Bathroom Standards in Australia: Waterproofing and Size Tips for a Seamless Home Renovation

Taking on a bathroom renovation in Australia can be an exciting venture. However, it comes with its unique set of challenges and standards that need to be considered. One such critical aspect is understanding the standards surrounding waterproofing and size specifications specifically the bathroom standards in Australia. These factors are not only vital for creating a functional and aesthetically pleasing bathroom but are also mandated by the Australian Standards (AS 3740-2010) for Waterproofing of Domestic Wet Areas. 

In this guide, we will delve into these key considerations, providing practical advice for homeowners, builders, and designers. Our goal is to help you navigate the complexities of bathroom renovation in Australia, ensuring your project meets both regulatory requirements and your personal expectations. From understanding waterproofing essentials to considering the optimal bathroom size for your needs, this comprehensive guide is your one-stop resource for a seamless home renovation project.

The Standard Bathroom Size in Australia

According to the Australian Building Codes Board (ABCB), the smallest size for a bathroom is 1.4m x 0.9m, or 1.2m x 1.2m, depending on your floor plan. Of course, this small bathroom only includes a basin and a toilet and does not have a lot of space for much else. 

While this is the smallest bathroom size for an average Australian home, bathrooms that include shower, cabinetry, vanity, toilet, and towel rails are standard. To include these, your bathroom should be at least 3m x 2m big. Slightly bigger bathrooms can be as big as 3.5m x 2.5m, with even bigger bathrooms being 4m x 5m. 

Of course, when renovating your bathroom, you will have to look into the size of the individual amenities you will add some of these include:

Shower & Bath

The minimum size of a walk-in or enclosed shower can be as much as 900mm x 900mm. If you decide to have a bathtub, remember that the standard bathtub size is 1800mm x 700mm. 

Toilet

A 1600mm x 900mm clearance is the average size for a toilet pan as it does not take up too much space and allows easier movement around the toilet pan. However, you could choose a larger toilet depending on your bathroom layout, and don’t forget to provide a toilet roll holder within reach to the toilet. 

Vanity / Hand Basin

The average vanity or hand basin in Victoria is approximately 0.8m above the floor, with a depth between 0.32m and 0.5m if it is semi-recessed. However, the height for the hand basin can be increased depending on your needs.

Door & Circulation

The average door size in Victoria is 820mm in width and 2040mm in height. Therefore, the bathroom standards for door swing should be free from obstructions.

Towel Rails

You should install a towel rail approximately 900mm off the floor, making it easily accessible for people of all heights.

How to Calculate Bathroom Floor Space

The first step to properly renovating your bathroom is to calculate the minimum bathroom size in Australia. Whether it’s new bathrooms or bathroom renovations, calculating the floor space also helps you decide the space for each fixture, such as the shower cubicle and the toilet. Once you consider these minimum requirements for the bathroom standards, you can design a bathroom that will last for years. 

It’s easy to calculate the floor space of square or rectangular bathrooms since all you need is measuring tape. Place the measuring tape on one end of a wall, and measure it until the end of the wall. Then, repeat this step for the adjacent wall (the wall right next to the one you just measured). These values are the length and width of your bathroom. You can get the total floor space of your bathroom by multiplying these values. You can then compare it to the standard bathroom size in Australia.

Waterproofing Bathroom according to Australian Standards

Along with ensuring that your bathroom design looks brand new, you must also meet the necessary bathroom standards in Australia for waterproofing. After all, designing the perfect bathroom is not just about getting some pretty tiles so that it looks new.You also need to make sure it functions and lasts as a new bathroom as well. 

You must ensure that the bathroom complies with National Construction Code (NCC) of Australia and Australian Standard’s AS3740-2010 waterproofing guidelines. Some of the important things you must consider include waterproofing the wall behind a wet fitting up to a minimum of 150mm above the fitting . 

Of course, the standards can shift slightly if you have a wet room bathroom, meaning there is no shower screen separating the different parts of the bathroom. Since this bathroom is likely to have more wet areas, the wall and floor of the bathroom should be waterproofed up to at least 1800mm. 

You can build your dream bathroom according to Australian waterproofing standards for the floor and walls. But for that, you need to call in an experienced waterproofer or tiler. The requirements for 150mm waterproofing applies to all other wet rooms in your home, including the laundry and the ones with a timber floor.

The Cost of Bathroom Waterproofing

The cost of full floor waterproofing can depend on various factors, like where you’re located in Australia and the general size of the bathroom. It’s highly recommended that a compliant waterproof membrane be installed under the bathroom floor to prevent water penetration that could cause damage to the building or cause unhealthy and dangerous conditions for the occupants. 

The average price of waterproofing is about $40 per metre square. Therefore, you can expect to pay between $500 and $1000 for a standard-sized bathroom. With a qualified tiler or waterproofer, you don’t have to worry about how the waterproofing looks or if it meets Australian standards for waterproofing. The waterproofing product should last at least 10 years from the date of installation and the installer should provide you with a final compliant certificate and a product warranty certificate at the end of the job.

Other Bathroom Standards in Australia

Besides waterproofing regulations in Australia, you’ll need to follow other standards as well. These can include ventilation standards for your bathroom as well as other important considerations.

Ventilation Standards

According to the ABCB, each room needs a window at least 10% of the total floor plan. But if you do not want a window in your bathroom, you will need to install an exhaust fan to allow air circulation. 

For effective cross ventilation in a bathroom, an exhaust fan with an output of at least 25l/s is necessary according to the ABCB, and vent cover is recommended for energy saving.

Installing an exhaust fan can also help eliminate moisture and prevent subsequent mould growth, which can be dangerous for your health.

Door Circulation Standards

According to the NCC, the minimum clear pathway for any door in a house is 850mm. Remember, 850mm is the total, unobstructed clearing space. Therefore, it cannot include door handles, stoppers, or even other doors.

In the case of a double door, 850mm should be the minimum width of a single door opening. For a sliding door, the unobstructed space should be according to the NCC recommendations when it has been fully extended.

Plumbing Regulations 2018 (Amendment 2022)

Recently, Plumbing Regulations 2018 underwent certain changes. You will now have to consider these when looking to renovate your bathroom and meet the necessary bathroom standards in Australia. 

One of the biggest changes is that a restricted electrical worker’s license is no longer a prerequisite to become qualified in Type A appliance servicing work. This makes it a little more convenient to find the right professional for your renovation. 

In Victoria, it is compulsory that the plumber is required to lodge a plumbing compliance certificate with the Victoria Building Authority (VBA) within five days of completing the works. It is important that you keep a copy of the compliant certificate to ensure you are protected and compensated if any workmanship associated defects arise within the first 6 years of completion.

Building Act 1993

You should also make sure that any additions you make are in accordance with the Building Act of 1993. According to the Building Act of 1993, all changes to a property must first be accredited by the Building Regulations Advisory Committee. 

Furthermore, places of exit must always be easy to access, well maintained, and unobstructed in the event of an emergency.

Gas Works (in Victoria)

In Victoria, if you have a gas appliance in the bathroom that connects to the gas line it could be classified as a complex gas installation and it is compulsory that you lodge the project with Energy Safe Victoria (ESV) at the beginning of project and arrange for independent gas safety inspection and obtain a gas compliance notice from ESV.

FAQ

Can I Waterproof My Own Bathroom?

You could waterproof your bathroom, but that could end up being more expensive in the long run if you run into trouble. You have the added benefit of home warranty insurance when working with professionals, specifically if the required renovations exceed $3,300. 

Do I Need A Plumber To Replace My Sanitary Fittings? Can I Do It Myself?

Licensed plumbers have both the right tools and the necessary experience to properly replace all your sanitary fittings. Not only do you risk hurting yourself or damaging your home, you also risk voiding your home warranty insurance. Since you are not an authorized plumber, you should talk to one that your insurance provider approves of.

What Is The Standard Bathroom Door Width In Australia?

All doors in a house should have an unobstructed clearing of at least 850mm according to the NCC, which also includes bathroom doors. The clearing should be clear of door handles, stopper, and any other obstructions.

What certificates or paperworks do I need at the end of a bathroom project?

• Plumbing Compliance Certificate 
• Waterproofing Final Inspection Report and Certificate of Compliance
• Waterproofing Product Warranty Certificate
• Product Warranty Certificate and Manuals for all Sanitary fixtures and Fittings (Remember to register the products to activate the product warranty period.) 

It is also a good idea to keep the receipts and product codes (with date of purchase) for faulty product claims.

If the bathroom project involves structural works and is managed by a builder or head contractor, please ensure you get hold of the builder’s domestic insurance, the building’s final certificate or occupancy permit and keep all personnel’s contact details for repair of defects during the defects liability period. (Generally 12 months from the date of completion.)

What’s Next

Understanding and adhering to bathroom standards in Australia for waterproofing and size is crucial for a seamless home renovation. By following these guidelines, you can create a functional and compliant bathroom that meets the needs of your household. 

If you have any further questions or require expert assistance with your renovation project, don’t hesitate to contact SQM Architects. Our experienced team is here to help you bring your dream bathroom to life.