25 King, Brisbane, Qld

Australia’s largest engineered timber commercial building, designed by Bates Smart, has opened in Brisbane. At 10 stories and 45 meters in height, the 25 King open plan office complex is the tallest timber structure in Australia and establishes new frontiers in the design of commercial buildings. The scheme’s aesthetic is centered on the goal of bringing a clear expression of its exposed structure to the building’s transparent envelope and promoting a warmer, more natural workplace environment of the future.

The structure features a hybrid of glued laminated timber (Glulam) and cross laminated timber (CLT) elements, reflecting the architect’s research into engineered timber technology to meet modern-day and future demands for function and sustainability. The departure from steel and concrete as primary structural elements results in a significantly lower carbon footprint, with sequestered carbon locked within the timber structure.

The structure is raised on massive exposed timber v-columns, with a south façade verandah of engineered timber. Nine levels of open-plan office space are serviced via a north-facing core, above a ground floor timbercolonnade of public cafes and restaurants. The form of the scheme draws inspiration from the wooden vernacular “Queenslander” building type, and historic pavilions in the surrounding Showgrounds district.

The use of exposed CLT slabs internally has eradicated the need for suspended ceiling systems, opening the floorplates to a larger ceiling height, softer surfaces and acoustics, and a warmer atmosphere. Set along a 6 x 8 meter grid determined by the span of the Glulam ceiling beams, the scheme’s columns are arranged to offer an intimate open-plan scale without hampering flexibility.

The scheme’s adherence to sustainable principles has produced dramatic savings, with a 74 per cent reduction in embodied carbon, 46 per cent reduction in energy, 20 per cent weight saving compared to concrete, and a construction period of just 15 months aided by offsite prefabrication.

Design: Lendlease & Bates Smart

Photography: Tom Roe