Dividing a house to provide an additional dwelling
Case study features
● Creating an additional dwelling, extending off existing home
● Repurposing a 3-bedroom family home when needing to downsize
● Working with a very tight budget
● Working with local village networks
Dwelling and property description
Our owner welcomed their first tenant into their home in early 2026 following the creation of a flat within the existing footprint of their home, over the last 1-2 years.
A standard three bedroom Paekākāriki home had an extra main bedroom and bathroom added over 20 years ago off the living area as an extension.
This has enabled the dividing off the other end of the house as a separate flat as it contains a bathroom and two bedrooms. This raises the option for those wanting an additional dwelling to consider in their design whether their interest might enable the addition of a new bathroom and bedroom for themselves at the same time!
In the flat the bathroom and larger bedroom remain unchanged, while the smaller bedroom on the corner of the house provides a french door entrance to the flat with a small deck -the french doors have replaced a window. That smaller room’s wardrobe is now a pantry and the other side of the room is
filled by a custom-made kitchen bench (Bunnings) and a double sink (put in by a plumber with piping) on top of a kitchen unit with a small fridge. The owner
ensured the bench ran the whole length of the room as she felt it would make the room feel bigger.
Above it is an original high small window and other cupboards, and some attractive tiling runs around the bench. In total it's a very economic use of the space.
An electrician put in an extractor fan and extra power points above the bench. There is no oven but a good sized bench top for a double element and a toaster oven. Council confirmed this was not classified as a kitchen. An additional door has been added in the hallway dividing the two dwellings.
Care of the large productive garden is shared by the tenant and owner.
Process
The first step in the creation of the flat started 18 months to two years before its completion: the movement of the washing machine into the garage as a shared space. This required new plumbing and pipes but it was ideal as it was in line with the pipework to the existing kitchen.
As part of the design process the owner got friends over and asked them what they would want if they were renting it. This led to a light in the hallway she hadn’t thought of.
A second separate step was the installation at the french window. The wall featuring the kitchenette had to be redone with new gib, insulation and bracing on council instruction. Then there was further drainage for the sink and wiring for the electrics. Finally the dividing wall was installed in the corridor with some repainting.
With the design of the home the owner had the option of making the flat two bedrooms with the flat having the existing front door.
The owner would have in this case retained an entrance off the living area and closed off the existing door between the living area and hallway.
Another option would have been to put a new door through to the second bedroom so the tenant had the main doorway. In the end they decided it was more important to keep the second bedroom for their children and guests.
Image: Kitchen floorplan with small bench.
Budget and personnel
Everything but the kitchen bench (which has been custom made by Bunnings to fit the room measurements for $600) was found in Paekākāriki second hand, even the fridge.
The wooden kitchen cabinets were bought through Facebook group ‘Paekākāriki Tauhokohoko’ for $100 (they were on their way otherwise to the tip) and then stored till they could be used in the garage.
The tiles are expensive artisan tiles that had been left over from a job. The sink and fridge (“It was on the side of the road! My daughter came home one day saying "I’ve got you a fridge!”) were free.
Building personnel
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Building and tiling | Josh Begg (son of local resident Sharon Wilmshurst)
“an amazing carpenter, I highly recommend him”
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Repainting of the new kitchenette | Nik Bullard
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Laundry plumbing | Andy from Elemental Plumbing
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Remaining plumbing | Pete the Plumber
* building consent application not included.
House history
When our owner bought it with their husband in 2008 they had three children. Moving back after having the house rented for some years the owner needed additional income from rent, but also liked the idea of sharing the garden and property with someone else living separately.
“The hardest thing was when we wanted to move back and the family who were living here couldn't find a place to rent in Paekākāriki. Uprooting someone's life because we wanted our house back. And they were paying our mortgage. It's very uncomfortable and confronting.”
Reasons
“It was a case of ‘how on earth am I going to keep the house’. It was financial but it’s not just financial because this property is really big. There’s so much garden! I really wanted someone who was interested in gardening because I’m really interested in learning how to grow our own food. I wanted someone I could work with. Who could contribute to harvesting. So we share the laundry and we share the garden and all the produce.”
“There’s not just a financial burden, carrying the burden of looking after an entire house and a garden is really big. And then the wellbeing of the tenant is another job.”
There’s no fence between the two spaces in terms of garden but there could be if it was wanted or needed.
“Every time I came to this house to do something I thought ‘I want to live here again’. So, even though I couldn't afford to be here it felt like the time. Sometimes you have to put a line in the ground. That the act of faith of moving back in, something would eventuate.”
“That was 2021 and I could see that soon I would have to start paying the whole mortgage myself. My adult son was there then paying board. And then I noticed that that part of the house was lending itself to being separate. Also, because when I moved back in here - when I closed the doors (between the living room and rest of the house) I realised I didn’t need anything else. I had my kitchen, bedroom and bathroom.”
The Council permit experience
The owner talked to the council who advised on the process and on not classing it as a kitchen (“rather than a kitchen you are putting in a kitchen bench”). The owner then, as instructed, uploaded images of the work and other documents in progress done to the Simpli site. But they didn't hear from the council and that was taking so long and the owner really needed a tenant. About three months later they told the owner they hadn't noticed they had uploaded the material. Apparently the owner should have sent them an email telling them they’d uploaded it. They then advised the owner that the application was closed because they clearly had finished the building work and that now they had to do it retrospectively.
“It was just way too hard… the process. I had to visit the webpage quite a few times to get my head around it. It took a lot to work through all their criteria and caveats. And then to have to go to the building code and work out which building code applied. I’m not a builder. And then I had to go to the Resource Management Act and looked up all these things. And then it repeats all the same information and sends you to same page, and then I go back and then I’ve lost track of what I was starting to look for… “
“It seems like everything is OK but the process.. It's just too hard. It felt combative even when I was talking to council. Like I had to be really aggressive about it to find the information I wanted. Which is not how I like to be.”
“You can be so scared about being penalised, she says, for doing something wrong rather than feeling enabled.”
“There’s an emotional toll. It's why people have project managers. It’s your home and all that represents. It’s often unspoken. You’re literally cutting into your home and everything that represents. Psychologically it’s quite a big thing. I think people need to take that into account.”
“It was certainly not something I could rush. Apart from the design and planning and choices there’s a whole other part that takes time to sit with when you’re changing something. It needs to be factored in because it's not easy work.”
Tenant or flat mate?
The owner had to decide if this was a tenancy or a shared flat. If the owner is living in the house, the tenant or flat mate is not covered by the residential tenancies act, which also means things like Healthy Homes don’t apply.
“But I think the healthy homes provisions are really important. They’re basic and not that hard. It's respectful. It benefits the house and the tenant, it’s a win win.”
This included providing heating, having underfloor and ceiling insulation and ensuring a vent in the kitchen area. They had done some of this when they rented the house out a few years ago.
The IRD webpage determined that as the owner was living in the house the rental would not be treated as taxable income.
The owner still felt having an agreement was important, despite that not being needed. “There’s a power imbalance when an owner is living with a flatmate. I wanted to be careful about that.”
So the owner took the provisions from the standard tenancy agreement into theirs, even though it's not a tenancy agreement by law.
“This tenant is not covered by the residential tenancies act, so doesn’t have redress to the tenancy tribunal. Which isn’t great, but that’s the law.”
In determining the rent they looked around at what others were paying and what they needed to cover the mortgage. They went for the middle of the range with the determination if possible not to raise it. At the time of writing May 2026 it's $330 which includes the internet. They pay 50/50 on power. The owner knows of another equivalent flat which is $460, but feels $320 is expensive enough.
In New Zealand, the general guideline is to spend no more than 30% of your gross income on rent.
Part of the rent is to help in the garden - this is put in the agreement as a minimum one hour a week.