Advice On Garage Conversion Into A Habitable Room (NZ)



If you want to expand the living space in your Auckland home but don’t have the space or budget for an extension, converting your garage could be the perfect solution.

Because the basic structure is already in place, garage conversions are frequently less expensive than home extensions.

The team at Style Plus Renovations have put together this article to answer a few questions, and to provide some advice to those exploring the idea of converting your garage to a habitable space.


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The best place to start with a garage conversion is to be clear about your goal for the renovation. What would you like the space to be when the work is completed?

In the current climate moving house may not be an option for a variety of reasons. For example, you love your location, you love your home, and buying a new home is currently prohibitively expensive.

You probably thought long and hard about buying the house when you bought it, but now you need more space for your growing family or perhaps as you now work from home, a space for a home office.

So naturally, extending your home or converting a space comes to mind.

Using your garage (internal garage or external garage) and converting it into a livable space is one of the more popular options as you are not altering the footprint of the house. But, there are a few things to consider as it’s not a simple and easy decision to make.

There is a number of ideas to use the garage space. Here are a few ideas to convert your garage into the following areas:

  • A guest bedroom
  • A second living room
  • A home office
  • A home gym
  • A rumpus room for kids
  • A games room
  • A home theatre
  • A granny flat


Before we delve into the specifics of garage conversions, there is one question that comes up during our meetings with clients. What constitutes a “change of use” when I change my garage to a habitable space? The answer is that it depends on whether the change to the space is in the same ‘use’ category. This may be confusing, so the following three examples will help you with the term ‘change of use’:


Building (Specified Systems, Change the Use, and Earthquake-prone Buildings) Regulations 2005.

Schedule 2 (Uses of all or parts of buildings).

The following examples provide some clarity.

For example (1);

A garage space not connected to a house is being made into a sleepout for a family member. This change is not a change of use as both old and new uses are within the same category of “sleeping single home”.

For example (2);

A householder plans to launch a business as a sole trader and will use their garage as their office/workspace. This is not a change of use because the main use of the building still sits within the “sleeping single home” category.

For example (3);

A homeowner that has a large single house, would like to convert it into two dwelling units (section 115(b) of the Building Act will apply). This is a category change, from the “sleeping single home” to “sleeping residential” category. This is a change of use because there are stricter Building Code requirements in the new use.


Building Act 2004

Section 115 (Code compliance requirements: change of use)

Definition of Sleeping Single Home. Detached dwellings where people live as a single household or family, including attached self-contained spaces such as granny flats when occupied by a member of the same family, and garages (whether detached or part of the same building) if primarily for storage of the occupants’ vehicles, tools, and garden tools.

Definition of Sleeping Residential. Attached and multi-unit residential dwellings, including household units attached to spaces or dwellings with the same or other uses, such as caretakers’ flats, and residential accommodation above a shop.


The conversion of a non-habitable space to a habitable space is not considered a “change of use” under the Building Act as long as the building remains a “single household unit” after the renovation work is finished.

A garage has a classification of Class 7.0 (Outbuildings) which is considered a non-habitable structure.

Converting the garage into a habitable space would be a reclassification to Class 2.0 (Housing).

For example (1);

converting a garage space (non-habitable space) into a bedroom, media room or home office is not defined as a “change of use” under the Building Act.

This is due to the fact that the original use of a non-habitable building on a residentially zoned property is a single household unit’, and it remains a single household unit after the alterations are completed.

It is often the case that a non-habitable space was built to different requirements compared to the rest of the house and some building work is required to bring it up to the NZ Building Code for habitable spaces. 

It is recommended that you consult with an architect to carry out a feasibility study which will determine whether it’s even possible to utilise the garage space.

At Style Plus Renovations, we provide a free feasibility report service.


Building Regulations 1992, Schedule 1, The building code, Clause A1—Classified Uses.


There are basically two types of garage conversions. 

  • Creating additional space.
  • Creating a self-contained living space.

Creating additional space –  This is the easiest conversion where the non-habitable is converted to a habitable space which adds space to the existing home. For example, turning the space into an extra bedroom or living area. Adding a bathroom is allowed, however, it must meet the rules. 

Creating additional space work will require building consent and once the work is completed to the required standard, the council will issue a Code Compliance Certificate (CCC).

Creating a self-contained living space – To start with, self-contained living space is typically located on the same property as a larger house. They are also known as a second household unit, a secondary dwelling, or minor dwelling.

If your goal is to convert the garage space to a self-contained living space, within the same detached house, and the space is intended to be used by members of the same family or household, then, this situation relates to the definition of Household unit in the A2 clause of the regulations and clause A1 2.0.2 detached dwellings of the building regulations.

It basically remains a single household with self-contained spaces but there is no change of use and is not intended to be a multi-dwelling.

A garage conversion within the boundaries of the existing house may be cheaper, but it will need to meet regulations for health and safety with things such as firewalls, sound separation, secure locks, safe exits in case of fire, and so on.

Even if your plans are for your self-contained living space to be used by your family, you still need to think about whether you want to share spaces such as gardens, decks, patios, front paths, driveways, bin storage and power/water meters. 

The conversion will require building consent and resource consent. And once the work is completed to the required standard, and council inspections are passed, the council will issue a Code Compliance Certificate (CCC).

If you want your new space to generate rental income, the Tenancy Act regulations kick in for security, health, heating and parking requirements.


(1) Building Regulations 1992, Schedule 1, The building code, Clause A2—Classified Uses.

(2) Building Regulations 1992, Schedule 1, The building code, Clause A1—Classified Uses.

If you live in or near Auckland, it is advisable to determine your residential zone, as well as the rules governing how land in that zone can be used. Also, how many dwellings can be built on the same site.

You can find your zone by looking up your address on the Auckland Unitary Plan here


Auckland Unitary Plan zones regarding building and minor dwelling:

  • Single House Zone
  • Mixed Housing Suburban Zone
  • Mixed House Urban Zone

In the two mixed house zones, two properties can be built on the section. In the Single House Zone, a minor dwelling can be added. However, it must not exceed a floor area of 65m2 excluding decks and garages.

You will also need to check that your minor dwelling plans meet the criteria for your zone.


If a garage is converted into a living space without the necessary consents and certifications, future owners of the property may have difficulty insuring the home. One way to check if the conversion has consent is to check the council property file

You can apply for a Certificate of Acceptance (CoA) only if building work was constructed without building consent from 1 July 1992 onwards. It is recommended that you attend a council CoA pre-application meeting before applying for a CoA.


  • What are the top 4 garage conversion ideas?
    1. Home Office
    2. Spare Bedroom
    3. An Income Opportunity
    4. Entertainment Room
  • What is the cost to convert a garage space to living space NZ?
    The typical costs for transforming a garage into a room are upwards from $1,800/m2. Please note that these figures do not include architect fees, building consent fees, resource consent fees, excavation costs, and engineer fees, these are all additional costs.
  • How long does a garage conversion take?
    Typically, the timeline for this project spans approximately 4 to 6 weeks, depending on your garage's existing state and the scope of work to be completed. Your renovation team will undertake several tasks, such as:
    1. Insulating the walls and ceiling.
    2. Elevating the floor to accommodate insulation above the concrete base.
    3. Substituting the garage door with a window and/or a door.
    4. Enhancing the electrical system to support additional appliances, which includes adding more power outlets.
    5. Establishing effective heating and cooling systems.
    6. Demolishing walls to create an open-concept space or introducing an internal door as needed.
  • What do I do if I find some rot in the framing when the cladding is removed during my garage conversion?
    For older houses, if the cladding is removed it might reveal rot in the structural elements underneath. This will require remedial work and building consent.
  • What do I need to do if I have unlined block walls in my garage?
    If your garage has block walls. It is unlikely to meet the minimum requirements for a habitable room. The walls will need to be sealed and finished with appropriate wall linings.
  • What ceiling height do I need for my garage conversion?
    Check your garage's ceiling height; it must be at least 2.1m from the finished floor to the finished ceiling in order to be converted into a habitable space.
  • How long is cladding and joinery supposed to last?
    Building materials such as cladding and joinery/windows are only required to last for 15 years, durability. If it is older than 15 years, it will need to be upgraded.

If you’re still undecided about what to do with the unused garage space, make sure to consult with professionals (architects, builders/project managers, and financial advisors) to get different perspectives on the situation so you can make an informed decision that will benefit you in the long run.

Alternatively, contact us to discuss your garage conversion and arrange for a free architect’s feasibility report.

If you are still looking for more inspiration, check out our renovation articles on our Blog.

Whilst all information is considered to be true and correct at the date of publication, changes in circumstances after the time of publication may impact the accuracy of the information.

The information may change without notice and Style Plus Renovations is not in any way liable for the accuracy of any information printed and stored or in any way interpreted and used by a user.


As an Auckland North Shore family-owned and run business, Style Plus Renovations cares about what we do and we take the time to fully understand your renovation needs. We are also proud to receive some exceptional compliments from our Auckland clients.

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