Quick answer
“No consents needed” is two exemptions, not one, and a granny flat has to clear both. The Building Act exemption drops the building consent if the unit is new, single storey with no mezzanine, 70 square metres or less, under 4 metres above floor level, 2 metres clear of buildings and boundaries, lightweight-framed and LBP-supervised. The NES-DMRU drops the resource consent if it is one detached minor residential unit per site, in a residential, rural, mixed use or Māori purpose zone, 70 square metres internally, 2 metres off the principal dwelling, inside that zone’s boundary setbacks and — in residential — under 50 per cent building coverage. Pass one, fail the other, and you still need a consent.
Key points
- Both exemptions took effect 15 January 2026, but the Building Act tests how you build the unit and the NES-DMRU tests where you put it.
- In a rural zone they disagree outright: the Building Act wants 2 metres from any boundary, the NES-DMRU wants 10 from the front and 5 from the sides and rear.
- In a residential zone the NES-DMRU caps building coverage at 50 per cent, so an existing house and garage can push a compliant flat into a resource consent.
- The exemption also rules out a mezzanine, a floor over 1 metre above ground, cladding over 220kg per square metre and pumped systems inside.
- Both paths still need a PIM before you start and a notification on completion.
One granny flat has to pass two separate tests.
Two enquiries land the same week. One is a lifestyle block off Coatesville-Riverhead Highway, where the owner wants a flat out the back for her mother. The other is 405 square metres in Sandringham with a bungalow, a garage and a deck on it already. Both read the same headline — granny flats, seventy square metres, no consents. Neither needs a building consent. Both need a resource consent.
That is not a gotcha. It is what happens when two rules land on the same day and get reported as one. On 15 January 2026 the Building Act exemption for small stand-alone dwellings came into force, and so did the National Environmental Standards for Detached Minor Residential Units. One is building law, the other planning law. Confirm your own site with the council and your LBP before you order anything.
Two rules, two Acts, one build
The easiest way to hold them apart is to ask what each worries about. The Building Act exemption asks whether the thing is simple and safe enough that nobody needs to check the plans first: framing, cladding weight, height, floor level, drainage falls. The NES-DMRU asks whether it is acceptable here: zones, boundaries, coverage.
Neither is a free pass. The exemption still requires the unit to meet the Building Code in full, an LBP to carry out or supervise the work, registered plumbers and drainlayers on the wet work, a PIM before you start and a notification on completion. The NES-DMRU is not a consent at all — it says a compliant unit is a permitted activity. Fail one standard and it stops applying; your district plan takes over.
What the building consent exemption actually tests
MBIE publishes a building design conditions checklist, and it is narrower than the headline suggests. The unit must be new, single storey with no mezzanine, standalone and detached, self-contained to the Building Code requirements for housing — detached dwelling, and for a single household. Then the conditions start.
- Floor area 70 square metres or less, floor no more than 1 metre above supporting ground, height no more than 4 metres above floor level.
- Two metres or more from other residential buildings and legal boundaries, and not across an allotment boundary.
- Roof cladding to a maximum 20kg per square metre, wall cladding to 220kg per square metre, light steel or timber framing.
- Water, surface water and foul water on the network utility operator; on-site systems only where the network is unavailable.
- Fixture units not over 30, no pumped systems inside, minimum drain sizes and grades, no uncontrolled water heating.
- Independent electricity supply, and electric or gas heaters if installed.
What the NES-DMRU actually tests
The planning side is shorter, which is exactly why people misread it. A detached minor residential unit is self-contained, ancillary to the principal residential unit, completely detached, on the same site, held in common ownership with it. One per site is permitted, and only in four zone types — National Planning Standards names, so check which one your site is actually in.
- Floor area equal to or less than 70 square metres, measured inside the enclosing walls.
- Set back no less than 2 metres from the principal residential unit.
- Residential zone: no less than 2 metres from the front, side and rear boundaries.
- Rural zone: no less than 10 metres from the front boundary, 5 from the sides and rear.
- Building coverage no more than 50 per cent in a residential zone; elsewhere, per the district plan.
- Permitted only in residential, rural, mixed use and Māori purpose zones.
Miss one and the unit is not a permitted activity — it gets assessed under the district plan, which for most sites means a resource consent. The standards do not switch the district plan off either: subdivision, section 6 RMA matters of national importance, non-residential use, papakāinga and earthworks all still apply. What councils cannot refuse you on is amenity values, outdoor space, privacy, sunlight, glazing or parking. A more lenient district plan wins.
Where the two regimes disagree
Side by side, the divergences are obvious, and they are not accidents. The 2-metre setback to the principal dwelling and the 70-square-metre cap were designed to align. The rural setbacks, the coverage cap and the one-per-site limit were not. The exemption’s construction conditions have no equivalent in planning law either, which is why you can be perfectly zoned and still need a building consent over a mezzanine loft or a cladding that tips past the weight limit. Go the other way and a lifestyle block at Kūmeu or Huapai can pass every construction condition and still sit in the wrong part of its paddock.
| Test | Building Act exemption | NES-DMRU (RMA) |
|---|---|---|
| Consent removed | Building consent | Resource consent |
| Size | 70 m² or less | 70 m² or less, inside the enclosing walls |
| Storeys | Single storey, no mezzanine | Not an NES standard |
| Height / floor level | ≤ 4 m above floor; floor ≤ 1 m above ground | Not an NES standard |
| To the main house | 2 m from other residential buildings | 2 m from the principal unit |
| Boundary, residential | 2 m from legal boundaries | 2 m front, side and rear |
| Boundary, rural | 2 m from legal boundaries | 10 m front; 5 m side and rear |
| Building coverage | Not a condition | 50% max in residential; district plan elsewhere |
| Units per site | Not a condition | One per site |
| Zones | Not zone-based | Residential, rural, mixed use, Māori purpose only |
| Construction, plumbing | Cladding/framing weights, ≤ 30 fixture units, no internal pumps | Not an NES standard |
One caution about that right-hand column: “Not an NES standard” means the NES is silent, not that your district plan has nothing to say. Height and earthworks are worth a specific question before anyone draws.
Seventy square metres is where the kitchen gets decided
Here is the part nobody writes about. A residential unit only counts as self-contained if it has the lot — sleeping, cooking, bathing and toilet facilities. The kitchen is not a nice-to-have you add if there is room left. It is part of what makes the building qualify as a dwelling. And it fits inside seventy square metres, with no mezzanine to push a bed upstairs.
So the arithmetic is brutal and always the same. Bathroom, bedroom, living space, laundry somewhere, and the kitchen gets what is left — usually three to four linear metres against one wall. There is no scullery; a walk-in scullery needs floor area a granny flat does not have. One well-planned run beats a cramped U, and there are tricks for making a small kitchen feel bigger that cost nothing at the drawing stage. Stick to the standard sizes we build to — every millimetre in a filler is a millimetre not in a drawer.
The plumbing conditions that quietly design your kitchen
The exemption carries plumbing and drainage conditions that read like compliance boilerplate and are actually a layout brief. Nobody passes them on to the homeowner. They find out the day the drainlayer walks the site.
| Condition on the exemption | What it means for your kitchen |
|---|---|
| Fixture units ≤ 30 | The sink and dishwasher share a budget with the bathroom and laundry. Have the plumber count before you spec a second sink. |
| No pumped systems inside | Waste falls to the drain on gravity. This is what moves your sink off the island. |
| Main drain DN100, 1:60 min | Long runs need depth. On a flat site drainage decides where the sink goes. |
| Branch drains DN65, 1:40 min | Same for the sink branch and dishwasher tail. Short and direct beats clever. |
| No uncontrolled water heating | Hot water to the mixer comes off a controlled system. Confirm with your plumber. |
| Independent electricity supply | Oven, hob and dishwasher hang off the flat’s own supply, not a spur from the house. Size it before picking an induction hob. |
Half the granny flat jobs we quote have the sink drawn in the middle of an island, and half of those move back to the wall the day the drainlayer looks at the fall.
Passing one exemption tells you nothing about the other.
If you are going to rent it out
Nothing says the unit has to house family — you can rent it, and plenty are going up precisely for the income. Selling it separately is another matter: the NES-DMRU only applies where the unit is held in common ownership with the principal dwelling on the same site, and subdivision is expressly something your district plan still governs. A separate title means a subdivision consent.
Rent it and the Healthy Homes standards come with it, and ventilation and extraction are the kitchen’s touchpoint. In a seventy-square-metre open plan the kitchen sits in the living space, so extraction matters more, not less. A recirculating rangehood is not always sufficient on its own, and the ducted versus recirculating call is far easier before the roof goes on.
What goes wrong
None of these are hypothetical. They are the phone calls.
- Drawn to the line — two metres exactly, seventy exactly. Then the site measure comes back and there is no tolerance left.
- The owner wants it to match the house. Heavier cladding, a raked ceiling, a storage loft — each alone knocks the build out of the exemption, while the planning side never flinches.
- The sink is drawn mid-island. Someone reads the no-internal-pumps condition, works out the fall, and the layout changes at the worst moment.
- Site coverage counted from memory. House, garage, the carport that was always temporary — add seventy square metres and the site tips past 50 per cent.
- The kitchen was ordered before the PIM came back. That is a bet, not a programme.
What to ask before you sign anything
- Which zone is the site in, by National Planning Standards name — and is the district plan more lenient?
- What is the existing building coverage, measured rather than remembered, and what does it become with the unit?
- Any natural hazard, heritage or other overlay that keeps the district plan in play regardless?
- Has the designer worked to the MBIE design conditions checklist, or to an impression of seventy square metres?
- Where does the main drain run, at what depth, and how many fixture units are left under 30?
Frequently asked questions
Do I need a resource consent for a granny flat if it does not need a building consent?
Not necessarily. They are separate tests under separate Acts, so clearing one says nothing about the other. A rural-zone unit 3 metres off a side boundary, or a residential site already over 50 per cent covered, clears the building consent exemption and still needs a resource consent.
What are the NES-DMRU setbacks for a granny flat in a rural zone?
No less than 10 metres from the front boundary and 5 metres from the sides and rear, plus at least 2 metres from the principal dwelling — much further than the Building Act exemption’s 2 metres from any boundary. Miss it and the unit stops being a permitted activity, and your district plan takes over.
Does the 70 square metres include the garage?
The NES-DMRU measures floor area inside the enclosing walls, and councils commonly describe garages as sitting outside that 70 square metres. The Building Act exemption states its own separate 70-square-metre condition. The two were drafted apart, so do not assume they count a garage the same way. Put it on the PIM drawings and get it confirmed in writing.
Can I rent out a granny flat built under these rules, and sell it separately later?
Renting is fine; nothing in either regime says it has to house family. Selling it separately is different — the NES-DMRU only applies where the unit is held in common ownership with the principal dwelling on the same site, and subdivision is expressly a matter your district plan still governs. A separate title means a subdivision consent, outside both exemptions.
What does the 70 square metre limit actually do to the kitchen?
It makes the kitchen part of the living space rather than a room of its own. With no mezzanine permitted, bedroom, bathroom, living and kitchen compete for one single-storey footprint, so the kitchen typically lands at three to four linear metres with no scullery. It is materially cheaper than the same kitchen in a full house.
Send us the plan, we will price the kitchen
You do not need the consent position resolved to get a kitchen number. You need a footprint and a rough idea of where the drainage runs. Send the floor plan — a PIM-stage preliminary is plenty — with the linear metres you think you have, and a trade-priced supply-and-install number comes back inside 24 hours, plus GST. If drainage moves the sink later, we re-cut.
We build in our own workshop in East Tamaki and turn out ten-plus kitchens a week, mostly for developers and builders, which is why there is no showroom in the price. Supply and install sit under one contract and one invoice, so there is no gap between cabinetmaker and installer for your programme to fall into — and on a granny flat, where the LBP is co-ordinating a short critical path, that matters. To sanity-check the budget, what a kitchen costs in Auckland this year sets out the bands.