11 July 2013 — Cross-laminated timber could provide a huge opportunity for a local manufacturing industry if government gets on board, says chairman and chief executive of Laminated Timber Solutions Tony Thorp.
CLT is a digitally designed and manufactured building material that can be used in place of conventional materials such as concrete. Timber boards are stacked in layers at right angles and glued together with non-toxic adhesives before being hydraulically pressed to make solid wood panels, creating a product with a high fire-resistance, good thermal insulation properties and improved strength.
Thorp says the product is a “true innovation in the construction industry” and is good for the environment because it is made from certified sustainable plantation timber, and may be able to sequester carbon for more than 100 years, potentially opening it up to qualifying as sequestered carbon under the Kyoto protocol definition.
The potential for sequestration of carbon through CLT and other plant-based building materials is huge. Thorp says that each cubic metre of CLT equates to nearly a tonne of CO2.
“My estimates of the latent market on the eastern seaboard alone for CLT and composite products is over one million cubic metres per annum in about 10 years time,” he says, “so we could be sequestering one million tonnes of CO2 per annum and thus sucking the equivalent from the atmosphere via the regrowth in the plantation forests from which the timber is sourced.”
A report from the UK found that policies designed to encourage increased use of all biogenic materials (wood, hemp, straw, wool etc.) in all UK buildings could have net carbon sequestration of up to 10 megatonnes of CO2 by 2020 and 22 MtCO2 by 2050.
To put this number in context, total carbon emissions from all UK construction activity in 2010 were 33MtCO2.
In Australia, Lend Lease’s Forté building in Docklands, Melbourne – the tallest CLT apartment building in the world – reduced carbon emissions by 1400 tonnes compared to if it had used steel and concrete. Forté this week achieved a 5 Star Green Star As Built rating, the second Green Star As Built certified apartment building in Australia, after Monash student housing.
Thorp says the Brits are world leaders in CLT technology but Australia was primed to be fast followers and could push into the Asia region.
“The issue we have currently is that we don’t have local manufacture,” he says. “CLT has to be imported, and that’s a barrier to cost and competitiveness.
“The main point about CLT is that one of the major efficiencies comes from using larger panels. The larger the panel, the more efficient the erection process.”
The importing of CLT puts a limit on the maximum sizes of panels, Thorp says, as shipping container size allows for a maximum CLT panel of 16 metres by five metres.
“Ideally, the product could be 24 m by 3.5 m, which could only be efficiently manufactured in Australia.
“A CLT timber industry would mean local manufacturing jobs that are very hard to displace by foreign manufacture. It’s putting the construction industry into prefabrication mode in a technology that is very hard to offshore.”
Thorp says on this basis is could be supported by government, and temporary policies could be introduced to build volume in the industry and reduce costs.
“It’s a matter of applying policy adjustment in a way that has as few adverse outcomes as possible.”
Some policy adjustments Thorp mentioned include a preferential government purchasing policy or temporary adjustments to planning permissions to allow for extra height for CLT buildings.
CLT, as a prefabricated technology, is also seen as a way to create more efficiency and a better occupational health and safety environment, shifting jobs from on-site to a factory.
“The construction industry has always been known as dirty, dangerous and demanding,” Thorp says, but CLT could help clean it up.
CLT also has some hurdles before being widely adopted. While projects like Forté have proven the commercial viability of the technology, it’s still seen as a risky venture.
“On a risk adjusted basis, it’s probably comparable to a traditionally framed building, but people still apply risk premiums because it’s largely still unknown,” Thorp says.
As a new technology, there are technological issues to be overcome, too. CLT has a low damping ratio, which can lead to problems with vibration, and certain acoustic frequencies may travel through the product more easily than with concrete.
Thorp says that there is a race to solve these issues and Australia could leverage this to become a world leader.
“There’s a lot of room for people to develop specific intellectual property,” he said. “If the industry here is given a bit of a boost, that level of innovation might provide a competitive advantage to be able to leverage that IP internationally.”
Australia might need to move quickly, as other countries are already planning groundbreaking CLT projects.
Google has just announced a new UK headquarters at King’s Cross in London built from CLT.
The one million square foot (92,900 square metres) “ground-scaper” features 725,000 sq ft (67,350 sq m) of office space and around 50,000 sq ft (4645 sq m) of retail space. Most of the internal structure will be constructed using steel framing with CLT panels, which is a first for a commercial building of this scale.
“The combination of CLT with steel frame opens up the potential for much larger structures and much broader adoption of CLT in the construction industry,” says Thorp.
Google says the building has been designed to meet the highest standards of environmental sustainability, ensuring low energy use and incorporating state-of-the-art materials.
They’ll be looking to score LEED Platinum and BREEAM Outstanding certification, and reduce carbon emissions by 40 per cent.
The design by architectural firm Allford Hall Monagham Morris will stretch 330 metres, with much of the rooftop being garden. The building ranges in height from seven storeys at the south end near King’s Cross Station to 11 storeys at the northern end overlooking Regent’s Canal. There will also be bicycle parking the size of seven tennis courts and a multi-storey climbing wall.