Late last year, nearly 18 months after they first sat down to consider the next edition of the National Construction Code (NCC), Australia’s Building Ministers agreed to the deferral or removal of several NCC proposals. While this appears to be an acceptance that states cannot regulate their way to productivity and housing targets amid shifting priorities and international crises and distractions, some states are finding it harder than others to break the habit.

HIA set out to ensure that the proposed changes to NCC 2025 were achievable by the residential building industry, avoiding a repeat of the scale and disruptive impact of NCC 2022. 

While this has resulted in an NCC with a far more commercial focus, it didn’t start out that way. Below, we recap on the proposals that are progressing, the numerous improvements and concessions to proposals incorporated since public comment, and which states plan to move first.

The path to NCC 2025

• 1 May–1 July 2024: The NCC public comment draft was released for consultation. It included residential changes to energy efficiency in common areas of apartment buildings, condensation management, electrification policy, carpark fire safety and revised external waterproofing and water shedding provisions, among others.
• October 2024: Building Ministers met and agreed to delay the Code’s publication while further improvements to its content were made.
• August 2025: Following the federal government’s productivity roundtable, the federal Housing Minister announced that further residential changes, except for urgent safety issues, would be paused until mid-2029. 
• October 2025: Commonwealth, State and Territory Building Ministers met and agreed to remove several proposals from the final version of the NCC.
• 1 February 2026: NCC 2025 Preview was released on the Australian Building Codes Board (ABCB) website.

The ministers’ October 2025 announcement on NCC 2025 included agreement on which matters in the NCC would progress and those which would not. Proposals progressing included external waterproofing for public buildings and apartment balconies, commercial energy efficiency stringency increases, carpark fire safety, and condensation management changes. 

Significantly, in response to industry feedback, a few proposals were withdrawn. This included proposals HIA had argued were underdeveloped and inappropriate for inclusion in the NCC at this stage, relating to the installation of electric vehicle chargers for all car-parking spaces in residential and commercial buildings; thermal break changes; and a rushed embodied emissions proposal included after the conclusion of public comment. 

Major changes in NCC 2025

While it is pleasing that several of the proposed NCC 2025 changes were either improved or not progressed, some that remain will impact design and material selection for residential builders. Some of the significant changes include:

• Governing requirements: Changes regarding the assessment of Performance Solutions for fire and structure will restrict the use of ‘expert judgement’ as a means of assessing core structural and fire safety solutions. In a break with convention, a new Verification Method for structural safety will become a mandatory obligation for new or novel materials (subject to a transition period of 12 months from the date of adoption).
• Condensation management: In response to public comment, there has been a reduction in scope and stringency of changes for condensation management’s cavity widths and ventilation obligations for roofs; a restructure of the provisions for increased clarity; and exemptions where it was neither practical nor intended to provide condensation management.

This has resulted in clearer provisions for cathedral and pitched roofs. Specifications for external wall construction and roof ventilation have changed to reduce the risk of condensation. However, the changes will mean more roof ventilation and all Deemed-to-Satisfy (DTS) alternatives for wall cladding requiring a drained and vented cavity in colder climate zones (6–8). 

• Australian Standards: 36 new amended or revised NCC Referenced Standards have been incorporated into NCC 2025, including key residential standards:- revised wind loads for housing (AS 4055)- amended timber framing (AS 1684 Part 2, Part 3 and Part 4)- revised swimming pools (AS 1926.1)- a new NCC referenced standard for expanded insulation finish systems (EIFS) (AS 5637).

These referenced documents become a compliance option on adoption of NCC 2025. More significantly in the longer term, NCC 2025 will mark the introduction of the ability to use referenced documents which have been considered and approved by the ABCB outside of its amendment cycle, once listed on a new alternative referenced document register.

• External waterproofing: NCC 2025 Volume One (Class 2–9 buildings) contains new external water management provisions that involve a full restructure of Performance Requirements, new defined terms which change the scope of water managed by the part and new DTS provisions for Class 2 apartment balconies constructed of concrete. A further reconciliation of the provisions occurred following public comment in recognition of some more practical alternatives for balcony water-shedding.

• Commercial energy efficiency for Class 3 and Class 5–9 buildings: Amendments to the NCC’s stringency for these buildings target ‘near net zero’ operational energy use. Changes have been made to the Performance Requirements, Verification Methods and DTS to reflect this level of stringency. HIA had argued Class 2 common areas were not modelled in ABCB analysis and should be removed from the Commercial Energy Efficiency proposals. While yet to be reflected in the online preview, the ABCB website confirms the decision.

HIA has recently launched its online NCC 2025 hub which provides a comprehensive summary of the major changes, new and revised referenced standards, and links to information sheets and further detail to assist members’ understanding. 

Adoption across the states

The NCC is brought into force in each state through reference in regulation. 

HIA has recommended states adopt a transition period commensurate with the scope of the changes being adopted, along with enhanced implementation support. 

With adoption by states comes the potential for Variations and Additions, some of which could undermine national agreements. 

This has already proven to be the case in Victoria, where NCC 2025 will apply to new building work and bring forward lead-free plumbing products to 1 May 2026, varying a (national) extension to that transition. In a potentially significant deregulatory move, Victoria has also announced changes to a swathe of variations to the NCC. 

The detail on which variations will go is not expected until their enactment. In Queensland, NSW, and SA, NCC 2025 adoption has been deferred to 1 May 2027 and NCC 2022 remains in force until then.

In Western Australia, building regulations recognise the edition of the Building Code that was in effect 12 months before the application for the building permit is made.

In the ACT, after 1 May 2026 and before 1 May 2027, projects with building approval may comply with either:

• NCC 2022 and the ACT 2022 Appendix; or
• NCC 2025 and the ACT 2025 Appendix. Projects with Building Approval after 1 May 2027 must comply with NCC 2025 and the ACT 2025 Appendix, with the following exception:
• Projects with a Development Application or Works Approval Application formally lodged before 1 November 2026 may continue to seek Building Approval under either NCC 2022 or NCC 2025 until that Development Application expires.

The Northern Territory will not adopt NCC 2025. Tasmania is deferring significant changes, having previously announced it would not be adopting the NCC or specific changes.

Advice on key residential changes

HIA’s NCC 2025 hub is members’ go-to source for the latest NCC information, including the latest adoption announcements, advice and tips on how to comply with NCC 2025 changes in your state. 

All three volumes of NCC 2025 are available on ABCB online. 

If you have questions on compliance with building-related obligations, HIA’s Building Services Team are here to help.

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