There were times when Stan Chiao and Eijiro Kosugi, both visionaries in their field, felt like giving up. Yet despite the odds, the two architects are still working hard to convince sceptics that wooden buildings are the way forward.
Based in the Taiwan city of Taichung, Chiao realised one of his dreams in 2014 with completion of the WoodTek headquarters building. A futuristic, five-storey edifice, which also happens to be Chiao’s own office, it was Taiwan’s first building made from cross-laminated timber, or CLT.
‘It was certainly a struggle,’ admits Chiao. ‘When we started planning our office in 2009, nobody understood the potential of wooden buildings. There were many bureaucratic hurdles to cross.’
Kosugi, who spent almost 10 years trying to get a wooden shop and apartment complex built in Tokyo, also understands the frustration of complying with ultra-strict and outdated regulations. His project was finally realised in 2013, with a ground floor made from reinforced concrete.
‘Wood has the potential to completely disrupt modern construction methodology,’ says the Japanese architect. ‘But many people, especially in Asia, still need convincing.’
CLT is an innovative material that’s been developed over the past two decades, offering numerous advantages over its more conventional construction counterparts. Frequently described as plywood on steroids, it is manufactured by gluing together multiple layers of timber boards, which are oriented so the grain of each board crosses the next one at 90 degrees. While lengths of timber expand and contract along the grain, the opposing timber boards counteract this effect, making it a material of great rigidity.
‘Structurally robust, CLT is a lightweight, aesthetically pleasing alternative to steel and concrete,’ says Esther An, chief sustainability officer of Singapore-based real estate developer City Developments Limited, which is co-developing the Singapore Sustainability Academy, one of the city’s first CLT buildings.
CLT is sustainable too, creating a much lower carbon footprint in the manufacturing and building processes than steel and concrete. It also makes economic sense. Thanks to its light weight, the foundations of CLT buildings can be relatively shallow, while an emphasis on prefabrication encourages advanced planning. The latest wooden buildings are typically 30 percent cheaper and constructed 50 percent quicker than those built with traditional materials.
‘With regard to construction, the use of CLT for the Singapore Sustainability Academy is expected to increase productivity by more than 30 percent and save around 130 man days,’ says An. ‘It will also provide a high level of thermal performance, reducing cooling costs.’
Understandably, one of the common concerns about using wood is the danger of fire. Yet thanks to the way CLT panels char, it is just as fireproof as steel or concrete. Fire resistance can be further increased by adding plasterboard linings and chemical retardants.
CLT was first developed in Austria, and Europe currently leads in the material’s use. In the UK, for example, there are now over 500 CLT buildings, with virtually every major house builder now considering the material. In areas where local councils are under pressure to achieve carbon reduction targets, CLT structures are even becoming mandatory.
Many Asia-Pacific countries are now playing catch up. Places such as Singapore and Taiwan are erecting their first CLT buildings, and a Chinese delegation visited Europe in June 2016 to learn about modern timber construction methods. Australian developer Lendlease has overseen the construction of four CLT buildings, while the country’s first CLT plant is set to start operation in 2017.
In Japan, a heavily forested country, CLT will be used in the design of the new National Stadium in Tokyo and other 2020 Olympic facilities. By offering subsidies, the Japanese government is now pushing CLT manufacture and use in order to stimulate local economies and drive down prices.
‘Japanese people love wooden spaces so a growing number are interested in CLT,’ says Aya Utsumi, chief architect at KUS, a Tokyo-based architectural practice involved in a number of CLT projects. ‘Decreasing costs are a key factor.’
Modern wood structures are not only spreading eastward; they’re also pushing skyward – nearly 20 buildings over seven storeys high have been constructed over the past five years. In 2015, a 33-metre-high apartment block called The Cube was completed in London’s Shoreditch district, becoming the tallest CLT structure in Europe, according to developers, although it may soon lose its crown to a building in Norway. Both would be dwarfed by the Splinter, a 300-metre, 100-storey timber tower proposed for London.
But around the world, many inexperienced clients are still nervous about committing to wood. ‘I’d say the biggest obstacle to CLT use today is people’s perception,’ says Andrew Waugh of London-based Waugh Thistleton, an architectural practice that is pioneering tall timber buildings. The firm was responsible for the Stadthaus, one of the British capital’s first CLT buildings, completed in 2009.
There is also a lack of experience and expertise with the material in some markets. In Taiwan, for example, where up to three-quarters of buildings are still made from concrete, most universities don’t teach timber engineering. Despite this, Chiao remains optimistic about WoodTek’s prospects. ‘Our clients are changing their thinking,’ says the designer. ‘They want a better and more natural environment in which to live and work.’
If current trends in construction and technological development continue, then the use of CLT and other forms of engineered timber is likely to become the norm in the very near future. Factors such as carbon taxes, resource scarcity and an ever increasing awareness of environmental issues will all contribute to the mushrooming of wooden architecture across the globe.
‘We are now at the beginning of the timber age,’ says Waugh. ‘We’ve been building the same way for a hundred years. Now it’s time for a revolution. It’s time to plant some trees.’