The National Construction Code (NCC) Volume One, Building Code of Australia, allows the use of timber construction systems under the Deemed-to-Satisfy (DTS) Provisions for Classes 2 (Apartments), 3 (Hotels) and 5 (Office Buildings) up to 25 metres in effective height - approximately 8 storeys tall.

The provisions cover both ‘Lightweight’ and ‘Massive’ systems such as Glue Laminated Timber (GLT). Both require the use of fire-grade plasterboard – termed ‘fire-protected timber’ in the NCC – and automatic fire sprinklers. Cavity Barriers are specified for Lightweight to address the risk of fire spread via cavities.

For specific design information, download the Wood Solutions Design Guide #37 Mid-rise Timber Buildings.

Timber is naturally an insulating material that creates a barrier between heat and cold.

The secret can be found in the many air pockets within the cellular structure of timber products, meaning that lightweight timber is a better insulator as thermal conductivity increases with density.

Construction design with a focus on energy efficiency through lightweight timber can greatly contribute to maximising comfort and minimising non-renewable energy use. In addition, timber framed buildings can allow for extra insulation materials to be placed in spaces between framing members without increasing wall, ceiling, roof or floor thickness. The natural thermal properties of timber also maximise the efficiency of insulation materials as wood will not become cold or dissipate heat, therefore requiring less energy to maintain warmth throughout a building.