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Understanding Australian Plumbing Codes

Layla Sawyer -

Understanding Australian Plumbing Codes

If you’re DIYing your home, it’s important to buy tapware and fixtures that are up to standard. Plumbing codes exist to make sure your home project is safe, efficient and sustainable. Here, we break down the Australian plumbing codes you need to know.

The Plumbing Code of Australia (PCA)

The PCA is part of the National Construction Code (NCC) and sets the minimum requirements for plumbing and drainage work. It's updated every three years, with the latest version released in 2022.

Key plumbing codes for DIYers

Water supply

When choosing taps or shower heads, check their pressure requirements. 

The codes outline the requirements for water pressure, pipe sizes and materials. This ensures that when you turn on your tap, you get a consistent and safe flow of water.

  • AS/NZS 3500.1: This standard covers water services, including pipe sizing, materials and installation methods.
    • Minimum water pressure: 50 kPa at outlets
    • Maximum water pressure: 500 kPa for residential properties

Sanitary plumbing and drainage

If you're moving a toilet or adding a new bathroom, getting your gradients right will help you avoid drainage issues.

The codes outline correct pipe gradients and connections to make sure wastewater flows away from your home.

  • AS/NZS 3500.2: Outlines requirements for sanitary plumbing and drainage systems.
    • Minimum pipe gradients: 1:60 for 100mm pipes, 1:80 for 150mm pipes.
    • Inspection openings must be provided at changes of direction and at intervals not exceeding 30 meters.

Hot water systems

When installing a new hot water system, you'll need a tempering valve to meet the delivery temperature requirement for bathrooms.

The codes set standards for temperature control to prevent scalding and ensure energy efficiency.

  • AS/NZS 3500.4: Specifies requirements for hot water systems.
    • Temperature requirements: Minimum 60°C for stored hot water, maximum 50°C for delivered hot water at residential addresses.

Do not attempt to modify your hot water system without a plumber — checking your system and choosing parts is fine, but working on hot water systems without a plumber is technically illegal in Australia.

Water efficiency

When selecting new fixtures, check the WELS rating. Higher star ratings mean greater water efficiency.

The Water Efficiency Labelling and Standards (WELS) scheme mandates water efficiency ratings for fixtures:

  • Taps: Minimum 4-star rating (6.0 L/min)
  • Showerheads: Minimum 3-star rating (9.0 L/min)

What other certifications should DIYers know?

WaterMark is a certification that captures all of the above — it makes sure the plumbing fixtures you’re about to buy meet Australian standards for water quality, safety and performance. When purchasing tapware or other plumbing fixtures, check to see if they are WaterMark certified.

In plumbing code words, a WaterMark certification guarantees that the product is up to Australian standards AS/NZS 3718:2013.

DIY plumbing: What you can and can't do

Plumbing regulations can change depending on where in Australia you are. For example, waterproofing your bathroom is fine in Victoria but illegal without a plumber in New South Wales. In general, most plumbing work should be done by a licensed plumber. However, you can legally do minor tasks like:

  • Changing tap washers
  • Replacing a showerhead
  • Unblocking a drain with a plunger

Call a professional for anything more complicated, especially involving pipework, mains water and hot water systems. They'll ensure the work meets code and take the stress out for you.

Staying up to date on plumbing code 

Plumbing codes evolve. Stay updated by:

  • Checking the Australian Building Codes Board website
  • Consulting your local council for specific requirements
  • Talking to licensed plumbers about current best practices
If you’re shopping with Yabby, you can be confident your tapware is high quality and meets all plumbing codes. For more info on how our products comply with Australian plumbing standards, go to our listings or get in touch with our team.
Layla Sawyer
Layla is a creative at heart, with an Advanced Diploma in Interior Design and being the Senior Marketing and Ecommerce Coordinator here at Yabby she has a passion for staying up to date with the latest trends within the industry. Known for going down a rabbit hole on Pinterest and being a sucker for a good mood board to kick off any project.