Do I Need Building Consent for a Granny Flat?
If you've heard that you can now build a granny flat in Canterbury without building consent, you've heard correctly.
Sort of.
Since 15 January 2026, New Zealand has had a building consent exemption that allows some small standalone homes of up to 70m² to be built without going through the normal building consent process. See MBIE Granny Flats Exemption Guidance.
That's genuinely good news for people wanting to build a smaller home on their property.
But there's one very important bit that sometimes gets lost in the headlines:
No building consent does not mean no rules, no council involvement or no professional oversight.
There are still requirements your home, your site and your build need to meet.
So, let's make the whole thing a little less confusing.
What are the new granny flat rules?
The new exemption creates another pathway for building certain small homes.
Previously, building a self-contained granny flat generally meant applying for a building consent in much the same way as you would for a larger house.
Now there are two possible pathways:
Build using the new granny flat building consent exemption, if your project qualifies.
Apply for a building consent and follow the normal consenting process.
The exemption isn't compulsory. It's simply another option for eligible projects.
And that word eligible is important.
You can't simply decide you'd rather not get building consent.
The home and the building work have to meet the conditions of the exemption.
What granny flats can be built without building consent?
At its simplest, the exemption applies to qualifying homes that are:
new
standalone
single storey
no more than 70m²
self-contained
designed and constructed in accordance with the exemption requirements
compliant with the New Zealand Building Code.
The work also needs to be undertaken or supervised by appropriately licensed building professionals.
So we're talking about a proper little home built to proper standards.
Not popping a cabin in the backyard, connecting a garden hose and calling it a granny flat.
Does anything under 70m² automatically qualify?
No.
And this is probably the biggest misunderstanding we see.
70m² is a maximum size, not an automatic ticket to build without consent.
A 60m² home doesn't automatically qualify simply because it's under 70m².
There are detailed conditions around the building's design and construction, its foundations, structure, plumbing and drainage, fire safety and other aspects of the project.
Your site matters too.
That's why one of the first things we look at is not just what you want to build, but where you want to build it.
Do I still need to talk to the council?
Yes.
This is where the phrase “no consent required” can be a little misleading.
If you're using the granny flat exemption, you still need to apply to your local council for a Project Information Memorandum, usually called a PIM, and receive it before building work starts.
A PIM provides important information about your property and proposed project.
It can identify things you really do want to know about before somebody starts digging holes in the backyard, including information about the land, natural hazards and other requirements that may affect the project.
So although you're not applying for a building consent, the council isn't completely out of the picture.
What about the Building Code?
You still have to comply with it.
Completely.
The building consent exemption removes the requirement to obtain a building consent for a qualifying project. It does not exempt the home from the New Zealand Building Code.
That's an important distinction.
The home still needs to meet the required standards for things such as structure, durability, moisture, fire safety, access, services, energy efficiency and sanitation.
The exemption is about how the building work is authorised and managed.
It's not permission to build to a lower standard.
And nor should it be. Someone is going to live there.
Can my handy brother-in-law build it for me?
This isn't really the project for the “she'll be right” school of construction.
One of the safeguards built into the exemption is the requirement to use appropriately licensed professionals.
The design must be completed by suitably licensed or registered professionals, and the building work must be undertaken or supervised by licensed building professionals as required by the exemption.
That might sound slightly at odds with making granny flats easier to build, but it makes sense.
Under the exemption pathway, the council isn't approving the building through the usual building consent process or carrying out the usual consent inspections.
So professional accountability becomes particularly important.
Fewer council processes does not mean fewer building standards.
Will the council inspect my granny flat?
Not in the same way it would inspect building work under a building consent.
For work completed under the exemption, councils do not inspect and approve the construction as they would through the normal building consent pathway.
That's another reason choosing the right designer and builder matters.
You want people who understand the exemption, understand their responsibilities and are prepared to document the project properly.
Because when someone asks about that building in ten years' time, “Dave said it was fine” isn't terribly useful paperwork.
What happens when the granny flat is finished?
There's still a process.
Once the build is complete, documentation needs to be provided to the council so there is a proper record of the dwelling on the property file.
This can include final plans, Records of Work and relevant certificates of compliance.
That documentation matters.
If you sell the property in the future, refinance it or make an insurance claim, you want to be able to demonstrate that the granny flat was legally built and complied with the requirements that applied to it.
Paperwork may not be the exciting part of building a new home.
It's still rather nice to have when you need it.
What about planning rules?
This is another area where “no building consent” doesn't mean “build whatever you like, wherever you like.”
Building requirements and planning requirements are different things.
Your proposed granny flat still needs to comply with the planning rules that apply to the property, or you may need another approval.
There can also be site-specific issues such as natural hazards or other restrictions that need to be considered. MBIE's guidance specifically recommends checking that the site is free from unmitigated natural hazards and complies with local planning requirements before proceeding under the exemption.
That's why we'd be very wary of anyone looking at a floor plan and immediately telling you:
“Yep, you don't need consent.”
They haven't looked at your property yet.
What about water, wastewater and other services?
A granny flat is a home, so it needs all the usual services.
That can include:
drinking water
wastewater
stormwater
electricity
telecommunications.
Where those services are located and how the new dwelling will connect to them needs to be investigated.
Some associated building work or connections can have their own approval or authorisation requirements, even where the dwelling itself is being built under the granny flat exemption.
In other words, don't assume that because the house qualifies for the exemption, everything else happening on the property automatically does too.
Are there still council costs?
Potentially, yes.
Building without a building consent does not mean building without any council costs.
You'll need to allow for the PIM and there may be other council-related charges associated with your project.
You may also be required to pay a development contribution. MBIE specifically notes that a development contribution may be payable when applying for a granny flat PIM (not payable at the time but once construction is finished).
The actual costs will depend on your property, your project and your local council.
This is one of those areas where we think it's much better to find out early than discover it after you've already decided what to spend on the kitchen.
Is building without consent always the best option?
Not necessarily.
The exemption is a great development, and for the right home on the right property it can make the process simpler.
But there's still a standard building consent pathway available.
In some situations, obtaining a building consent may be necessary because the project doesn't meet the exemption requirements. In others, it may simply be the more appropriate pathway for the particular project.
The important thing isn't to start with:
“How do I avoid building consent?”
Start with:
“What's the right way to build this home on this property?”
Then work out which pathway fits.
A quick way to think about it
Here's the bit we'd like you to remember:
Up to 70m² = you MAY be able to build without building consent.
Not:
Up to 70m² = no consent, no council and no rules.
There is still a process.
There are still standards.
There are still qualified professionals involved.
And there are still things that need to be checked before you build.
Why we're actually pretty happy about that
We know rules and paperwork aren't particularly exciting.
But there's another side to this.
If you're building a granny flat for Mum, Dad, your adult children or someone else you care about, you want to know it's a safe, warm, durable home that's been built properly.
And if you're putting several hundred thousand dollars into your property, you want the building to be legal, properly documented and insurable.
The new exemption can remove some unnecessary process without removing those protections.
That's a good thing.
Don't let “consent free” become an expensive mistake
Our biggest piece of advice is simple:
Check first. Build second.
Don't buy a house design, sign a building contract or start preparing your section based purely on somebody telling you that granny flats under 70m² don't need consent.
That's only part of the story.
Make sure someone has looked at your property, considered the proposed home and worked through which requirements apply.
At NZ Granny Flats, that's part of helping you through the process.
We can look at what you're hoping to achieve, assess your site and help establish the right pathway for your project.
If the exemption applies, great.
If something needs further investigation, we'd rather tell you now.
Because finding out before you build is generally much cheaper than finding out afterwards.
Wondering whether you can build a granny flat on your property?
A good place to start is with the property itself.
Download our Granny Flat Site Assessment Checklist and take an initial look at the available space, access, services and other things that could affect your project.
Or tell us a little about your property and what you're hoping to build.
We'll help you understand what needs investigating and what the next step might be.
No jargon. No hard sell. And no pretending the rules don't exist just because they're inconvenient.