The world’s tallest office tower made entirely out of engineered timber is set to be built in Australia by the end of 2018. With nine storeys and a height of 45 metres, the new design as already considered the future of modern construction. Barbara Barkhausen reports from Sydney.
Australia likes to adorn itself with superlatives. Whether the office tower to be built on King Street in Brisbane by the end of 2018 will actually be the tallest all-timber tower in the world – as its owner currently claims – doesn’t really matter.
What does count is that the 45-metre high office tower with its nine storeys is an architectural novelty.
Designed by the Australian architecture firm Bates Smart, the building will be made of engineered timber or Cross Laminated Timber (CLT). CLT is when several layers of wood are glued together under high pressure with the grain of each perpendicular to the one before.
Considered by many to be the future of construction, it achieves a structural stability and strength akin to concrete and steel.
Good for your health
A high-rise made out of wood has a number of advantages. According to a study from the Australian environmental organisation PlanetArk, using wood as a building material reduces blood pressure and heart rate. It is also environmentally friendly, in contrast to concrete which generates 900 kilograms of greenhouse gases for each tonne used.
“Buildings made from engineered timber have a lower carbon footprint than other building materials: the production process produces zero waste, and timbers are sourced from certified sustainably managed forests,” according to the developer, Lendlease.
Engineered timber projects also generate less noise pollution during construction, and the structures, which can be plugged in together similar to Lego or an IKEA kit, can be erected much faster than those built using traditional construction methods – up to six times faster for the all-timber office tower planned for Brisbane.
Fire hazard concerns
Australia’s building code was changed last year to permit medium-rise timber structures, but one of the major outstanding concerns is that they pose a fire hazard – and not just since the tragic Grenfell Tower fire in London, which shows just how dangerous flammable materials can be when used in high-rises.
And the concerns over wood are justified. At least in its historical context: the 19th and 20th centuries were plagued by fires in cities worldwide, which led to the development of new, less-flammable building materials such as steel and concrete.
But times have changed. According to Nick Hewson, a technical manager with the New Zealand-based engineered wood supplier XLam, the new wooden buildings require sprinklers and fire-resistant linings, and when the wood is cleared, it must be thick enough.
“[With thick wood] you can subject it to long periods of fire exposure,” the expert told the Guardian.
Construction in the 21st century
Australia is by no means the only country building timber high-rises. A French architecture firm is planning to build six green wooden towers in India by 2020, and Vienna will soon be home to a 24-storey, 84-metre-high building with a timber construction of 75 per cent.
Britain’s University of Cambridge has even presented plans for an 80-storey, 300-metre-high wooden tower to be built in London. Michael Ramage, the director of the Centre for Natural Material Innovation in Cambridge, even calls timber construction “the future of construction” in the 21st century.
“We believe people have a greater affinity for taller buildings in natural materials rather than steel and concrete towers,” he said.
Ramage and other proponents of wooden towers also don’t see a problem when it comes to obtaining wood. Canada alone could produce more than 15 billion cubic metres of crop forests in the next 70 years – enough to house a billion people.