Granny flats: What you need to know

As of January this year, homeowners can build a small standalone dwelling up to 70sqm on their section without a building consent. The Government has removed the need for building consents as a way to speed up development of small homes.

We first spoke about the proposed changes back in 2024, and now that the changes are in effect, it’s good news for tradies, but that doesn’t mean it’s open season on granny flats, tiny homes and other minor dwellings. There are still a number of conditions that have to be met. It’s essential to know these conditions to avoid landing in trouble later.

What the exemption allows

A granny flat can now be built without building consent if it’s simple in design, built to the Building Code, and the building work is carried out or supervised by licensed building professionals (LBPs). Homeowners also have to notify the council before work starts and once it’s finished, using a project information memorandum (PIM). This process requires them to provide key documentation (plans, product certificates) and advise of any changes to land contours, connections to public utilities like water and wastewater pipes, new vehicle access and so on.

The PIM is for council records only, and is not a consent. It’s easy to hear “no consent” and assume “no constraints”. However, to be able to use the exemption, the dwelling must meet the following criteria:

Maximum net floor area: 70sqm or less, including internal garaging
Maximum height: 4m above the floor level
Floor level: No more than 1m above ground
Minimum 2m from any legal boundary or structure
Roofing must be lightweight (less than 20kg per sqm), framing must be light steel or timber framing and all cladding must weigh less than 220kg per sqm
Independent electricity and gas point of supply (if gas used)
Electric or gas heating

These rules mean that two-storey dwellings are not included, and it could also rule out building on sloping land, where floor levels may need to be raised. Plumbing and drainage must also be compliant with the acceptable solutions for clauses E1, G12 and G13 of the Building Code. Systems must connect to network utility operator services where available. Where these aren’t available, onsite water systems are exempt from requiring a building consent.

Understanding the risks

As noted by Karel Boakes, President of the Building Officials Institute of NZ (BOINZ), where councils once checked compliance through formal consent processes, much of that responsibility (and risk) is now on homeowners, builders and designers. This makes it even more important to use products correctly, choose products with robust warranties, and have builder’s insurance or professional indemnity insurance.

Because councils aren’t checking compliance upfront, it’s easier to make mistakes. These could be building over boundaries, forgetting to check for exposure to natural hazards, not making the required development contributions, or overlooking covenants, easements and the need for resource consent under other national standards, such as contaminated land rules. As Boakes points out, any one of these can push a build back into a full consent process after construction has already started, or see expensive rebuilds required.

It could also make it difficult, if not impossible, for the homeowner to obtain insurance or finance, or sell their property down the line.

MBIE has some very useful guidance and checklists to help get it right first time. For more information, visit the MBIE website.

Granny flats: What you need to know
2 April 2026

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Granny flats: What you need to know 2 April 2026

Explore more Trade News >

Granny flats: What you need to know
2 April 2026