New opportunities for granny flats under the updated consent exemption

For many property owners, the appeal of a granny flat is easy to understand. A small standalone dwelling can create space for extended family, support ageing in place, generate rental income, or simply make better use of existing land. The recent changes to New Zealand’s building legislation are intended to make that option more accessible by allowing certain granny flats of up to 70 m² to be built without a building consent.

That reform is significant, but it should not be misunderstood. The new exemption, which took effect on 15 January 2026, does not remove the need for careful design, planning and compliance. Instead, it changes the route by which a qualifying project can proceed. For owners, developers and builders, the practical message is that while the process may be faster in some cases, the margin for error can be much narrower.

Before building granny flats in New Zealand: key requirements

Although the exemption removes the need for a building consent in qualifying cases, it does not allow a project to begin informally. Owners still need to engage with their local council at the outset and obtain the required project information documentation before work starts. They also need to think early about the site itself, including natural hazards, access, services, and whether any planning approvals may still be required. In practice, those issues are often the difference between a straightforward project and one that becomes delayed or more costly than expected.

The reform also places greater weight on the professionals involved. A granny flat built under the exemption must still comply with the Building Code, and restricted building work must still be designed and carried out by the appropriate licensed registered practitioners. That means the choice of designer, builder, plumber, drainlayer, electrician and gasfitter remain critical. Where the cost of the work reaches the statutory threshold, a written building contract is also required. Seen in that light, the exemption is less about cutting corners and more about shifting responsibility onto the people delivering the project.

Which granny flats qualify for the consent exemption?

One of the most important points for owners is that the exemption is tightly defined. It applies only to certain newly built, standalone, single-storey dwellings that fall within strict design and construction parameters. Size, setbacks, structural systems, roof and cladding weights, plumbing arrangements, and internal features all matter. If a project falls outside those requirements, the exemption will not apply, and a building consent will still be needed.

Broadly, the exemption is aimed at modest, low-risk structures built using conventional lightweight materials and straightforward servicing arrangements. Features that increase complexity or risk can take a project outside the exemption. That is why early design review is so important: a scheme that looks simple at first glance may still require a consent once the details are tested against the legislation.

For that reason, eligibility should be treated as a threshold issue rather than an assumption. If there is any doubt, obtaining advice before construction begins is likely to be far less costly than dealing with a non-compliance issue later.

Building without consent: what changes for construction?

One practical consequence of the new regime is that owners should not expect the same inspection pathway they would see on a consented project. That makes internal quality assurance much more important. Builders and owners will need confidence that:

• critical stages of the work have been properly checked;
• products and materials match the approved design intent; and
• the completed dwelling can be supported by a reliable documentary record.

This is especially important where changes arise during construction. Even relatively minor variations can affect whether the exemption remains available. A change in footprint, materials, servicing or internal layout may appear commercially sensible on site, but it can have regulatory consequences if it pushes the build outside the permitted criteria. Thorough records of design decisions, work carried out, product information and completion documents will also matter later, particularly for lending, insurance and future sale of the property.

After building: compliance requirements for granny flats

Completion is not the end of the process. The exemption comes with strict timeframes and documentation requirements, including the need to provide final plans and professional records within the prescribed period after the work is finished. If development contributions are payable, those must also be addressed. Missing these steps can create unnecessary risk and, in some cases, expose an owner to enforcement issues or practical difficulties later on.

Importantly, a granny flat built under the exemption will not follow the usual code compliance certificate pathway. Instead, the relevant documentation is retained on the property record. That means the quality and completeness of those records can become significant later, particularly if the property is refinanced, insured or sold. From a client perspective, the administrative side of the project is therefore just as important as the physical build itself.

Why getting the detail right matters

A useful reform, with clear limits

The new granny flat exemption is a welcome development for owners and the wider construction sector. It reflects a policy choice to make smaller dwellings easier to deliver and may help unlock more flexible housing options across New Zealand. For many clients, that will be an attractive opportunity.

At the same time, the legislation is not a free pass. The exemption is carefully constrained, and projects that do not fit within it will still need to follow the ordinary consent pathway. Even where the exemption is available, success will depend on careful upfront advice, sound contracting, disciplined construction practices and complete records.

For clients considering a granny flat project, the key question is not simply whether a consent can be avoided. It is whether the project has been structured in a way that makes it compliant, buildable and durable from the outset. That is where early legal, planning and construction input can add real value.

Paula Nicolaou, Partner Wynn Williams’ Construction, Infrastructure & Projects team.

Keriana Snodgrass, Law Clerk – Wynn Williams’ Construction, Infrastructure & Projects team.