This article was prepared by Advance Build and is being published by the New Zealand Herald as advertorial.
As housing affordability pressures grow, more Kiwis are exploring solutions like granny flats. These minor dwellings are a clever way to add space and value to your home – and can create wonderful multigenerational living arrangements, too.
Curious about building one? Here are the answers to some of the most common questions
Do granny flats need council approval?
Yes.
You’ll need to connect to onsite services (eg sewer, plumbing, power), meaning you’ll require a building consent. You may also need a resource consent if your project falls outside your council’s district plan (eg in terms of site size, coverage or proximity to boundaries).
Each council has slightly different regulations, so it’s worth choosing a building company who has experience working with local councils. It’ll make your journey far easier!
How big can a granny flat be?
Again, this comes down to each council. If you happen to be in Whangārei, for example, you can go up to 90m². But generally speaking, you’re allowed to build a 60-65m² granny flat on your property.
The key is to choose a smart, space-efficient floor plan design that works for you. The Oasis 1 is a generously-sized 60m² 2-bedder with plenty of living space. Meanwhile, the compact Kemp 1 (47m²) is a 1-bedroom layout – perfect for properties with less space.

Can I rent out my granny flat?
Absolutely. In fact, the housing shortage is fueling an upsurge in demand for minor dwelling rentals across Auckland and Northland.
As a landlord, you’ll need to provide a formal rental agreement to your tenant. You’ll also need to ensure you provide your tenant with:
Separate access
Sufficient privacy
A dwelling that meets all Building Code and Healthy Homes standards.
Prefab vs traditional granny flats: which is better for me?
When it comes to constructing your granny flat, prefab is an easy, hassle-free option. It’s far quicker than a traditional build – and less stressful, too. You’ll know exactly what your costs are from the outset and, because much of the build happens inside a factory, your project won’t be derailed by bad weather or other onsite delays. You’ll also experience far less disruption on your property.

Does a granny flat add value to a property?
Definitely. A well-designed minor dwelling will boost your property’s appeal and resale value. Granny flats give you a versatile space for ageing parents, adult children or house guests and, if you decide to rent it out, provide another source of income.
People are increasingly looking for homes that provide financial flexibility (like rental income) or multigenerational living. A granny flat is a smart way to meet those needs and give you excellent long-term ROI.
Ready to grow your property’s value?
Unlock space and rental income with a granny flat from upper North Island prefab specialist, Advance Build. You can choose from a wide range of floorplans – all built offsite for speed and quality.
Request a custom quote from the experienced Advance Build team today or visit advancebuild.co.nz for more information.