A new kitchen, a second bathroom and a structural wall taken out to open up the living area. Under a Bill now before Parliament, a renovation like that, once it reached $100,000, would need a home warranty in place before the building work could go ahead.

The Building Amendment Bill isn’t law. It has passed its first reading and is with Parliament’s Transport and Infrastructure Committee, which is due to report back by 29 December 2026. The details could change before it passes.

What the warranty would cover

As introduced, the Bill would require a home warranty for new houses and new small-to-medium apartment buildings, and for renovations of existing ones with an estimated value of $100,000 or more including GST. In every case the project must involve restricted building work that needs a building consent. The Bill defines a small-to-medium apartment building as a fully residential building under 10 metres tall.

The warranty would have to cover all defective building work for one year and structural defects for 10 years, with the start of each period set by regulations. It must be enforceable by you as the homeowner who commissioned the work, and transfer to the next owner if you sell during the cover period. It would come from a provider registered with the Ministry of Business, Innovation and Employment (MBIE).

Before granting a consent, your building consent authority, usually the council, would check for evidence of the warranty. Without it, the authority would issue a certificate stopping the building work, or limiting it, until the evidence arrives. Carrying out work against that certificate would be an offence, with a fine of up to $50,000 for an individual.

The Bill doesn’t set a price or say who pays. MBIE’s 2025 regulatory impact statement expects a small rise in costs for homeowners who wouldn’t otherwise have bought a warranty. It put current premiums on a typical $500,000 build at about $1,250, or 0.24% of build value, for a guarantee product, up to around $2,750, or 0.55%, for an insurance-backed warranty.

The same statement found about 46% of new residential builds are covered by a warranty, and even fewer renovations.

The warranties come with a bigger change. At present, when several parties contribute to a defect, you can recover the full cost from any one of them, and the Bill’s explanatory note says councils have carried a disproportionate share.

The Bill moves to proportionate liability, where each party pays only its own share, and the note acknowledges claimants “can no longer seek full recovery if a liable party is absent or insolvent”. The warranty is meant to cover that gap.

The home warranty rules would start on the first anniversary of Royal assent, with providers able to register from three months after assent. Until the Bill passes, there’s no start date.

What protects you now

Every residential building contract, written or spoken, already carries implied warranties under the Building Act 2004. The work must be done competently and with reasonable care and skill, follow the plans and consent, and use suitable materials that are new unless the contract says otherwise. A contract can’t sign those rights away, and a later owner can enforce them too.

If you tell your builder about a defect within 12 months of the work being completed, the Act says they must fix it. Beyond that, no claim over building work can succeed if it’s brought 10 years or more after the act or omission it’s based on.

For work of $30,000 or more including GST, your builder must give you a written, dated contract, along with prescribed disclosure information and a checklist before you sign. The disclosure form asks the builder to list their insurance policies and any guarantees or warranties they offer, with the cover period and exclusions.

Voluntary guarantees already exist. Master Builders says its Master Build 10-Year Guarantee covers materials and workmanship for two years and structural defects for 10 years, and only its members can offer it. New Zealand Certified Builders says its Halo guarantee gives two years for workmanship and materials, up to 10 years for structural defects, and transfers to future owners.

How to have your say

Anyone can make a submission to the select committee through Parliament’s website. MBIE’s announcement gave 15 November 2026 as the closing date, but Parliament’s Bill page now lists submissions as open with no fixed date, so check there before you write.

If a big renovation is on the cards, the builder’s disclosure statement is the place to start. It’ll tell you what guarantee they offer and what it leaves out.