If you have an attached garage but it has become more of a storage area than a space to keep the car away from the elements, consider converting it into a liveable room.

Of course, this option is not suitable for each and every property. But if you have a spacious driveway or some extra room on the side of the house, this could be a good one for you.

After all, conversion is a great way to utilise the space that otherwise is wasted. Adding an extra room can also improve your home’s appeal (we live in a world where new builds commonly have bonus rooms) and will most certainly increase its resale value.

And the best part is: because a garage already has a foundation, walls and a roof, it will cost you just around half of what you’d be spending for an all-new addition.

Where to begin?

First of all, you need to decide on the purpose of the new room. Is it going to be a bedroom, an office or maybe a game room?

Then, map out a plan of what you would like the garage to look like once conversion has been complete. Will you need a new door, and if so, where will it be placed? Will any extra windows be added? What type of lighting will you need? Are you planning to add a bathroom?

By asking these questions before the project begins, you can save time and money further down the track.

Get your plan approved.

Under the Building Code of Australia (BCA), a garage is considered a non-habitable structure. Therefore, once you have decided what your new room is going to be, you will need to submit a Development Application to your local Council and get it approved prior to commencing any work.

Although it may be tempting to do conversion on the sly, it is much better to do it legally so there will be no hassle if the house is ever sold.

Things to consider.


Ceiling heights is a key factor in meeting the Australian Standards for a habitable room. It must be at least 2.4 meters. At the same time, the minimum ceiling heights for a garage is just 2.1 meters. If you found yourself in a situation where the ceiling in your garage is lower than 2.4 meters, raising the roof will most likely be your only viable option as removing the concrete slab of a garage floor can be both costly and difficult to do.


Garage walls are normally single brick and will need to be sealed with a waterproof membrane or waterproof paint to prevent rising damp. Garages also do not have the same insulation as the rest of your home, so you will need to correctly insulate the room to make sure that the tenant doesn’t fry or freeze (we all know how crazy Australian weather can be).

Adding a stud wall can be a great solution for housing your insulation (as well as any electrics). This can then be finished with a plasterboard and paint or wallpaper.


To be classified as a habitable space, the concrete slab has to comply with the BCA Standards. This means that the entire area beneath the concrete slab must be treated with a termite management system. You will need to check the requirements of your State as variations apply to the National BCA termite risk management provisions.

Since garage floors are not elevated, you will have to make sure that moisture can’t enter the room. If there is no evidence of a waterproof membrane beneath the slab, you will need to sort this out. There are many commercial products available for this purpose and they can be rolled or brushed on. Any rainwater will need to be diverted from the habitable space as well.

There is a chance you may need to elevate the floor altogether to allow for insulation over the concrete slab and prevention of water penetration, so having it checked by an expert in the beginning is a good idea.


Your new room must have windows to meet the requirements of the BCA. Specifically, the room must have a window opening that has an area equivalent to 10% of the floor area. If there are no windows in your garage, replacing the existing garage door with a large window is a viable option.

Thermal Comfort

As part of your renovation, you will need to provide heating and cooling for the space. This can be done either by tying into the house’s main system or adding an independent one.

You will also need to ensure compliance with either The Building Sustainability Index (BASIX) in NSW or the Nationwide House Energy Rating System (NatHERS) in all other states. These systems are designed to determine a buildings thermal comfort and the need to heat or cool the building to keep the occupants comfortable.

Details of compliance will need to be submitted as part of your Development Application.

Electrical Works

Adequate lighting will need to be installed. If you are intending to use the new room as a bedroom, a smoke detector will also need to be installed. Consider installation of additional power points if required.

An electrical service upgrade may be required to accommodate the larger load.

All electrical work must be carried out by a licensed electrician. They can provide you with all necessary Certificates of Compliance.

Bathroom Addition

If you are planning on adding a bathroom as part of your conversion, make sure to address it as early in the project as possible as this is usually the hardest part.

You will need to engage a licensed plumber to install the plumbing system for you and provide necessary Compliance documentation.


It is a requirement of some States, that an additional on-site parking spot must be available to replace the garage parking.

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Best Regards,
The EYEON Property Inspections Team

At EYEON Property Inspections, we help you buy and sell with more confidence.