garage conversion cost calculator

Garage Conversion Cost Calculator Tool (NZ)

Converting a garage into a dwelling or granny flat is a fantastic way to create additional living space on your property. This transformation breathes new life into your underutilized garage, providing a space for family members, guests, or even rental income. Beyond the added space, a conversion can improve the overall look of your home and potentially increase its value.

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Thinking of converting your garage into a livable space? A garage conversion can be a great way to add extra square footage to your home without the hassle and expense of a major addition. But before you get started, it’s important to factor in the costs involved.

Our garage conversion cost calculator can help you get a rough estimate of how much your project will cost. Just enter a few details about your project, such as the size of your garage and the type of conversion you’re planning, and our calculator will provide you with an instant estimate.

What is a Garage Conversion?

A garage conversion is the process of converting a garage into a habitable room. Garage conversions can be used to create a variety of different spaces, such as bedrooms, bathrooms, home offices, or even granny flats.

Why Consider a Garage Conversion?

There are many reasons why you might consider a garage conversion. Some of the most common reasons include:

  • Need more space: A garage conversion is a great way to add extra square footage to your home without the need for a major addition.
  • Increase your home’s value: A garage conversion can add significant value to your home.
  • Create a more functional space: If you’re not using your garage for its intended purpose, a conversion can help you create a more functional space for your needs.

Factors Affecting the Cost of a Garage Conversion

The cost of a garage conversion can vary depending on a number of factors, such as:

  • The size of your garage: Larger garages will obviously cost more to convert than smaller garages.
  • The type of conversion you’re planning: A simple conversion, such as a bedroom, will typically cost less than a more complex conversion, such as a bathroom or kitchen.
  • The materials you choose: The materials you use for your conversion will also affect the cost. For example, using high-end finishes will cost more than using more basic materials.
  • The complexity of the project: Some garage conversions will be more complex than others. For example, if your garage has a slab foundation, you will need to add a new foundation for your conversion. This will add to the cost of the project.

Garage conversion cost in New Zealand

The cost of converting a garage in New Zealand can vary depending on several factors, including the size and complexity of the conversion, the materials used, and the location. However, as a rough guide, you can expect to spend anywhere from $40,000 upwards for a basic conversion. For more elaborate conversions, especially those that require plumbing, electrical work, and high-end finishes, the cost can go over $150,000.

Here’s a table outlining the typical garage conversion cost range for different conversion types in Auckland:

Conversion type Typical cost range
Basic room (no plumbing) $60,000 – $80,000
Adding a bathroom $90,000 – $110,000
Full granny flat (bathroom + kitchen) $110,000 – $150,000+

Note: Not including architectural fees,  council fees, engineer fees, foundation work if required) and excavation/drainage work (if required)


Here are some tips for keeping the cost of your garage conversion down:

  • Get multiple quotes from qualified builders before making a decision.
  • Choose simple and affordable materials.
  • Do some of the work yourself (if you have the skills and experience).
  • Be realistic about your budget and don’t overspend.

Checklist for garage conversion eligibility

Before you start planning your garage conversion, it’s important to check if your garage is eligible for conversion. Here’s a checklist to help you get started:

  • The garage must be structurally sound. This means that the walls, roof, and foundation must be in good condition and able to support the weight of a habitable room.
  • The garage must have a ceiling height of at least 2.4 meters. This is the minimum ceiling height required for habitable rooms in New Zealand.
  • The garage must have adequate natural light and ventilation. This can be achieved by installing windows and/or an air ventilation system.
  • The garage must be weatherproof. This means that the roof, walls, and doors must be in good condition and able to keep out the elements.
  • You may need to obtain building consent from your local council. This will depend on the complexity of the conversion.

It’s important to consult with a qualified builder or building surveyor to determine if your garage is eligible for conversion and to get advice on the best way to proceed.

Our Garage Conversion Cost Calculator

Our garage conversion cost calculator can help you get a rough estimate of how much your project will cost. Just enter a few details about your project, such as:

  • The size of your garage
  • The type of garage you have
  • The standard of materials you plan to use
  • Does it include kitchenette/bathroom?
  • Include other fees associated with the conversion?

Once you’ve entered this information, our calculator will provide you with an instant estimate of the cost of your garage conversion.

It’s important to note that our garage conversion cost calculator is just a starting point. The actual cost of your project may vary depending on the specific factors mentioned above.

For more detailed information on the building consent process and requirements for recladding, you can visit the Building Performance website or the Auckland Council website.


Every house is unique, and so are garage conversions. That’s why it’s important to get a tailored quote for your specific project. There are many factors to consider, such as the design of your existing garage, the materials used and those you want to replace them with, the condition of your home, existing drainage, existing foundation and whether any structural repairs are needed. This cost calculator doesn’t include these variables. Also, in some cases, you might need an engineer. The scope of the project and how easy it is to access the site can also significantly impact costs. So, make sure to get a detailed and personalized quote for your recladding project.

Garage Conversion Cost Calculator Tool (NZ)

To get a rough estimate of your garage conversion costs, you can use our garage conversion cost calculator tool below – but keeping in mind that this is only to generate an estimate, there is many other factors that come into play and makes every garage conversion project differant, so if you require a quote for budget purposes, we recommend arranging an on-site visit for a comprehensive quote.

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    Please note: 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 on the accuracy of the information. The information may change without notice and Superior 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.