CheckMyBuilder (2026). Building Amendment Bill 2026 — Guide. 🔗
Duncan Cotterill (2026). Building Reform — Key Changes Affecting Consumers and the Building Industry. 🔗
Global Law Experts (2026). Mandatory Home Warranties New Zealand 2026. 🔗
