New Granny Flat Rules Take Effect
New Zealand’s granny-flat reforms took effect on 15 January 2026, introducing a building-consent exemption for qualifying new, standalone homes of up to 70 square metres. The change created another route to building a smaller home, with professional design, Building Code compliance and suitable services remaining central to the process.[1]
This article explains the original January 2026 reform. The exemption was subsequently updated in October. Read the October 2026 News update for those changes, and use our comprehensive granny-flat rules and wastewater guide for current planning.
For homeowners considering accommodation for family, a smaller place to live or an additional dwelling on an existing property, the reform opened a new planning conversation.
The starting point became more than whether a small home could fit on the section. It also became a question of whether the proposed building, its location and its essential services could meet the conditions of the new exemption. The building-consent exemption applies to certain wholly new, single-storey, standalone dwellings with a floor area of no more than 70 m². The design, construction and professional involvement must meet the exemption conditions. The Building Code continues to apply. The exemption changes the approval process for qualifying work; it does not create a lower construction standard.[1] For buyers, this makes the proposed design and the building supplier’s documentation important. A suitable floor area is a starting point, rather than confirmation that the complete project qualifies.What the January reform introduced
The practical opportunity: consider the home and its servicing together, rather than purchase the building first and investigate sanitation afterwards.
Two reforms, with different purposes
A separate national planning framework also commenced on 15 January 2026: the National Environmental Standards for Detached Minor Residential Units.
These standards provide a permitted-activity pathway for qualifying minor dwellings where the relevant conditions are satisfied. The planning rules and the building-consent exemption operate independently. Meeting one does not automatically establish that the other has been met.[2][3]
A practical way to approach the distinction is to ask two questions: Can this home be built using the exemption, and can this dwelling be established on this particular property?
Professional input remains part of the process
Under the January process, homeowners using the exemption had to obtain a Project Information Memorandum, commonly called a PIM, from their council before building work started. Completion documentation also had to be provided, including the relevant plans, professional records and certificates.[2]
Our recommendation is to establish those responsibilities early. The building supplier, designer and installation team should understand who is checking the site, coordinating services and supplying the final project records.
Water and wastewater belong in the initial design
A smaller home still needs safe water and a suitable sanitation arrangement. Building Code requirements address both water supplies and the safe management of wastewater from sanitary fixtures and appliances.[4]
For WCTNZ®, this is an opportunity to consider sanitation as part of the home’s design rather than as a fixture selected at the end.
A waterless composting toilet can form part of that discussion. New Zealand’s Building Code recognises non-water-borne sanitation where a healthy and safe disposal system is provided. The remaining household wastewater needs its own appropriate arrangement.[5]
Our advice is to discuss the toilet, shower, kitchen and laundry together. That gives the project team a complete picture of what the home will produce and how each waste stream will be managed.
A practical starting point for homeowners
Before committing to a building, bring the proposed floor plan, intended occupancy and available property information to the people designing and supplying the project.
At WCTNZ®, we recommend comparing sanitation options while the bathroom layout, foundations and service routes are still being considered. This is the stage to establish whether a waterless composting toilet and an appropriate greywater arrangement could suit the home.
For the current rules and a fuller explanation of servicing options, read our 70 m² Granny Flat Rules, Myths and Wastewater Options guide.
Explore sanitation options for your smaller home
Share your proposed location, occupancy, floor plan and available services with WCTNZ®. We can help with product selection and the information your project team needs.
Discuss your project with WCTNZ®
