Legal advice – What can you build without consent?

For many homeowners, putting a tiny house in the backyard or creating a granny flat is an attractive way to make better use of their property. Recent changes to New Zealand’s building and planning rules have made some projects simpler, but “no building consent” does not mean “no legal requirements”.

The biggest change for people considering a granny flat came into effect on 15 January 2026. Certain granny flats of up to 70 square metres can now be built without a building consent, provided they meet exemption requirements.

The dwelling must be new, standalone and one-storey, have a simple design and comply with the Building Code. Appropriately licensed building professionals must also carry out or supervise the work.

MBIE has published new guidance on foundations for granny flats built under the exemption. Further changes to the granny flat exemption are due to take effect on October 8, including changes relating to the building products that can be used and servicing options.

Even where a building consent is not required, there are still steps to follow. A project information memorandum (PIM) must be obtained from Council before work begins on site, and information must be provided to Council at various stages of the project.

There is also a separate question to consider: is resource consent needed?

Under new national environmental standards, a qualifying detached minor residential unit of up to 70 square metres can be a permitted activity in residential, rural, mixed-use and Māori-purpose zones, meaning resource consent may not be required.

However, the unit must meet the relevant planning standards, including requirements for setbacks, building coverage and distance from the main dwelling. A minor amendment came into force last month clarifying how the existing setback distances are measured. Other rules and site-specific constraints can still apply, including local district and regional planning rules.

Although these changes give additional flexibility, they are not a complete green light to build anything, anywhere on your property. A granny flat may be exempt from both building consent and resource consent, but only if it meets all the relevant requirements.

If it does not, one or both consents may still be needed. The rules can also vary depending on the property’s zoning and location, so it’s important not to assume the new exemptions apply to every property.

So, what about a tiny house? Simply calling something a tiny house does not mean it is exempt from building consent requirements.

A tiny house is generally understood as a small building designed or used for living in, rather than being a separate legal category. Whether consent is needed depends on what is being built, how it is constructed and how it will be used.

For example, some small, detached buildings may not require consent if they meet certain requirements. However, adding a kitchen or bathroom can take the work outside that particular exemption and require building consent. It may also trigger plumbing, drainage, planning, development contribution or change-of-use requirements, depending on the circumstances.

For Kaipara property owners, the important point is that there is no single “no consent needed” rule. Building consent and resource consent are separate requirements, and exemption from one does not automatically mean exemption from the other. Other site-specific factors can also affect what you can build, particularly in areas affected by natural hazards or other planning controls.

Before your builder arrives on site, it is worth checking what rules apply to your property and making sure you have any required consents, exemptions or other approvals in place.

A little homework at the start can help avoid an expensive surprise later, particularly when it comes time to sell, refinance or insure your property. However, figuring out the rules on your own can be time-consuming and complicated, so it is worth seeking legal advice if you are unsure. The team at WRMK Lawyers can discuss your plans and help you understand the legal requirements that apply to your property.