World’s tallest wooden building to be built in Perth after developers win approval

Western Australia is set to become home to the world’s tallest timber building, a “revolutionary” 50-storey hybrid design reaching a height of 191.2 metres.

Timber will make up 42% of South Perth’s C6 building, including the tower’s beams, floor panels, studs, joinery and linings.

The Grange Development project at 6 Charles Street will include more than 200 apartments and was approved by Perth’s Metro Inner-South Joint Development Assessment Panel on Thursday. The developers say it will be carbon negative, storing more carbon than it uses and will combine lightweight, durable, renewable glued laminated timber and cross-laminated timber with lower amounts of steel and concrete than conventional construction methods.

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It will also be taller than Atlassian’s hybrid timber headquarters, currently under construction in central Sydney, which will be 180 metres high. The world’s tallest timber building, Ascent in Wisconsin, US, stands at 86.6 metres with 25 storeys.

Architect and principal of Fraser and Partners, Reade Dixon, said the project, which does not yet have a construction timeframe, is revolutionary in an industry that hasn’t changed much in its approach to commercial buildings over the past 70 years.

The building’s developers claim that the 7,400 cubic metres of timber consumed by C6 could be regrown in just 59 minutes from one sustainably farmed forestry region.

“C6 will consume approximately 580 pine trees sourced from sustainably managed and farmed forests,” the project’s website states. “We can’t grow concrete.”

C6 will house edible and floral gardens on its rooftop.

Dixon said the timber in the project would either come from Australia’s largest mass timber producer, XLam, in Albury, NSW, or be shipped from Europe in empty iron ore ships returning to WA.

The director of the University of Wollongong’s Sustainable Buildings Research Centre, Timothy McCarthy, said the developer’s claims do not include end-of-life carbon costs of timber.

“Currently, the end of life scenario for timber is landfill – people are working on getting this changed but the IPCC [Intergovernmental Panel on Climate Change] only considers permanent sequestration for materials, and timber eventually rots or burns, returning its CO2 to the atmosphere,” he said.

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While the trees used in the design come from fully sustainable sources, McCarthy noted only 40% of a tree ends up as timber - the rest is ploughed back into the land or made into mulch, while some goes towards paper making.

Although the ambitious design was a “tough task”, he praised the project’s approach.

“[C6’s] ambitions are to be lauded and if it can deliver that sustainability over the full life of the building, we are changing the playing field, particularly in WA, where the climate is very harsh,” he said.

Fraser and Partners will open-source publish all technical materials from the project. The aim is to encourage more mass timber architecture in the built environment in response to the climate crisis, said Dixon.

“Our great hope is that it challenges the industry to do future projects better,” he said.

Construction accounts for 11% of global carbon emissions, while cement alone is responsible for 8% of all carbon emissions. In 2020, WA generated 81.7m tonnes of CO2, or 16% of Australia’s emissions.