Consent-Free Granny Flats in New Zealand:
What You Need to Know.
The Government’s decision to allow granny flats of up to 70m² to be built without a building consent has been welcomed by many as a step toward faster and more affordable housing. On the surface, it sounds like a great idea. Less paperwork, fewer delays, and lower upfront costs should make it easier for families to create additional space for aging parents, adult children, guests, or rental income. In a country where housing costs continue to climb, anything promising simplicity and affordability is naturally going to attract attention.
And to be fair, reducing unnecessary red tape is not a bad thing. The building process in New Zealand can absolutely become overcomplicated, expensive, and painfully slow at times. Nobody enjoys spending months navigating paperwork only to receive an invoice large enough to trigger temporary emotional damage. But while the intention behind the policy is positive, there is a risk this could open a bit of a can of worms.
The biggest issue is that removing the building consent process does not remove the requirement to comply with the Building Code. These granny flats still legally need to meet code. The obvious question then becomes: who is actually checking? That’s where things become uncomfortable. The consent process, despite its frustrations, at least creates a formal layer of oversight. Remove that layer, and there is a real possibility more poorly designed and poorly constructed buildings begin slipping through unnoticed. Unfortunately, New Zealand already has a history of learning expensive lessons when building quality and oversight are treated too casually.
There is also a bigger underlying problem here: the Building Code itself should not really be the benchmark we aspire to anyway. Minimum code is exactly that, minimum. In many areas, New Zealand housing standards still lag well behind international best practice. Compared with higher-performing homes overseas, much of our housing stock remains ‘under-insulated,’ thermally inefficient, prone to overheating, and heavily reliant on mechanical heating just to remain comfortable. Designing purely to minimum code is a bit like aiming to pass an exam with 50%. Technically you passed, but nobody’s framing the result on the wall.
The practical reality is that good buildings come from good design, not simply fewer regulations. One example of this tension is something as simple as eaves. Larger eaves are one of the most effectively simple design tools available. They help reduce summer overheating, protect cladding from weather exposure, improve durability, and improve comfort year-round. Yet in cities such as Christchurch, once eaves extend beyond 0.6 metres, the additional area is counted toward site coverage calculations.
The problem is that 0.6 metres is often not enough to provide optimal shading. Depending on orientation and design, effective eaves may need to be closer to 0.7 to 0.9 metres to properly control summer sun. Ironically, trying to design a better-performing building can end up triggering a resource consent because the “extra” eave area pushes the project over site coverage limits. So, you can end up in the bizarre situation where poor-performing design slides through easily, while thoughtful design gets penalised with extra cost, delays, and planning risk. That’s a frustrating contradiction.
Even with the building consent exemption, many people will also discover there are still significant constraints attached. A Project Information Memorandum (PIM) is still required, and District Plan controls around setbacks, recession planes, height limits, and site coverage still apply. In practice, this means fitting a functional, comfortable, well-performing home under 70m² can become surprisingly restrictive. And when space gets tight, compromises usually follow. Bedrooms shrink, storage disappears, windows get reduced, eaves get trimmed back, and thermal performance gets value-engineered down. Suddenly the “affordable” granny flat starts becoming a small box designed around compliance limits rather than actual liveability. That’s where the risk sits with policies like this. Sometimes they unintentionally encourage the cheapest possible outcome instead of the best long-term outcome. Saving $4,000 to $5,000 on building consent fees may sound like a major win initially, but without proper oversight those savings can quickly become fool’s gold. The risk doesn’t disappear; it simply shifts. Liability, construction quality, future compliance issues, and performance problems may ultimately land on unsuspecting owners years later.
It will also be interesting to see how this plays out during future property sales. Banks, insurers, and valuers tend to become nervous whenever there’s uncertainty around compliance, documentation, or construction quality. Even if these granny flats are technically legal, there may still be additional scrutiny around how they were designed, documented, and built. Realistically, buyers are likely to ask questions too. Who designed it? Who checked it? Was it built properly? Does it actually perform well? Those questions matter, particularly as people become more aware of issues like condensation, overheating, durability, and energy efficiency. That’s why our recommendation would still be to invest in good design from the start. A well-designed granny flat can be far more than just “extra space at the back of the section”. Done properly, it can become a genuinely comfortable, healthy, resilient small home that performs well for decades. Smaller homes actually have huge potential to perform exceptionally efficiently because every design decision matters more.
There is also no reason granny flats should settle for minimum standards simply because they are small. A high performing “Super Granny Flat” designed to at least a ‘Base’ Superhome standard could provide excellent thermal comfort, lower running costs, healthier indoor air quality, and much better long-term durability. More importantly, it creates a home where people genuinely enjoy living, whether that’s aging parents, family members, or future occupants.Good housing should not just be about building faster or cheaper. It should still be about building well. Saving money upfront is great, but nobody wants Grandma discovering her flat turns into a condensation box every winter.
