Building Act warranties you cannot contract out of

Since 1 January 2015, every contract for building work on a household unit in New Zealand has carried six warranties whether the contract mentions them or not, and whether the contract tries to exclude them or not. On top of that sits a twelve-month period during which the client can simply require you to come back — with the burden of proof running against you.

None of this is negotiable, and none of it depends on the size of the job — unlike the disclosure and written-contract duties that only start at the $30,000 line, these warranties attach to every household unit contract regardless of price.

Section 362I: the six warranties

"In every contract to which this section applies, the following warranties about building work to be carried out under the contract are implied and are taken to form part of the contract: (a) that the building work will be carried out — (i) in a proper and competent manner; and (ii) in accordance with the plans and specifications set out in the contract or, in the case of a non-consented small stand-alone dwelling, in accordance with the final design plans; and (iii) in accordance with the relevant building consent (if any): (b) that all building products to be supplied for use in the building work — (i) will be suitable for the purpose for which they will be used; and (ii) unless otherwise stated in the contract, will be new: (c) that the building work will be carried out in accordance with, and will comply with, all laws and legal requirements, including, without limitation, this Act and the regulations: (d) that the building work will — (i) be carried out with reasonable care and skill; and (ii) be completed by the date (or within the period) specified in the contract or, if no date or period is specified, within a reasonable time: (e) that the household unit, if it is to be occupied on completion of building work, will be suitable for occupation on completion of that building work: (f) if the contract states the particular purpose for which the building work is required, or the result that the owner wishes the building work to achieve, so as to show that the owner relies on the skill and judgement of the other party to the contract, that the building work and any building products used … will — (i) be reasonably fit for that purpose; or (ii) be of such a nature and quality that they might reasonably be expected to achieve that result."

And then subsection (2), the one that removes the usual escape:

"Subsection (1) has effect despite any provision to the contrary in any contract or agreement, and despite any provision of any other enactment or rule of law."

Warranty (a)(i) — carried out in a proper and competent manner — sits next to a separate duty on the same work. Where the job is restricted building work, s 84 already requires it to be carried out or supervised by a licensed building practitioner. The two are not the same thing: licensing controls who may do the work, the warranty is a promise about how it was done, and meeting one does not excuse you from the other.

Three of the six deserve a second look

(b)(ii) — products will be new "unless otherwise stated in the contract". This is the only one of the six with a contractual override built into it, and it is the one most likely to be relied on unwittingly. Reusing existing joinery, cladding, tiles or fixtures in a renovation is perfectly normal; doing it without the contract saying so puts you in breach of a warranty you did not know you had given.

(d)(ii) — completion by the specified date, or within a reasonable time. A contract with no completion date does not escape the warranty; it imports "a reasonable time" instead. Naming a date, with a mechanism for extending it, is usually better for the contractor than leaving it out.

(f) — the stated purpose. This one only engages where the contract states a particular purpose or result "so as to show that the owner relies on the skill and judgement" of the contractor. That makes what goes into the contract a live decision. A client's stated ambition, written into the scope, becomes a warranty about the result rather than about the work.

Note that s 362I(1)(a)(ii) was amended on 15 January 2026 by the Building and Construction (Small Stand-alone Dwellings) Amendment Act 2025, adding the reference to non-consented small stand-alone dwellings and final design plans. If your work involves one, read the current provision.

Section 362J: the person suing may never have been your client

"(1) An owner of the building or land in respect of which building work was carried out under a contract to which this section applies may take proceedings for a breach of any of the warranties set out in section 362I whether or not that person was a party to the contract."

And subsection (2) defines proceedings widely:

"(a) adjudication under the Construction Contracts Act 2002; and (b) a claim under the Weathertight Homes Resolution Services Act 2006; and (c) arbitration under the Arbitration Act 1996."

For a builder this has one consequence above all others: the person who buys the house from your client can sue you on the warranties. There is no privity defence, and adjudication — which is fast and does not require a court — is an available route.

Section 362K: the warranties travel with the building

"A provision of an agreement or instrument that purports to restrict or remove the right of a person to take proceedings for a breach of any of the warranties set out in section 362I is of no effect in so far as the provision relates to a breach other than a breach that was known, or ought reasonably to have been known, by the person to exist at the time the agreement or instrument was executed."

Read the exception carefully, because it is the only useful part for a contractor. A settlement or release covering known defects — ones the person knew about, or reasonably should have — does hold. A blanket "no further claims" clause covering everything, known and unknown, does not.

That is a practical drafting point at the end of a disputed job: identify the defects, describe them, and settle those. A generic release is worth less than it looks.

Section 362Q: twelve months, and the presumption

The warranties are one mechanism. Section 362Q is a separate, faster one.

"(1) This section applies if — (a) building work is carried out in relation to a household unit; and (b) the building work is defective; and (c) the defect is able to be remedied; and (d) the building work is carried out by or on behalf of a building contractor or the household unit is purchased from an on-seller … (2) In any case to which this section applies, the client may give notice, within 12 months from completion of the building work, to either the building contractor or the on-seller (if there is one) requiring that person to remedy the defect. (3) … the building contractor or the on-seller … must remedy the defect (including repairing or replacing defective building products used in the building work) within a reasonable time of notification in writing of the defect."

Then subsection (4), which is the provision that decides most of these disputes:

"In any case in which it is asserted against a building contractor or an on-seller that this section applies, the matters referred to in subsection (1) are presumed unless the contrary is proven."

All four limbs of subsection (1) are presumed against you. That the work was defective, that the defect is remediable, and that you carried it out — the client does not have to establish any of it in the first instance. You have to disprove it.

Section 362Q(5) adds damages on top of the repair obligation, "for any loss or damage to the client resulting from the defect (other than loss or damage through reduction in value of the product of the building work) that was reasonably foreseeable as liable to result from the defect."

And s 362Q(6) makes clear this is additional: "Nothing in this section affects the warranties set out in section 362I or limits the time for enforcing any of those warranties."

So the twelve months is not a limitation period on the warranties. It is a separate, faster remedy that expires after twelve months, sitting on top of warranty rights that outlast it.

What actually protects a contractor here

Since you cannot contract out, the protection is evidential. Section 362Q(4) reverses the burden; the only way to discharge it is with a record made at the time.

Photograph what gets covered. Framing before lining, waterproofing before tiling, services before backfilling, fixings before cladding. Dated, and stored on the project rather than on a phone.

Keep the product documentation. Warranty (b) is about suitability and newness of building products. The technical literature and the delivery dockets answer both, and neither survives in memory.

Say so in the contract when products are not new. The override in (b)(ii) only works if it is written down.

Name a completion date, and record every variation and delay. Warranty (d)(ii) is a promise about time.

Write the scope in terms of the work, not the client's ambition — unless you intend to warrant the result. Warranty (f) turns a stated purpose into a promise.

When you settle, describe the defects. Section 362K only preserves releases for known breaches.

All of that is one habit: the job file has to be built during the job. Reconstructing it afterwards is possible, expensive, and least available exactly when it is most needed — which is when someone who was never your client rings up about a house you finished three years ago.

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Checked on 29 August 2026 against the Building Act 2004 on the New Zealand Legislation website. Sections 362I to 362K and 362Q were inserted on 1 January 2015 by s 56 of the Building Amendment Act 2013 and have been amended since; s 362Q(7) excludes building work carried out before the section came into force or under a contract entered into before then. This describes the legislation and is not legal advice.

What Zirko does: it keeps documents and photos on the project, records time per person per day, and holds quotes and invoices against the same project — which is the record a s 362Q(4) presumption has to be met with. What Zirko does not do: it does not assess whether work is defective, and it is not a substitute for a contract that says what was agreed.