PropertyMetrics

Quick Answer

From 15 January 2026, you can build one detached granny flat of up to 70m² on most residential, rural, mixed use and Māori purpose zoned sections in New Zealand without resource consent, under the national environmental standard for detached minor residential units (SL 2025/315). A companion Building Act exemption removes building consent for a compliant single-storey unit. The section must already have a main house, the unit must sit at least 2m from boundaries and the main house (residential zones), total building coverage must stay at or under 50%, and district plan hazard rules, covenants, and cross-lease or unit title arrangements can still require professional input.

1
What Changed

What Changed in January 2026?

New Zealand used to leave granny flats entirely to each district plan — the same unit could be a permitted activity in one city and need full resource consent one street over the council boundary. Two national rule changes replaced that patchwork.

First, the Resource Management (National Environmental Standards for Detached Minor Residential Units) Regulations 2025 (SL 2025/315, in force 15 January 2026) make a compliant granny flat a permitted activity nationwide in eligible zones. If the standards are met, no resource consent is needed and the council cannot require one.

Second, a companion Building Act exemption removes the need for building consent for a compliant single-storey unit — the part of the process that used to add months and thousands of dollars before a spade hit the ground.

70m²
Maximum floor area under the national standard
1 per site
One detached minor unit, and the site must already have a main house
15 Jan 2026
Date the national standard came into force
Two rule sets, commonly confused

The RMA standard (resource consent) and the Building Act exemption (building consent) are separate. The 70m² cap and the setbacks come from the RMA standard. The single-storey, 4m height and 1m floor-level limits come from the Building Act exemption. A unit can pass one and fail the other — a two-storey 65m² unit needs no resource consent in an eligible zone, but it does need building consent.

2
The Standards

The Size and Placement Standards

These are the actual standards, drawn from the legislation itself. Meet all of them and the unit is a permitted activity in an eligible zone.

StandardRequirementSource
Floor area
70m² or less
SL 2025/315 reg 6(a)
Units per site
One, fully detached, with a main house already on the site
reg 3(1), reg 5(1)
Distance from the main house
At least 2m
reg 6(c)
Boundary setbacks — residential zones
At least 2m from front, side and rear boundaries
reg 6(d)(i)
Boundary setbacks — rural zones
10m from the front boundary, 5m from side and rear
reg 6(d)(ii)
Building coverage — residential zones
All buildings together cover 50% of the site or less
reg 6(b)(i)
Building consent exemption (separate test)
Single storey, height 4m or less, floor level no more than 1m above ground
Building Act 2004 exemption
Coverage catches more sections than the 70m² cap does

On a typical 450–600m² urban section with an existing house, garage and sleepout, total building coverage is often already near 40–45%. Adding 70m² can push past the 50% limit even though the unit itself complies. This is the single most common reason an otherwise-eligible section fails screening in our data.

3
Eligible Zones

Which Zones Qualify?

The standard applies in four zone categories, mapped from each district plan to the national planning framework:

  • Residential zones — the main case: single house, mixed housing, medium and high density zones
  • Rural zones — with the larger 10m/5m setbacks
  • Mixed use zones — using the district plan’s own setbacks and coverage
  • Māori purpose zones — using the district plan’s own setbacks and coverage

It does not apply in:

  • Business, commercial, industrial, town centre and city centre zones
  • Open space, conservation and special purpose zones
The zone must be operative

Where a district plan is proposed, under appeal, or mid plan-change, the zone’s status matters — a site whose zoning is not yet operative deserves a planner’s eyes before you rely on the standard. Our screening checks the plan’s version status for exactly this reason.

4
Watch-outs

What Can Still Stop You

The headline rule is generous, but regulation 7 of the standard preserves the district plan’s rules on hazards and a handful of other matters. In practice these are what catch real sections:

  • Natural hazard overlays. Flood plains, coastal inundation, liquefaction and slope-instability layers still apply. In Christchurch and Tauranga, liquefaction management zones cover much of the city — an honest screening there often says “get a geotech report”, because that is genuinely the right answer.
  • Heritage, character and special overlays. Viewshafts, heritage areas, notable trees and character precincts carry their own rules that the standard does not override.
  • Title covenants. A registered covenant — a no-further-building or single-dwelling covenant is common in newer subdivisions — can prevent the build regardless of zoning. Covenants sit on the title, not in the district plan, so zoning maps will not warn you.
  • Cross-lease and unit titles. The standard is written for the straightforward fee simple case. On a cross-lease you generally need the other lessees’ consent and possibly a flats plan update; on a unit title, body corporate rules apply.
  • Steep sites. A sloping section brings earthworks and foundation questions the exemption does not cover. We flag anything over 15° for geotechnical review.
  • Services and infrastructure. Wastewater and stormwater capacity, and the cost of new connections, are practical constraints the planning rules leave to you and your council.
Development contributions can still apply

Even when no consent is needed, councils can charge development contributions on a new dwelling unit under the Local Government Act. Depending on the council this can run to five figures. Check the council’s development contributions policy before you budget the project.

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Check Your Section

Check Your Own Address, Free

Reading the rules tells you what’s possible in general. Whether your section qualifies depends on its zone, its exact parcel geometry, what’s already built on it, its slope, its tenure, and every overlay that touches it. That is precisely what our feasibility screening computes — live against LINZ parcel data and each council’s own planning layers, with every rule cited to its source.

Screening is free and unlimited, and covers granny flats, adding multiple dwellings, and subdivision. It currently runs in nine councils:

Screen your section for a granny flat — free
6
FAQ

Granny Flat Rules — Common Questions

Do I need any consent at all?
Often no. A unit that meets the national standard needs no resource consent in an eligible zone, and one that also fits the Building Act envelope (single storey, 70m², under 4m high, floor within 1m of ground) needs no building consent. Both tests must be met independently, and the exemption still comes with obligations — check the Building Act exemption’s notification and professional requirements with your council before starting.
Can the granny flat be rented out?
Yes. Nothing in the standard restricts who lives in the unit — family, boarders or tenants. As a rental it is subject to the same Healthy Homes and tenancy law as any other dwelling, and rental income is taxable as usual. For investors, a compliant granny flat is one of the cheapest ways to add a second income stream to an existing section.
Does the 70m² include decks and garages?
The 70m² cap applies to the unit’s floor area. Uncovered decks are generally not floor area, but an attached garage is. If the design is near the cap, have the floor-area calculation confirmed before committing — measurement conventions differ between plans.
My section is in a flood or liquefaction overlay. Is it game over?
No — it means the district plan’s hazard rules still apply to the build, which usually translates to an engineering assessment and possibly consent for that aspect. Much of Christchurch and Tauranga sits in liquefaction management zones and granny flats are still built there routinely; the foundations are just engineered accordingly.
Can I subdivide the granny flat off later?
Not under this standard — it permits the building, not a subdivision. Subdividing to give the unit its own title is a separate consent process under the district plan’s subdivision rules, with its own minimum lot sizes. Our feasibility tool screens subdivision as a separate check if that is the long-term plan.
What does a granny flat cost to build in 2026?
Budget ranges vary widely with site and spec, but most 50–70m² builds land somewhere between $150,000 and $350,000 including site works and services. Prefab and transportable units sit at the lower end. Development contributions and service connections come on top — get those numbers from your council early.

See what your section could take

Free screening against the actual rules — the 70m² standard, your zone, your setbacks, your hazard overlays — computed for your address in under a minute, with every rule cited.

This guide is general information, not legal, planning or building advice. It summarises the Resource Management (National Environmental Standards for Detached Minor Residential Units) Regulations 2025 (SL 2025/315) and the related Building Act 2004 exemption as at July 2026. Rules change and every site is different — verify current requirements on legislation.govt.nz and building.govt.nz, and engage a licensed building professional, planner or lawyer before committing to a build. Our feasibility screening is a desktop assessment from official data, not a substitute for professional advice.