2025 National Construction Code (NCC) - Volume One Building Code Of Australia

What is NCC Volume Three?

The NCC is divided into 3 volumes. Volume Three covers technical requirements for the design and construction of plumbing and drainage systems in both new and existing buildings. Volume Three applies to these systems in all classes of buildings whenever plumbing work is carried out, and additionally applies to sites where water services are constructed independent of buildings. 

As a performance-based code, it sets the minimum required level for the safety, health, amenity, accessibility and sustainability of certain buildings. 

Key Updates in NCC 2025

Lead-Free Plumbing Products - Now Mandatory

PCA 2025 requires copper alloy plumbing products in contact with drinking water to be certified under WaterMark and carry the Lead Free WaterMark logo. Relevant plumbing work commenced on or after 1 May 2026 must comply with these requirements.

Cross-Connection Control Restructured

 Cross-connection hazard provisions previously contained in Specification 41 of NCC 2022 have been relocated to Clause B5D7 and updated. Marinas are now classified as high hazard properties, rather than medium hazard, for containment protection purposes. These provisions have also been updated to introduce exemptions for sites not connected to a Network Utility Operator (NUO).

Fire Hydrant System Material Requirements

A new subclause has been added to require all above-ground pipes and fittings used to supply fire hydrant systems, including combined sprinkler and hydrant systems, to comply with the material requirements of AS 2419.1 for above-ground hydrant pipework.

Sanitary Plumbing — Upgraded Compliance Standard

All sanitary plumbing installations must now fully comply with AS/NZS 3500.2. The existing Verification Method for sanitary drainage pipe sizing has been improved, and frequency factors and discharge unit values have been updated

Heated Water System Limitation

A new limitation has been introduced for heated water systems to avoid imposing an additional burden on dwellings that already comply with whole-of-home energy efficiency provisions.

Rainwater Supplementation Now Permitted

A new exemption allows rainwater storage to be supplemented with drinking water where required.

Language & Editorial Clarity

Several clauses in NCC 2025 have been updated editorially to improve consistency in language and structure across the Code volumes. In many instances, these are minor language changes only and do not represent a technical or policy change.

Why Choose NCC 2025?

It Is Now the Law in Most States

Volume Three of the NCC (the Plumbing Code) was adopted from 1 May 2026. In Victoria, South Australia, and Western Australia this is already in force — using NCC 2022 for new plumbing work after this date creates real compliance and liability risk.

Avoids Mixing Code Versions

Whichever code version a project uses, it must be nominated and applied consistently. A project cannot mix provisions from NCC 2022 and NCC 2025.

Clearer Performance Pathways

NCC 2025 includes clarified performance requirements and improvements to water services, cross-connection control, and sanitary plumbing and drainage systems.

Benefits of NCC 2025

• Public health protection
• Greater flexibility
  
• Reduced fragmentation
  
• Safer fire services
  
• Energy and water efficiency
• Clearer language

Who Needs NCC 2025?

• Licensed plumbers and drainers
• Hydraulic engineers and designers
• Building inspectors and certifiers
• Architects and building designers
• Construction project managers and developers
• Educators and students