Developer Thrive Construct recently announced the the tallest steelwood hotel in the world to be built in Victoria Square, Adelaide. Australia has embraced the trend of building taller with timber, along with other plans of three buildings 180-220 meters high submitted to Perth and Sydney. These would more than double the current world record for a wooden building.
High-rise wooden buildings, made entirely of solid wood (layers of wood glued together) or hybrid steel-wood and wood-concrete construction, are gaining popularity around the world. Every two months, an even taller wooden building seems to appear somewhere. My colleagues and I joke that we have stopped trying to keep up.
Wood is a sustainable and renewable material that stores carbon during use, and the appeal of its use in skyscrapers is clear. But I fear that focusing only on height means we forget about the “middle”: apartment buildings, hospitals, schools, and shopping malls. Buildings like these are dominated by concrete, steel and brick, all of which are carbon or energy intensive materials.
The ‘middle’ isn’t sexy and probably won’t make the news, but this is where wood construction can have a significant impact on sustainability.
Read more: Tracking the transition: ‘Forgotten’ emissions undo the work of Australia’s renewable energy boom
Change is difficult. Developers and designers favor familiar materials and construction methods where cost estimates are straightforward. Wood requires a change of mindset and early involvement of contractors to be cost competitive.
But if we really want to do something to reduce our country’s carbon footprint, the entire construction industry urgently needs to changewith Australian government support, towards renewable and low-carbon construction materials and methods. It means to build with wood if we can, use steel and concrete if we have to.
Wood technology transforms construction
The Australian timber industry has adopted solid timber such as glued laminated timber (glulam or GLT) for beams and columns, and cross-laminated timber (CLT) for panels. Solid wood is more homogeneous than sawn wood, which translates into greater strength and allows us to build higher than ever. australia third CLT plant is set to open in 2023 in South Australia.
Globally, wood has reached new heights over the past 15 years. Notable projects include the University of British Columbia project Municipalities of Brock student housing, 53 meters high and made of solid wood and concrete. The tallest wooden building until recently was the 85 meters high Mjøstarnet in Norway, entirely in CLT and glulam. He lost his title to Ascentan 86-meter, 25-story wood-concrete tower in the United States.
By comparison, the tallest buildings in Australia to date reach only ten stories. The Australian “first” was that of Lendlease Forte Melbournea CLT apartment building completed in 2013. Aurecon’s 25 King Street in Brisbane was Australia’s first open-plan office building, standing 52 meters tall and constructed entirely of solid timber.
Another interesting “grand-ish” wooden building is Kangaroo Point of Monterey luxury apartments in Brisbane. Developers Gardner Vaughan opted for a relatively lightweight solution of CLT and a single concrete core, as the building sits above the Clem Jones Tunnel.
Australia are determined to go high in the woods. The University of Queensland Future wood pole studies how to build taller wooden buildings, including extensive research on fire safety. A better understanding of fire behavior has led to a change in legislationlifting height limits on wooden buildings and building developer confidence plan much taller buildings.
Building at height in wood is a technically difficult and exciting art for engineers and architects. I’ve known this since I studied the seismic design of connections in large wooden buildings for my doctorate. I’m still involved in big wood research with the Council for Tall Buildings and Urban Habitatand European research on Holistic design of taller wooden buildings.
And what’s not to love about the wood? It virtually grows on its own, stores carbon in sustainable wood products, can be cascaded into other wood products, and used as fertilizer for sustainable end-of-life forests.
But building taller and taller wooden buildings alone is not the answer to the climate crisis.
In 2011, Forest and Wood Products Australia (FWPA) reported on the opportunities and constraints of wood construction. Its report identified multi-residential, educational and office buildings as having the greatest potential for wood construction.
Almost all of these buildings are still constructed of concrete and brick. Despite efforts to make both materials “greener”their production currently consumes large amounts of non-renewable resources and emits a lot of carbon.
Read more: Green cement is one step closer to changing the game on construction emissions
So what’s stopping us?
The FWPA report identified the biggest problem as the lack of timber construction expertise. This is not surprising, since Australian universities hardly offer courses in wood.
The University of Tasmania offers a postgraduate certificate in timber design for professional engineers. The University of Queensland is the only other Australian university to offer a dedicated timber design course for undergraduate structural engineering students.
In response to the lack of knowledge of wood in the construction industry, WoodSolutions, the educational arm of the FWPA, has set up a whole medium-sized business consulting program. It allows those exploring mid-rise timber solutions to get free information and advice from a panel of experts.
Advancing the education of structural timber engineering is only one piece of the puzzle. It also takes a change of mentality to move beyond the idea that wood can only be used in individual single-family homes. In fact, we have to get away from these houses completely. The federal HomeBuilder grant program has led to a nationwide wood shortage and added to urban sprawl.
Read more: Wood shortages set to delay home construction until 2023. These 4 graphs show why
Instead, we must embrace well-constructed mid-rise apartment buildings of engineered wood. This material can safe use of inferior wood and relieve pressure on wood supply.
Large wooden buildings are exciting, and we must not stop dreaming big, but we must focus on the missing link to make construction sustainable.
Correction: CLT’s third Australian factory is expected to open in Tarpeena, South Australia, not Tasmania as originally reported in this article.