ABCB clarifies concessions for use of timber framing and non-combustible materials on low-rise class 2 and 3 buildings

The Australian Building Codes Board has published an advisory note clarifying the application of concessions permitting the use of timber framing in some low-rise class 2 and 3 buildings of Type A and B construction.

The Victorian Building Authority (VBA) welcomes the decision of the Australian Building Codes Board (ABCB) to publish an advisory note clarifying the application of concessions permitting the use of timber framing in some low-rise class 2 and 3 buildings of Type A and B construction. The concessions are contained in Specification C1.1, Clauses 3.10(a) and 4.3(a) of Volume One of the National Construction Code (NCC).

The release of this advisory note comes after the Victorian Government last week announced the launch of a world-first rectification program to deal with high-risk cladding. The VBA sought clarification of the concessions from the ABCB in the interests of public safety, having scrutinised the work of Victorian practitioners through its Statewide Cladding Audit.

The VBA understands that some practitioners have interpreted the concessions in a manner inconsistent with the original intent of the Code. Specifically, a consequence of an alternative interpretation was the installation of combustible cladding materials on some low-rise class 2 and 3 buildings as a deemed-to-satisfy (DtS) solution.

In Victoria, to comply with Minister’s Guideline MG-14, any performance solution for Type A or B construction proposing the use of expanded polystyrene or aluminium composite panels with a polymer core of 30 per cent or more must be referred to the Building Appeals Board for determination. The results of this requirement will improve the fire safety of existing and future building stock for Victorian residents and the wider community.

The ABCB advisory note confirms that the intent of the concessions is confined to permitting the use of timber framing or a combination of timber framing and non-combustible materials in some circumstances. As a result, any building designed to comply with these DtS concessions must still retain non-combustible building elements such as external cladding.

The ABCB has committed to proceeding with an out-of-cycle amendment to Volume One of the NCC that will include clarification of the relevant concessions. This process will include a consultation period allowing stakeholders to comment on the proposed changes.

The ABCB’s Guide to Volume One of the NCC provides further information on the appropriate application of these concessions.