Building a granny flat? Why starting with quality matters more than ever
New legislative changes expected to come into force in early 2026 will create a building consent exemption for small standalone dwellings up to 70 square metres - what many of us call granny flats. This is opening up exciting possibilities for whānau to add secondary dwellings to their properties.
But in the rush to take advantage of this opportunity, there's a crucial conversation we need to have: if someone you love is going to live in this space full-time, how do we ensure it's truly a healthy home?
Understanding the building consent exemption
The proposed legislation streamlines the process for building small standalone dwellings, though it still requires licensed professionals, council notification and Building Code compliance. You can find the full requirements here.
The consent exemption creates a framework, but the choices you make within that framework will determine whether this becomes a space that truly supports whānau wellbeing.
Multigenerational living deserves more
The reality for many whānau is beautiful and complex. Perhaps your parents are ageing and you want them close by, but independent. Maybe you're creating a space for an adult child to gain their footing, or providing a home for a family member with health considerations. These aren't short-term solutions, they are homes where the people you care about will wake up every morning, cook their meals and spend their winters.
When housing vulnerable family members (elderly parents, those with respiratory sensitivities, or young families), the quality of that indoor environment becomes critical. Poor ventilation, inadequate insulation and moisture issues create genuine health risks.
Laying foundations for multigenerational health
At Toa Homes, our mission centres on laying the foundations for multigenerational health. The choices we make today in how we build have ripple effect on generations to come.
This isn't just about meeting minimum standards. It's about creating spaces where our whānau can truly thrive, where the air they breathe supports their wellbeing, and where the building itself becomes a foundation for health rather than a source of illness. Learn more about what makes a truly healthy home.
Quality where it counts, flexibility where you need it
We offer two set designs that work perfectly as consent-exempt granny flats: our Tupu design (35m², 1 bedroom) and Oke design (48m², 2 bedrooms). Both use our innovative panel system with a flexible approach that works within the new consent-exempt framework.
We provide the structural shell (the foundation, framing and airtight envelope) assembled on-site. This gives you a healthy, solid base: proper moisture management, quality framing and an airtight structure that will perform well for decades. From there, you can work our team or with other licensed professionals to complete the lining and fit-out. See how James and Eva approached their build.
Why the shell matters for a healthy granny flat
The structural envelope is where building science matters most. It's where moisture gets managed, where thermal performance is established, and where the long-term durability of the building is determined. These aren't areas where you want to cut corners, especially when the health of your whānau members is at stake.
Getting this foundation right means:
Proper ventilation systems that prevent mould and moisture buildup
Insulation that keeps the space warm and dry during New Zealand's damp winters
Airtightness eliminates leaks and protects the building structure and indoor air quality
Choosing quality for your secondary dwelling
Yes, the new building consent exemption makes small standalone dwellings more accessible. But our whānau deserve a space that supports their wellbeing, not one that becomes a source of health concerns down the track.
If you're planning a granny flat under the upcoming legislation, we'd love to talk with you about how our panel system can provide both quality and flexibility. Because the people living in these spaces deserve both. Together, we can lay the foundations for multigenerational health.
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Frequently asked questions about granny flats in Aotearoa
What size granny flat can I build without consent in New Zealand?
Under the proposed legislation expected in early 2026, you'll be able to build a standalone secondary dwelling up to 70 square metres without a traditional building consent. However, you'll still need to notify your council, use licensed professionals, and ensure full Building Code compliance. Our Tupu (42m² external) and Oke (58m² external) designs both fall within this exemption. View full requirements.
Can I build a granny flat myself in New Zealand?
The new consent exemption requires all work to be carried out or supervised by licensed building professionals (LBPs, licensed plumbers, electricians, etc.).
How do I ensure my granny flat is a healthy home?
Meeting minimum Building Code requirements is just the starting point. A truly healthy granny flat needs proper ventilation to prevent mould, quality insulation for warmth and dryness, and excellent airtightness. These fundamentals are established in the structural shell (the foundation, framing and building envelope). This is why starting with a quality shell matters so much, especially when vulnerable whānau members like elderly parents or young families will be living there. Learn more about building healthy homes.
How much does a 70m² granny flat cost in New Zealand?
Costs vary based on location, site conditions and the level of finish you choose. Our Tupu design (35m² internal) starts from $220,000 + GST for a full build, while our Oke design (48m² internal) starts from $262,000 + GST.
We also offer flexible options where we provide the structural shell and you complete the fit-out with licensed professionals, helping balance quality with budget. View our full pricing and designs or get in touch to discuss your specific project.
