Building Consent Exemptions in NZ: What Can You Build Without Consent in 2026?
"Do I actually need a building consent for this?"
It's one of the most common questions we're asked at CA Architecture and in 2026, the answer has changed in a big way. As of 15 January 2026, New Zealand's biggest-ever expansion of consent-free building came into force: standalone dwellings up to 70 square metres can now be built without a building consent, provided strict conditions are met.
But the granny flat exemption is just the headline. The Building Act's Schedule 1 has long allowed a surprising amount of work without consent and it has also caught out a lot of property owners who misunderstood the fine print. (If that's already happened to you, see our guide to for fixing unconsented work here - What is a Certificate of Acceptance - and When Do You Need One?)
Here's where the rules stand in 2026, and the traps we see most often in Christchurch.
First, the golden rule: exempt doesn't mean unregulated
Every exemption in this article comes with the same two conditions that owners most often miss:
The Building Code still applies
Exempt work must still comply with the New Zealand Building Code — structure, weathertightness, durability, the lot. The exemption removes the council checking process, not the standard itself. If exempt work fails the Code, the council can issue a notice to fix, and you'll face the same insurance, lending and resale problems as any unconsented work.
Planning rules still apply
A building consent exemption says nothing about the resource consent side. There are district plan rules on setbacks, site coverage, recession planes and overlays still apply and in Christchurch, flood management areas and the Port Hills slope hazards add another layer. Plenty of perfectly "exempt" sleepouts have ended up needing resource consent because of where they were placed on the site.
With that established, here's what you can build.
The big one: the new 70m² granny flat exemption (live since 15 January 2026)
Under the new small standalone dwelling exemption, you can now build a self-contained minor dwelling of up to 70 square metres without a building consent. For Canterbury and Auckland families thinking about multi-generational living, a rental unit, or housing whānau on the family section, this is genuinely significant — but the conditions are strict and all of them must be met:
- Single storey, maximum 70m², with a simple, lightweight design — light timber or steel framing, with limits on roof and wall cladding weight. No mezzanines or lofts.
- Fully Building Code compliant - the standard hasn't dropped, only the consent paperwork.
- Designed and built (or supervised) by Licensed Building Practitioners. This is restricted building work - there is no DIY pathway. Plumbing, drainage and electrical work must be done by registered tradespeople.
- Sited at least 2 metres from boundaries and from any other building, with a maximum height of 4 metres and floor level no more than 1 metre above ground.
- Council notification at both ends: you must obtain a Project Information Memorandum (PIM) from the council before work starts, and on completion provide final plans, Records of Work, and compliance certificates.
- Simple servicing - connection to existing services where available or compliant on-site systems, with no complex setups like sewer pumps.
Two practical notes from the design side. First, the detail limits matter more than people expect - for example, a tiled level-entry shower requiring a waterproof membrane is excluded, so wet-area design needs to work within the rules from day one. Second, development contributions can still be charged through the PIM process, so "no consent" does not mean "no council fees." Budget accordingly.
The exemption is not retrospective - it only applies to builds started under the new law. And the government has signalled further expansion later in 2026, including provisions for off-site manufactured builds.
Where design input pays for itself
The exemption only works if the design genuinely fits every condition. A design that creeps to 72m², needs a membrane shower, or sits 1.8m from the boundary drops you back into full consent territory — usually discovered after money has been spent. Getting the design right against the exemption criteria first is the cheap part.
The established Schedule 1 exemptions still doing the heavy lifting
Beyond the new granny flat rules, Schedule 1 of the Building Act 2004 contains dozens of exemptions. These are the ones Christchurch property owners use most:
Sleepouts and outbuildings up to 30m² - single-storey detached buildings up to 30m² can be built without consent - without kitchen or bathroom facilities provided either a Licensed Building Practitioner carries out or supervises the work, or the design uses a lightweight kit-set/prefab approach designed to an applicable standard. (This is the pre-2026 pathway and remains useful for studios, home offices and basic sleepouts that don't need to be self-contained.)
Carports up to 40m² built or supervised by an LBP.
Decks, platforms and bridges no more than 1.5 metres above ground.
Fences and walls up to 2.5 metres (note: swimming pool fencing has its own rules and is never exempt from compliance).
Retaining walls up to 1.5 metres that don't support a surcharge a significant caveat on Christchurch's hill sites, where most retaining is doing exactly that.
Repairs and maintenance using comparable materials in the same position replacing weatherboards, re-roofing like-for-like, replacing windows in the same opening.
Internal alterations such as wall linings, cabinetry and joinery but not the removal or modification of structural walls, and not work affecting fire separations or weathertightness.
Small garden structures pergolas, arbours, and similarly minor work.
This list isn't exhaustive, and nearly every item carries conditions in the legislation. The pattern to notice: the exemptions are generous about simple, low-risk work and unforgiving about anything structural, weathertight-critical, or sanitary.
The discretionary exemption most people don't know about
There's one more pathway worth knowing: councils have the discretion under Schedule 1 to exempt any building work from consent if they're satisfied the work is likely to comply with the Building Code and any risk is low. In practice, this is used for well-documented, professionally designed work that falls just outside the standard exemptions. A strong application with proper drawings and a clear compliance case is essential, and this is something we prepare for clients where the pathway makes sense. The decision sits entirely with the council, but a good application materially shifts the odds.
The five traps we see most often
1. The kitchen/bathroom line a 30m² sleepout is exempt; add a toilet and kitchenette without consent and it isn't (unless it qualifies under the new 70m² dwelling exemption, with all of those conditions). Many "sleepouts with a bit extra" end up as unconsented dwellings.
2. Exempt building, non-exempt siting. The structure qualifies, but it's inside a setback, breaches site coverage, or sits in a flood management area. Building exemption ≠ planning permission.
3. Structural surprises during renovations. "We're only updating the kitchen" becomes "we removed a load-bearing wall." Internal alteration exemptions stop at structure.
4. Retaining walls with surcharge. That 1.4m wall holding up the driveway isn't exempt the driveway is a surcharge.
5. No paper trail. Even for genuinely exempt work, keep records: drawings, photos, LBP details, invoices. When you sell, your lawyer, the buyer's lender and the insurer will all be happier for it. We routinely prepare exemption documentation packs for exactly this reason.
Not sure which side of the line your project falls on?
This is genuinely worth a short conversation before you start — the cost of getting it wrong runs from a stalled house sale to a notice to fix, and the fix-it pathway (a Certificate of Acceptance) costs more than doing it right the first time.
CA Architecture works across these pathways every week: designing 70m² minor dwellings to fit the new exemption, preparing discretionary exemption applications, documenting exempt work properly, and advising honestly when a full building consent is actually the smarter route.
Frequently asked questions
Can I really build a 70m² granny flat without any consent in NZ?
Yes — since 15 January 2026, provided every condition is met: single storey, simple lightweight design, full Building Code compliance, LBP design and construction, 2m setbacks, a PIM before starting, and completion documentation to the council. Miss any condition and you need a building consent.
Does the granny flat exemption apply in Christchurch?
Yes, it's a national exemption. But Christchurch District Plan rules still apply to siting, coverage and hazards and development contributions may be charged through the PIM. Check the planning layer before committing to a design.
Can I build the granny flat myself?
No. The design and construction of restricted building work must be carried out or supervised by Licensed Building Practitioners, with registered tradespeople for plumbing, drainage and electrical work.
What's the difference between the 30m² and 70m² exemptions?
The 30m² pathway is for simple outbuildings without kitchen or bathroom facilities. The 70m² pathway allows a fully self-contained dwelling but carries much stricter conditions such as LBP involvement throughout, PIM, notification, siting and design limits.
What happens if I build something that needed consent?
The council can issue a notice to fix, and the work will cause problems when you sell, insure or borrow against the property. The remedy is usually a certificate of acceptance read our full guide here.
Do exemptions apply to older buildings and heritage properties?
Extra care is needed as heritage listings and character overlays in the District Plan can impose requirements regardless of the Building Act exemption. Always check both layers.
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Thinking about a minor dwelling, sleepout or renovation?
Whether it's a 70m² whānau flat under the new exemption, a home studio, or a renovation that might be simpler than you think, the right pathway decision at the start is the cheapest design decision you'll make. Get in touch with Casey and Tk to talk it through. Contact us by filling out the enquiry form on our home page https://caarch.co.nz
Already have a floor plan or an idea sketched out? Our Floor Plan Reviewis a low-commitment way to pressure-test it including whether it fits an exemption pathway before you commit to full design.
About us - CA Architecture is a Christchurch architectural design studio affiliated with Architectural Designers New Zealand (ADNZ). We design residential, commercial and community spaces across Canterbury, Auckland and New Zealand, with regular services in the minor dwelling / granny flat, Marae design, community housing and high-performance homes sectors.