Timber buildings, or “plyscrapers”, are on the rise across Australia and worldwide, with developers now rewriting the century-old rule book on construction commercial, residential and mixed-use developments.
A plyscraper is a skyscraper made (at least partly) of wood – and Australia, thanks to T3 Collingwood (in Melbourne), Atlassian Central Tower, the Milligan Group hybrid tower (both in Sydney) and C6 (in Perth) is among the global leaders in the push to build tallest timber buildings.
That’s because “timber is a great choice, as it’s effectively the anti-concrete,” according to Professor Philip Oldfield, the author of The Sustainable Tall Building: A Design Primer, who said mass timber-based buildings and vertical extensions are the key to driving the next generation of construction.
“What’s happening at the moment is a much greater understanding of something called embodied carbon,” according to Professor Oldfield, head of the School of Built Environment in the University of NSW’s Faculty of Arts, Design and Architecture.
“For any new building today in Australia, you look at its greenhouse gas emissions, and about half of them will be due to embodied carbon. That’s the carbon in the materials and construction of the building before it even opens – something we used not to consider much,” Professor Oldfield said in an interview with the Australian Financial Review this morning.
“We’ve got regulations to limit the energy used for lighting, heating and so on, so we can reduce that [but] there are no regulations to reduce embodied carbon. So, there’s a lot of focus on developing technologies and strategies around this.”
In October, the NSW Government became one of the first jurisdictions in the world to introduce new legislation that made developers and architects accountable for measuring embodied carbon in building designers.
According to Professor Oldfield, by increasing the use of timber up to 30 per cent of all new multi-storey buildings by 2050, Australia can get the built environment down to zero emissions.
“Every square metre we build has a carbon footprint, which can be quite high because the materials we rely on to construct buildings are very carbon intensive.”
“Any new building constructed in Australia today, we expect at least half of its total carbon footprint over its life will be embodied carbon, possibly even more.”
He also points to vertical extensions, where materials are upcycled and adapted to existing materials – including reworking the 1976 AMP Centre in Sydney’s Circular Quay.
In April, Australian-based World Architecture Festival judge Mark Thomson reported exclusively for Wood Central that the expanded 1970s office tower had been extensively recycled and transformed. The new building repurposes the former AMP Centre at 50 Bridge Street, initially designed by Peddle Thorp and Walker and built-in 1976.
“Two-thirds of the beams, columns, floor slabs, and almost the entire core built has been retained,” Mr Thomson said, adding that “this saved almost 12,000 tonnes of carbon dioxide compared to complete demolition and conventional new construction tons.”
Oldfield, 41, studied architecture in the UK and the US and moved to Australia in 2015; he says the motivation to build tall has a long history.
“If you go back to 16th-century Bologna, for example, different families would build towers to demonstrate their power and wealth. The taller you build, the more powerful and more wealthy you are,” he told the Australian Financial Review.
“Fast-forward 500 years, it’s the same. China, the Middle East, and America have all built skyscrapers to demonstrate a kind of technological prowess to a global audience.”
“The Burj Khalifa in Dubai is the world’s tallest building at 828 metres. There’s no functional, economic or any other need for it, but it was built to put Dubai on the map, and that brought with it its economic benefits for tourism and global reputation,” he said, with Wood Central revealing last year that Dubai is now turning to timber skyscrapers for future development.
Instead, Professor Oldfield believes the reworked AMP Centre in Sydney’s Circular Quay, now known as the Quay Quarter Tower, is a better template for the future.
“It’s probably where we’re going to go with a lot of tall buildings.”
“The original office building on the site was too small, wasn’t efficient any more, wasn’t financially viable. So they cut the front off and extended it out and up, increasing the floor area by about 50 per cent while retaining 65 per cent of the underlying structure. That saved about 12,000 tons of carbon.”
Many existing buildings are strong enough for vertical extensions, with Professor Oldfield adding that architect Bates Smart was able to add ten additional levels to a six-storey building at 55 South Bank “because the new floors used mass timber, which is much lighter than traditional materials.”
Another approach is the hybrid structure, which might mean a concrete core, a steel frame and timber floors. “With that kind of structure, you could potentially build 70 to 80 storeys,” says Oldfield.
“Atlassian’s new headquarters, for example … has a concrete core, a steel frame, and then essentially a series of four-storey timber buildings, stacked up to 40 storeys within that frame.”
But back to the pure plyscraper, which Oldfield says is gaining momentum in Australia and not just thanks to adventurous architects.
“Developers are finding you can build quicker using mass timber. It’s often easier to build because it fits together like Meccano.”
He says there are also fewer wet trades on site, and you need fewer people to do the job.
“Universities are also using mass timber more because of the short windows of opportunity between teaching terms to get the construction done.”
Most mass timber panels are held in place with steel joints or brackets, hence the Meccano reference. This makes it possible to deconstruct such a building more easily and reuse the pieces.
A timber building has a different vibe because you don’t see the structure in a conventional office building.
“In a mass timber building, we typically remove the ceiling and expose all the timber. There’s a warmth to it,” Professor Oldfield said, with Hines Global Real Estate, now using timber buildings as a “magnet to attract “A-grade tenants.”
Emerging research suggests being around natural materials like that can reduce stress and potentially increase productivity.
“I think a number of commercial organisations are seeing those kinds of benefits, or at least are exploring those benefits in a much more optimistic way.”
Oldfield is looking forward to a future with fewer generic glass towers in favour of more exciting and efficient buildings with more opaque facades and shading.
Exposed timber creates a feeling of warmth inside International House, Barangaroo – another project recently crowned “Building of the Year” by the World Architecture Festival.
“We’re also moving away from tall buildings just being icons, and focusing on the building environmentally, and providing amenities for the people inside.
“There’s been a shift in the mentality. I’m hoping we can use tall buildings for humanity and create great places to live and work that are more in tune with the environment. Good design is paramount to that.”
- For more information about Professor Oldfield and how plyscrapers and hybrid timber buildings can be used to drive decarbonisation, please visit Wood Central’s special feature on the NSW embodied carbon requirements, which occurred in October 2023.
