NZ Granny Flat Rules 2026 (Wellington Edition): What’s Changed and What to Check Before You Build

Sheryl Sua
Jan 21
4 min read

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If you’ve been thinking about adding a granny flat to your property, 2026 has opened the door wider.

Since 15 January 2026, New Zealand’s new granny flat rules are officially in effect. The goal is to make it easier for homeowners to build a small standalone dwelling up to 70m², with fewer consent hurdles in the right situations.

But if you’re in Wellington, there are a few local realities worth factoring in early, because the region’s terrain, wind exposure, and site constraints can affect feasibility even when the national rules are designed to simplify things.

This blog breaks it down in plain English.

What changed from 15 January 2026?

There are two key shifts:

1) Some granny flats may be exempt from building consent

Certain granny flats can now be built without a building consent, as long as they meet the exemption criteria and still comply fully with the New Zealand Building Code.

2) Planning rules may be more flexible in some cases

National planning standards are intended to make detached minor dwellings easier to deliver across more zones, where the conditions are met. This may reduce the need for resource consent in some situations, but it still depends on your site and zone.

The big number: 70m²

The main threshold is 70 square metres.

If the granny flat is 70m² or less, and it’s new, standalone, and single-storey, it may qualify under the building consent exemption (if all other conditions are met).

That’s enough space for a practical layout with a kitchen, bathroom, living area, and one or two bedrooms, depending on the design.

“No building consent” doesn’t mean “no rules”

Even if your build qualifies for the exemption, it still needs to be done properly and documented correctly.

A granny flat built under the exemption still must:

fully comply with the NZ Building Code
meet the exemption conditions (including size, design and structure type)
be completed to a professional standard
be supported by documentation for council records, insurance, and resale

So, while the process might be simpler, the expectations around quality and compliance are the same.

Kitchens and toilets: do you need building consent if you add plumbing?

Installing a kitchen and a toilet (including plumbing) does not automatically mean you need a building consent.

If the granny flat is a new, standalone, single-storey dwelling of 70m² or less, and it meets the exemption conditions, it may still qualify without building consent, even with full kitchen and bathroom facilities.

The important catch is that plumbing and drainage still need to be done correctly and by the right qualified people (for example, a registered plumber/drainlayer) with all paperwork. The build still needs to comply with the Building Code, and council notifications still need to be completed before and after the work.

The Wellington-specific checks that matter

Wellington is a fantastic place to build, but it has a few conditions that can change the scope of a project quickly. These are the items we recommend checking upfront.

1) Steep sites and retaining

A lot of Wellington properties are on slopes. This can affect excavation, foundation design, access, and retaining requirements. Even if the granny flat itself is small and simple, the site works may not be.

2) Wind exposure

Wellington’s wind isn’t a secret, and higher wind zones can influence structural design and fixings. That doesn’t stop you from building, but it may affect what qualifies as “simple”, depending on the final design and location.

3) Ground conditions and natural hazards

Some areas have known geotechnical challenges, and it’s common to need a good understanding of ground stability, drainage, and stormwater paths before building on a site. If your property sits in an area with hazard overlays, it’s important to factor that into the early feasibility stage.

4) Access and logistics

Even where the building itself is straightforward, getting materials and trades onto a Wellington section can be tricky. Tight driveways, limited space, and tricky access can all affect cost and build time.

5) Services connections

Wastewater, stormwater, and water supply need to be planned properly. A granny flat isn’t just a room; it’s a dwelling, so you want services designed correctly from day one to avoid expensive rework later.

You still need to notify the council

Even if you don’t need a building consent, councils still need records of the dwelling.

That typically means:

notifying your council before you start (submit your plans; they will be able to give guidance before any work starts). Work can only commence once the Council has issued a Project Information Memorandum (PIM)
providing the required documentation within 20 days after completion

This is an important part of keeping everything above board for future sale, insurance, and property documentation.

What this means for Wellington homeowners

For many people across Wellington, these changes make it more realistic to add a second dwelling for:

parents or extended family
adult kids wanting independence while staying close
rental income
long-term flexibility and property value

The biggest benefit is that a well-planned, code-compliant granny flat can now be simpler to deliver than before, provided the site and design stay within the exemption requirements.

Please see the exemption guidelines for more information: Granny Flats Exemption Guidance

Practical advice if you’re planning a granny flat in Wellington

If you’re considering a build in 2026, these steps will save time and stress:

Confirm your design meets the exemption conditions
70m² is only one part of it. The overall design needs to qualify.
Do an early site check before spending on full plans
In Wellington, steepness, wind exposure, hazards, and access can make the biggest difference.
Use qualified professionals and keep a solid paper trail
Even with an exemption, the build must be compliant, professionally completed, and documented properly.

Ready to explore a granny flat in Wellington?

Orkney Group can help make the new 2026 granny flat process far more straightforward, from site feasibility and requirements through to coordinating the right trades and delivering a compliant, high-quality build.

Get in touch with us today to start the ball rolling, and we’ll help you explore options, costs, and next steps!