The Granny Flat Rules Just Changed

A minor dwelling is a self-contained home on the same site as your main house. Its own kitchen, bathroom and living space, built to the same standards as any habitable building. People use them for parents, adult kids, a rental, or simply more room to move.

The rules around them changed on 15 January 2026, and the change is bigger than most Northland homeowners realise.

The exemption is live, not proposed

Until this year, every minor dwelling in Northland needed a building consent, and often a resource consent too, whether you're in Whangārei, the Far North, or Kaipara. That's no longer automatic.

Under new amendments to the Building Act, small standalone dwellings up to 70m² can now be built without a building consent, provided they meet a specific set of conditions and are designed and built (or supervised) by a Licensed Building Practitioner. A companion change to the Resource Management Act does something similar on the planning side, exempting qualifying builds from certain District Plan rules.

This isn't a future possibility. It's the current pathway.

What qualifies

The conditions are set nationally, so they apply the same way whether your site is in Whangārei, Kerikeri, or Dargaville. They're worth reading properly before you get attached to a design:

• New, standalone, single storey

• No more than 70m² floor area, including any internal garage

• At least 2m from any other building or legal boundary

• Lightweight steel or timber framing, lightweight roof cladding

• Wall cladding no heavier than 220kg per square metre

• Connected to council water and wastewater where available, or a compliant on-site system

• No level-entry shower requiring a waterproof membrane

• Designed and built, or supervised, by an LBP

Miss one of these and you're not in exemption territory anymore. You're back to a full building consent.

Consent isn't gone, it's just moved

The exemption removes a building consent. It doesn't remove council involvement.

You still need a Project Information Memorandum (PIM) before you start, and you still need to notify your council once the work is done. The application process differs slightly between Whangārei District, Far North District, and Kaipara District councils, but the PIM itself does the same job everywhere: it's where site-specific issues show up. Hazard overlays, heritage areas, service connections, whether your zoning actually allows what you're picturing.

Resource consent can still be triggered separately, particularly if your site sits in a coastal or flood-prone area, or if the property is already tight on setbacks or site coverage. The building exemption and the resource consent question are two different tests. Passing one doesn't automatically clear the other.

There's also a two-year clock. Once your PIM is issued, the build needs to be finished within two years, or you'll need an extension from council before that window closes.

The part people skip: does your site actually work?

The framing rules are simple enough. What trips people up is everything underneath them, the stuff a set of Building Code compliant plans won't tell you on their own.

Boundary distances, access, existing services, ground conditions, whether a second dwelling changes your site coverage past what's permitted. On a lot with any complexity, this is where a project either moves smoothly or stalls for months waiting on information that should have been gathered at the start.

The building might be simple. The site rarely is.

Where we fit

We do the groundwork before the exemption process starts: confirming what your site can actually support, working through the PIM requirements with your local council, and producing a design that's genuinely built to sit inside the 70m² lightweight-construction rules rather than one that looks compliant on paper and unravels once someone checks the details.

If you're weighing this up for a specific site, that's a conversation worth having early.