The Plumbing Code of Australia explained (NCC Volume Three)

What is the Plumbing Code of Australia?

The National Construction Code (NCC) has three volumes. Volumes One and Two cover the construction of buildings, and Volume Three, the PCA, sets the technical requirements for the installation of plumbing and drainage systems. It is published by the Australian Building Codes Board (ABCB) and is free to read online.

The PCA applies to plumbing in every class of building, from a house to a hospital. It sits alongside the other volumes rather than under them. A building surveyor or certifier will usually assess the building against Volume One or Two, while the plumbing installation is regulated under the PCA by the state’s plumbing regulator.

Our guide to the National Construction Code explains how the three volumes fit together.

How is NCC Volume Three structured?

The PCA follows the same Section-Part-Type-Clause numbering used across the NCC. In clause B1D2, for example, “B” is the section, “1” is the part, “D” means a Deemed-to-Satisfy Provision and “2” is the clause number. In NCC 2025 Volume Three the sections are:

• Section A, Governing requirements. How to interpret and comply with the NCC, referenced documents, evidence of suitability and building classification.
• Section B, Water services. Cold water, heated water, non-drinking water, fire-fighting water services, cross-connection control, rainwater services and rainwater storage.
• Section C, Sanitary plumbing and drainage systems. Sanitary plumbing, sanitary drainage and on-site wastewater management.
• Section D, Excessive noise. Noise from plumbing systems.
• Section E, Facilities and ancillary additions. Facilities.

Schedules follow, including Schedule 1 (definitions), Schedule 2 (referenced documents) and Schedules 3 to 11, which contain Commonwealth, state and territory variations and additions. Those state schedules matter in practice. Queensland’s variation to B1D2 of PCA 2022, for example, requires 4 Star WELS-rated fixtures in certain new Class 1 and 2 buildings.

What are Performance Requirements and Deemed-to-Satisfy Provisions?

The PCA uses the same compliance structure as the rest of the NCC. The Western Australian Building and Energy technical note on PCA 2025 summarises the clause types:

• Governing requirements (G). Mandatory rules on how the PCA must be used.
• Performance Requirements (P). Mandatory statements of how a plumbing system must perform.
• Deemed-to-Satisfy Provisions (D). Optional prescriptive rules that are deemed to meet the Performance Requirements.
• Verification Methods (V). Optional tests or calculations that show a Performance Requirement is met.
• Objectives and Functional Statements (O, F). Guidance on intent, not mandatory.

A plumbing system may comply through a Deemed-to-Satisfy (DTS) Solution, a Performance Solution, or a combination of both. Almost all everyday plumbing uses the DTS route.

How does the PCA use the AS/NZS 3500 series?

The DTS Provisions point to the AS/NZS 3500 series for the detailed design and installation rules. In PCA 2022, B1D3 states that a cold water service must be in accordance with AS/NZS 3500.1. The other parts cover sanitary plumbing and drainage (Part 2) and heated water services (Part 4), with Part 0 as the glossary. Stormwater drainage is covered by AS/NZS 3500.3, which NCC Volume One calls up for buildings.

The edition matters. According to Building and Energy WA, Schedule 2 of PCA 2025 lists the referenced documents from 1 May 2026, including updated AS/NZS 3500:2025 Parts 1, 2 and 4. A plumber working in both Victoria and New South Wales may therefore be working to different editions of the same standard on the same day.

Some requirements once inside AS/NZS 3500 have been moved into the PCA itself because they are matters of policy rather than pure technique. Building and Energy WA gives the example of B2D5 and B2D6, which set maximum temperatures and the types of devices used to deliver heated water for personal hygiene. Those PCA clauses apply in addition to the referenced standard.

What is WaterMark certification?

The WaterMark Certification Scheme is a mandatory certification scheme for certain types of plumbing and drainage products. It is managed and administered by the ABCB. Its purpose is to make sure products are fit for purpose and authorised for use in plumbing and drainage installations.

The legal hook is clause A5G4 of the PCA. In PCA 2022:

• Products on the Schedule of Products. A product of a type listed on the WaterMark Schedule of Products is deemed fit for its intended purpose if it holds a WaterMark Licence issued under the WaterMark Scheme Rules.
• Products on the Schedule of Excluded Products. These do not need WaterMark certification, but still need evidence of suitability, such as a current certificate from a certification body or a report from an Accredited Testing Laboratory.

The ABCB’s explanatory information gives examples of products needing certification, including copper alloy fittings, valves such as isolation and backflow prevention valves, taps and mixers, water meters, pumps, water heaters and residential water filtration equipment. Certified products carry the WaterMark trademark and licence number and can be checked on the WaterMark Product Database.

Lead-free requirements now sit on top of WaterMark. A plumbing product or material in contact with drinking water must have a weighted average lead content of no more than 0.25%. From 1 May 2026, manufacturers can produce only Lead Free WaterMark certified products of the affected types, and from 1 May 2028 plumbing practitioners must install them. The ABCB notes that states and territories may vary these transition arrangements.

How do the states adopt the PCA?

The ABCB writes the PCA, but it has no legal force until a state or territory’s plumbing legislation calls it up. That is why adoption dates, variations and enforcement differ across the country. Building and Energy WA describes the hierarchy in Western Australia as the Plumbers Licensing Act 1995, then the Plumbers Licensing and Plumbing Standards Regulations 2000, then the PCA, then AS/NZS 3500, then manufacturers’ specifications.

For NCC 2025, the ABCB’s adoption information shows:

• Victoria. Adopted from 1 May 2026.
• Western Australia. Adopted from 1 May 2026, with a 12-month transition period.
• ACT. Adopted from 1 May 2026, with a 12-month transition period.
• South Australia. Plumbing Code adopted from 1 May 2026, a year ahead of the building code on 1 May 2027.
• New South Wales and Queensland. From 1 May 2027.
• Tasmania. 1 May 2027, with a transition period running from 5 June 2026.
• Northern Territory. Not adopted, so NCC 2022 continues to apply.

States also limit which parts are regulated. In Western Australia, Building and Energy notes that only water supply, sanitary and drainage plumbing work is currently regulated, and Regulation 48 lists the PCA parts that apply. In South Australia, the Technical Regulator’s Plumbing Standard, made under the Water Industry Act 2012, requires installations to comply with relevant parts of the PCA. Our guide to NCC 2025 adoption dates tracks the building volumes.

Who licenses plumbers in each state?

Plumbing licensing is entirely a state and territory matter, so the rules differ in scope, terminology and paperwork. Key examples are:

• New South Wales. Plumbing, draining and gasfitting is specialist work, so a licence is needed regardless of the value of the work. Work must be notified to the plumbing regulator and a certificate of compliance provided, using the combined Notice of Work and Certificate of Compliance.
• Victoria. The Building and Plumbing Commission (BPC) regulates plumbers. Each class of work has two levels: registration lets you carry out the work, while a licence also lets you design, supervise and issue compliance certificates.
• Queensland. The QBCC issues occupational and contractor licences under the Plumbing and Drainage Act 2018. Regulated work is classed as permit work, notifiable work or minor work, and notifiable work must be registered with the QBCC.
• Western Australia. Plumbing is regulated under the Plumbers Licensing Act 1995, and the Plumbers Licensing Board deals with licensing and Performance Solution notices.
• South Australia. The Office of the Technical Regulator sets the technical Plumbing Standard, separately from the licensing of plumbing contractors and workers.
• Tasmania, the ACT and the Northern Territory. Each has its own licensing body: Consumer, Building and Occupational Services in Tasmania, Access Canberra in the ACT, and the Plumbers and Drainers Licensing Board in the NT.

A licence in one state does not automatically let you work in another, so check mutual recognition or automatic recognition arrangements with the regulator before taking work across a border.

When is a Performance Solution needed in plumbing?

A Performance Solution is needed when a design does not follow the DTS Provisions, for example a new drainage layout, an unusual heated water arrangement or a product used outside its DTS limits. It must show that the relevant Performance Requirements are met.

Under A2G2 of PCA 2025, as summarised by Building and Energy WA, the assessment methods include evidence of suitability, a Verification Method in the PCA, another verification method accepted by the appropriate authority, expert judgement, and comparison with the DTS Provisions. A2G2(4) then sets out mandatory steps: prepare a performance-based design brief with the relevant stakeholders, carry out the analysis, evaluate the results against the brief, and prepare a final report identifying the Performance Requirements, the assessment methods, the results and any conditions or limitations.

State procedures sit on top of that. In Western Australia, Regulation 45A requires a contractor to submit a notice of intention for plumbing work involving a Performance Solution at least five working days before starting, with supporting evidence to the Plumbers Licensing Board. Other states set their own approval routes, so confirm the process with the regulator before work starts. Our guide to Performance Solutions covers the general process.

How does the PCA cover backflow, water efficiency and rainwater?

Several of the most commonly inspected topics live in Section B. Cross-connection control in Part B5 deals with protecting drinking water from contamination, and is explained in our guide to backflow prevention. Water efficiency in B1D2 links fixtures to the Water Efficiency Labelling and Standards (WELS) scheme. Rainwater services and rainwater storage are in Parts B6 and B7.

Building and Energy WA notes one detail worth knowing: Schedule 2 of PCA 2025 still lists AS/NZS 3500.1:2018 to adopt the backflow requirements for top-up devices to partially and fully buried rainwater tanks.

PCA compliance checklist

• Confirm the edition. Check whether PCA 2022 or PCA 2025 applies in your state on that date.
• Read the state schedule. Check the variations and additions for your state or territory.
• Use the right standard. Work to the AS/NZS 3500 edition listed in Schedule 2.
• Check the PCA clauses too. Apply policy clauses such as heated water temperature limits.
• Check WaterMark. Confirm listed products carry a current WaterMark licence.
• Plan for lead-free. Specify Lead Free WaterMark products for drinking water ahead of 1 May 2028.
• Hold the right licence. Confirm your registration or licence covers the class of work.
• Notify and certify. Lodge notices and compliance certificates as your state requires.
• Document Performance Solutions. Keep the design brief, analysis and final report.

Frequently asked questions