Information session on the Plumbing Code of Australia 2025

All right. Good morning, everyone. It's now clicked over to 11. Um welcome to today's presentation on the key changes to the Plumbing Code of Australia 2025. My name is Adrian Piani. I'm CEO of the Australian Building Codes Board. And I appreciate you taking the time to join us today. Many of you will know the Plumbing Code of Australia or PCA as Volume 3 of the National Construction Code commonly known as the NCC. The PCA sets the national technical requirements for plumbing and drainage systems in and around buildings. As practitioners regulators and industry representatives your work plays an essential role in ensuring these systems are safe reliable and fit for purpose. Today's session is designed to help you understand the most significant updates and what they mean in practice. So, before we begin I would like to acknowledge the traditional custodians of the land where I am here in Canberra the Ngunnawal people and acknowledge the traditional custodians of the lands from which you are all joining today. I pay my respects to elders past and present and recognize their continuing connection to country, culture and community. I also extend that respect to any Aboriginal and Torres Strait Islander peoples joining us today. The presentation will focus on three questions. What has changed? Why do these changes matter? And what do practitioners need to do differently? We'll cover updates relating to water services cross-connection control, rainwater, sanitary plumbing and drainage, reference standards, and evidence of suitability. While today's presentation provides a high-level overview of the changes, we encourage you to explore the detailed amendment list and supporting resources available on the ABCB website. So, before we get started, just a few housekeeping items. Your camera and microphone are off. A short Q&A session will be held at the end of the presentation. You can submit questions at any time. Please submit questions using the Q&A function. We'll do our best to answer as many questions as we can. If we don't get to yours, please check our website resource library. It may already be covered there. The session will run for approximately 1 hour. Today's session is being recorded and will be made available on the ABCB YouTube channel. We will notify stakeholders once the recording is available. Please note that the Q&A session will not be included in the recording. With that, I'll hand over to Richard Plain to take you through the key changes. Thank you, and I hope you find today's session valuable. >> Thanks, Adrian. My name is Richard Plain, and I'm the plumbing director of the ABCB. Thank you for taking the time to be here today. This presentation is designed to provide a practical overview of most significant PCA 2025 changes. Whether you work with the PCA every day, or you need to refer to it occasionally, I'll explain the main changes, identify the relevant provision references, and describe each change means in practice. Let's start off by looking at the major changes to the PCA by section. This slide groups the changes into four areas. First area is section A, which contains the NCC governing requirements. These rules explain how compliance is demonstrated, how reference documents are used, and what evidence may be accepted. The second area is section B, which deals with water services. This includes cold water, heated water, non-drinking water, fire fighting water, cross-connection control, and rainwater systems. The third area is section C, which deals with sanitary plumbing and drainage. The main changes are revised verification methods for determining wastewater flow and verifying system design. The fourth area is reference documents and guidance. PCA 2025 adopts updated editions of the AS/NZS 3500 series and introduces a control process when using an approved alternative edition. A useful starting point is volume three list of amendments. It identifies the changed provisions and helps practitioners decide which changes are relevant to a particular project. Section A, governing requirements. Before looking at the plumbing provisions, it is helpful to understand section A. Section A contains rules that apply across the NCC, including volume three. A2G2 explains the assessment methods that may be used for a performance solution. A performance solution is an alternative way of meeting a performance requirement when the proposed solution does not follow the complete deemed to satisfy pathway. A4G1 deals with reference documents. PCA 2025 introduces the alternative reference documents register as an option to schedule two. An alternative edition can only be used through this pathway when it's included in the register. For a deemed to satisfy solution or an NCC verification method, one edition must be used consistently. Provisions from different editions cannot be mixed unless the resulting approach is demonstrated through a performance solution. A5G6 concerns evidence of the fire hazard properties and combustibility. This may be relevant when a plumbing products, service penetrations, or associated construction interact with fire safety requirements. For a practitioner who's new to the PCA, practical message is simple. First, identify the suitable requirement, then identify the compliance pathway. Finally, make sure the evidence supports the exact product design and intended use. Section B, water services, contains the requirements for water services. Parts B1 to B7 cover different service types, but PCA 2025 gives these parts a more consistent structure. Across the relevant parts, access and isolation are now expressed as separate outcomes. Access means being able to reach a component for inspection, testing, maintenance, or replacement. Isolation means being able to shut off the relevant service section or component. These concepts are related, but they are not the same. An isolating valve may be in the correct hydraulic position, but still be difficult to reach. A valve may also be easy to reach, but shut off a larger area than intended, such as a whole floor instead of one tenancy. The change supports better design review, installation, commissioning, and maintenance. Part B1 covers cold water services. There are three main points on this slide. First, B1P2 is the performance requirement for water velocity. PCA 2025 introduces V1V1, a new verification method for determining whether a proposed cold water service satisfies that velocity requirement. A verification method is an assessment method. It gives a recognized way to test whether a performance requirement has been met. Using B1V1 forms part of a performance solution pathway. It is not the same as following the deemed to satisfy provision provisions in AS/NZS 3500 part one. Second, access and isolation are separated. B1P3 deals with access, and B1P4 deals with isolation. The design should therefore show both where serviceable components are located, and how the required parts of the system can be shut off. Third, B1D3 2 clarifies that plastic pipes and fittings must not be used above ground in a combined sprinkler and hydrant system. This resolves uncertainty created by the different material rules that may apply under the sprinkler and hydrant standards. For plumbers and reviewers, the practical effect is that hydraulic performance, access, isolation, and material suitability must each be considered. Satisfying one of these outcomes does not automatically satisfy the others. Let's look at B1/V1 in more detail, including how the method works and the potential benefits it may provide. B1/V1 is an optional verification method for determining whether a proposed cold water service satisfies the velocity requirement in B1/P2. It does not replace the deemed to satisfy provisions in AS/NZS 3500 Part 1. Where B1/V1 is used, it forms part of a full solution pathway. The method starts by determining a probable simultaneous design flow. It uses a probability-based approach that considers how fixtures are expected to be used rather than assuming that every connected fixture operates at the same time. The resulting high design flow is commonly described as the Q99 flow. In practical terms, Q99 represents a high probable flow for the assessed fixture population and use pattern. It provides a design flow input for assessing velocity in each relevant pipe section. The next step is to assess velocity using the actual internal diameter of the proposed pipe. This is important because two pipe products with the same nominal size can have different internal diameters. The selected product and its actual internal bore must therefore be consistent with the calculation. One One potential benefit of B1/V1 is that the cold water pipe work can be assessed using a more project-specific design flow. Where supported by the calculation, this may allow pipe work to be matched more closely to the probable demand rather than being based on a more conservative assumption about simultaneous fixture use. This may support more efficient use of pipe materials and associated installation components. However, any reduction in pipe diameter, materials, or installation inputs is potentially a project outcome, not an automatic benefit of using B1/V1. Another benefit is that B1/V1 provides transparent and reproducible design basis. Consistent, the assessment should identify the connected fixtures, adopted probabilities, flow rates, pipe sections, and actual internal diameters used to obtain the results. A reviewer should be able to examine the scope, assumptions, and inputs, and reproduce the controlling results. It is important to understand that scope of the method B1/V1 addresses the B1/P2 velocity requirement only. It does not verify every aspect of the cold water service. The complete hydraulic design must still consider the available supply pressure, elevation, friction loss through pipes and fittings, fixture flow and pressure requirements, noise, water hammer, and pipe limitations. For example, a branch servicing an upper floor level shower may satisfy B1/V1 velocity requirement, but still have excess pressure loss. In that situation, the pipe may need to be larger, the design may need to change, or another design response may be required. Product substitution must also be checked. A replacement pipe may be the same nominal size as the specified pipe, but a different internal diameter. This may change the calculated velocity and pressure loss, meaning the original assessment may no longer apply. The installed system must therefore remain consistent with the product's dimensions, fixture population, and your assumptions used in the assessment. Where a change affects those assumptions, the relevant part of the design should be reviewed before the change work proceeds. The practical benefit of B1 V1 is not simply small pipework. It is more accurate and evidence-based method for assessing cold water velocity that may support design optimization where the complete hydraulic assessment demonstrates satisfactory performance. The key message is that B1 V1 may allow cold water pipework to be better matched to probable demand, but it does not automatically justify the smallest pipe. The complete cold water service must still perform as intended. B2 heated water and B3 non-drinking water. This slide covers two parts with a similar drafting approach. Part B2 covers heated water services. B2 P3 has been clarified including the treatment of flow velocity in non-copper circulatory systems. This matters because excessive velocity in a heated water circulation system can contribute to noise, erosion, and reduced system life. B2 P4 now deals with access and P2 B5 deals with isolation. P2 D2 also updates the minimum small scale technology certificate values and provides a limited option to use relevant volume two provisions in specified circumstances. Part B3 covers non-drinking water services. The force requirements are now arranged more clearly, including separate requirements for access, isolation, pressure, uncontrolled discharge, and water efficiency. For someone unfamiliar with the PCA, a non-drinking water service may include water used for toilet flushing, irrigation, or another approved purpose. The service must be clearly identified and protected against cross-connection with the drinking water service. The common practical message is that each service must perform hydraulically, remain identifiable, be accessible for maintenance, and be capable of appropriate isolation. Part B4 covers firefighting services, including hydrant systems. PCA 2025 separates the key performance requirements. B4P2 addresses access, B4P3 addresses isolation, B4P4 addresses firefighting water storage, and B4P5 addresses uncontrolled discharge. B4D4 recognizes a fire hydrant system installed in accordance with AS 2419 part one, AS 2118 part six where suitable, or FPAA 101H where applicable. This provision identifies the applicable systems pathways rather than creating a material restriction. The material restriction is addressed in B1D3. Plastic pipes and fittings must not be used above ground in a combined sprinkler and hydrant system. So, the plumbing specification and fire design need to be considered together. The change also has cross volume connection because volume one recognizes combined sprinkler and hydrant systems in the relevant fire safety provisions. For practitioners, the action is to confirm the system type, the relevant standard, the location of the pipework, and the material limitations before products are ordered or installed. Part B5, cross connection control, protects water services from contamination caused by cross connections. A cross connection is an actual or potential connection through which contaminated water or another substance can enter a water service. Backflow may occur through back siphonage when upstream pressure falls or back pressure when downstream pressure becomes greater than supply pressure. In PCA 2022, the detailed hazard scenarios were in specification 41. In PCA 2025, specification 41 was deleted and the contents of specification 41 relocated to B5 D7 within part B5. This is mainly a structural and usability improvement. The hazard scenarios now sit beside the provisions that use the hazard ratings. Most familiar low, medium, and high hazard examples remain. Although some descriptions have been clarified. One example is the wording for handheld personal washing hoses. PCA 2022 referred to handheld bidet hoses and trigger sprays. PCA 2025 now refers to handheld bidet or douche hoses and trigger sprays. The addition of the douche hoses makes the listed scenarios easy to recognize where the terminal that terminology is used for the product or installation. This is primarily a clarification of the existing hazard description rather than the creation of a new hazard category. Consider a handheld bidet or douche hose installed beside a toilet. The assessment should be based on the complete installed arrangement, not only the product name. A key practical consideration is whether the hose outlet can reach into the toilet pan and create an actual or potential cross connection. This is an example of a recognizable hazard addressed by B5 D7 listed scenarios. Other cross connections may require further assessment because not every possible individual or zone hazard is included in the list. B5 D7 and B5 V1 assessment sequences. The handheld bidet or douche hose is an example of a hazard addressed by a listed B5 D7 scenario. However, not individual or zone hazards will be adequately covered by the B5 D7 list. The following three-step process explains how to deal with listed and unlisted hazards. Step one is to compare the connection with the scenarios identified in B5 D7. Practitioners should consider the actual operational circumstances of the connection, including its intended use and potential contaminants, rather than relying solely on the product name or classification. Where a scenario in B5D7 is relevant, the corresponding prescribed hazard rating shall be assigned. Step two applies when no B5D7 scenario adequately covers the individual or zone hazard. B5V1 can then be used to determine the hazard rating through a performance solution pathway. For a chemical hazard, the assessment considers the substance that could enter the water service, its likely concentration, possible chemical mixtures, the connection arrangement, and the consequences of exposure. A safety data sheet is useful in evidence, but it does not determine the PCA rating by itself. Step three is to select suitable backflow protection. The backflow device must suit the determined hazard rating and the possible backflow mechanism. The design must also consider orientation, pressure, drainage, access, testing, and maintenance. B5V1 cannot be used to lower a rating already described by B5D7. It also deals with individual and zone hazards, not the separate contaminant requirements imposed by network utility operator. The key point is to determine the hazard first and select the device second. B6 and B7 rainwater. PCA 2025 makes rainwater systems easier to understand by separating the service side from the storage side. Part B6 covers the rainwater service. In simple terms, this is the downstream pipework that carries rainwater from the storage connection to the points where the water is used. Part B7 covers rainwater storage. This includes the tank, the entry of rainwater, overflow arrangements, and the connection from storage to downstream services. Both parts include clear requirements for access and isolation. The broader framework also deals with matters such as contamination protection, pressure, velocity, identification, and water efficiency where relevant. For example, a building may use tank water for toilet flushing, laundry, or irrigation. A reviewer should be able to identify the tank side obligations, the service side obligations, and the point where the two systems connect. Each Any connection to a drinking water supply must use the permitted arrangement and include appropriate cross-connection protection. The rainwater pipework must always be suitably identified so that it is not mistaken for drinking water. Access and isolation across section B brings the reoccurring access and isolation change together. For access, ask whether a person can reach the valve, pump, backflow device, water heater, filter, or tank component for the work it will need during its service life. For isolation, ask whether the correct part of the service can be shut off. The answer should be based on the intended operation and maintenance arrangement, not simply on whether any valve exists. These matters should be checked during design coordination. A valve shown in an accessible position on a hydraulic drawing may become blocked by a ceiling, covered duct, or another service. The check should be repeated during installation and at completion. Access that exists before fit out may be lost after finishes and joinery are installed. The aim is a plumbing system that remains practical to test, maintain, and replace without causing unnecessary disruption to unrelated parts of the building. Section C covers sanitary plumbing and sanitary drainage. Sanitary plumbing generally refers to pipework within the building that receives discharge from fixtures and conveys it to the sanitary drainage system. Sanitary drainage generally refers to the graded drainage system that conveys the wastewater towards the point of connection. The main PCA 2025 change is a clearer verification framework. The process separates the wastewater load from the capacity and arrangement of the proposed system. In simple terms, the first question is how much wastewater must the system carry? The second question is can the proposed pipes, grades, junctions, and the other components carry that flow safely? C1 sanitary plumbing verification. In PCA 2022, sanitary plumbing verification was spread across C1 V2, C1 V1 to C1 V5. PCA 2025 simplifies the pathway into two linked methods. C1 V1 determines the sanitary plumbing wastewater flow rate. It establishes the hydraulic load produced by the connected fixtures and expected pattern of use. C1 V2 uses that flow rate to verify the sanitary plumbing design. It considers the proposed branches, stacks, and other relevant parts of the system. The revised methods may support more efficient pipe sizing where the calculation justifies it. They do not create a general permission to reduce pipe diameters. Pipe size is only one part of the design. Junction type, branch location, stack offsets, ventilation, and the relationship between connected fixtures can also affect performance. For example, a calculated design may be based on a particular apartment stack arrangement. Moving a bathroom group, adding a commercial fixture, or changing a branch connection may alter the assumptions and require the design to be reviewed. The practical message is that C1 V1 determines the load and C1 V2 verifies the sanitary plumbing capacity and arrangement. The installed system must match the assessed design. C2 sanitary drain verification. Part C2 applies the same general load and capacity logic to sanitary drainage. C2 V3 determines the sanitary drain wastewater flow rate. PCA 2025 revises this method. C2 V4 is a new verification method for sanitary drain design. It uses the calculated flow to assess matters such as pipe diameter, grade, junctions, invert levels, and downstream conditions. This distinction is important on site. Adding fixtures may change the C2 V3 flow rate. Changing the drain grade may leave the fixture load unchanged, but alter the C2 V4 result. For example, rock or another service may force a drain to be installed at a flatter grade than shown on the design. Keeping the same pipe diameter does not automatically preserve the verified performance. C2 P5 also makes contamination more visible as a distinct performance requirement. The design must prevent the sanitary drainage system from creating unacceptable contamination risk. The practical message is that C2 V3 determines the load, while C2 V4 verifies the capacity and arrangement of the drain. Related plumbing changes outside volume three. Some changes outside volume three directly affect plumbing work and coordination. The swimming pool drainage, volume one G1D5, and volume two H2D2 provide a deemed to satisfy pathway for pumped swimming pool discharge to sanitary drainage in accordance with AS/NZS 3500 part two. Network operator requirements still need to be checked. Volume one also recognizes combined sprinkler and hydrant systems in relevant fire safety provisions. This reinforces the core This references the need to coordinate the fire design with the material restriction explained on slide 10. Changes concerning roof, balcony, and podium drainage may affect outlet and location overflow arrangements, falls in coordination with structural substrates. The PCA should therefore not be read in isolation. A plumbing system may also be affected by volumes one or two, reference standards, jurisdictional legislation, and authority requirements. Reference documents. The NCC sets the required outcomes and relies on reference documents for much of the detailed design and installation information. Schedule two identifies the editions adopted by the PCA 2025, including the 2025 editions of AS/NZS 3500 plumbing and drainage series. The latest edition available for purchase is not automatically the edition adopted by the NCC. For every project, record the applicable NCC edition, jurisdiction, and reference document editions. A4G1 introduces the alternative reference documents register. The register provides a controlled way to use an approved alternative edition of a reference document before the next full edition of the NCC. A newly published edition cannot be used through this pathway unless it has been assessed and listed. Each register entry identifies where the alternative edition may be used and may include conditions, exclusions, or directions about secondary reference documents. Where an entry applies, a project may use either the schedule two edition or the listed alternative edition for the provisions [clears throat] covered by that entry. For a deemed to satisfy solution or an NCC verification method, use one edition consistently. Do not combine provisions from different editions. A mixed edition approach must be demonstrated through a performance solution. Record the selected edition and applicable register entry in the project documentation. The register does not apply to state or territory variations unless the entry states otherwise. Evidence of suitability is the information used to show that material, product, design, or form of construction is suitable for its intended use under the NCC. The ABCB evidence of suitability handbook provides a decision framework. It prompts users to check whether the evidence type is recognized by the NCC, current and relevant to the proposed application. Relevance is critical. A certificate or report may cover a product family, but not the exact model, size, material, configuration, or installation proposed. Where a WaterMark certification is required, a WaterMark license is important evidence. However, it does not automatically establish every aspect of the PCA compliance. Check the certified specification, authorized scope of use, conditions, and installation limitations. Apply the same approach to test reports, calculations, certificates, expert evidence, and assessment methods. Read the complete evidence, not only the title or conclusion. The handbook is guidance. It supports consistent assessment but does not approve a product or create a new evidence type. Practitioner checklist. This checklist turns the changes into project actions. At design stage, identify the NCC edition, jurisdictional variations, and applicable performance requirements. Confirm whether the solution is deemed to satisfy or includes a performance solution. Before purchasing or substituting a product, check the applicable filing standard, watermark requirements, evidence scope, and intended use. A substitution is a design and compliance decision, not only a purchasing decision. During installation, confirm that materials, internal diameters, grades, fittings, and layouts match the approved design. Keep required components accessible and ensure isolation operates as intended. If a change affects a verification method or hydraulic calculation, have it reviewed before proceeding. At completion, test and commission the system, record the standard editions used, and retain calculations, certificates, test results, conditions, and limitations. ABCB educational material. Before we wrap it up, I'd like to highlight some resources that can help you apply PCA 2025 in practice. After today's session, a good starting point is Volume Three list of amendments. It can help you quickly identify which changes are relevant to your projects and where those changes are located in the code. Once you identify the relevant provisions, make sure you confirm applicable reference document editions. Schedule two remains the starting point, and where relevant, the alternative reference documents register can help you determine whether an approved alternative edition is available. If your project involves a you a verification method, a performance solution, or a product evidence, resources such as the performance solution process handbook and the evidence of suitability handbook can help provide useful practical guidance. Finally, if you're looking to build your knowledge further, NCC tutor, CPD resources, and the plumbing and drainage resource library provide additional learning opportunities that you can assess at any time. As always, these resources are designed for understanding and application of the NCC. They do not replace the adopted NCC reference standards, jurisdictional requirements, or network utility requirements. PCA 2025 key takeaways. For water services, the major points are the new B1 V1 velocity method, clearer access and isolation requirements, and changes across parts B2 to B7. For cross connection control, specification 41 has moved into B5 D7, and B5 V1 remains the route for determining general unlisted individual and zone hazards. For sanitary systems, C1 V1 and C1 V2 provide a simpler sanitary plumbing pathway, while revised C2 V3 and the new C2 V4 makes entry drainage verification more explicit. For reference documents and evidence, PCA 2025 adopts the 2025 AS/NZS 3500 series, introduces the alternative reference documents register, and reinforces the need to check every scope and intended [clears throat] use. Overall, PCA 2025 is easy to navigate, but the changes still have practical consequences for design, product selection, installation, commissioning, and record keeping. I'd like to leave you with four key messages from today's presentation. First, access and isolation are now more clearly expressed throughout the water services provisions, and should be considered separately during design, installation, and maintenance. Second, several new and revised verification methods have been introduced. These methods can support more sophisticated design approaches, but they must be applied correctly and as part of a complete design process. Third, when dealing with cross connection control, determine the hazard first, and then select the appropriate backflow protection. Finally, always ensure you're working with the correct reference document edition, schedule two, and where applicable, the alternative reference documents register should be at your starting point. Overall, PCA 2025 is easier to navigate, but it still requires careful consideration of design, product selection, installation, commissioning, and record keeping. And I will now hand back to Adrian to kick off Q&A session. Thank you. >> Thank you, Richard, for the presentation. We've covered the main changes to water services, cross connection control, rainwater, sanitary plumbing and drainage, reference documents, and evidence of suitability. As always, the best starting point for any project is the adopted PCA, followed by the relevant reference standard, jurisdictional variations, and authority requirements. So, we'll now go through the questions, and remember to pop them in the chat.