Cross-laminated timber1 September 2016
by Charlotte Christie
Cross-laminated timber (CLT) was a mystery to me until I attended a talk by David Lomax of Waugh Thistleton Architects at last month’s Vision London event for architects, clients and suppliers in Olympia.
David explained that CLT is an engineered-wood alternative to traditional timber where boards of wood are stacked at angles and glued together. It is strong, lightweight, versatile to use, cost-effective and offers thermal and fire resistant qualities.
Waugh Thistleton designed its first building using CLT in London in 2003. Since then other projects have included Murray Grove in Hackney, which completed in 2008 and is the world’s tallest modern timber residential building. CLT offers various environmental advantages, including carbon benefits. In this case, using it saved 1,150 tonnes of CO2.
Discussion forum New London Architecture (NLA) has shortlisted Murray Grove in its ‘New Ideas for Housing’ study for ‘Grow London’, a tall timber project. This is how the book A Process Revealed describes the project:
“Client, architect, engineer and manufacturer worked closely to deliver an extraordinary nine storey residential development in central London. The tallest building of its kind, it has an entirely wooden structure from the first floor up. The building pushes the boundaries of timber use in modern construction and will profoundly affect the way we build in the future. The design team intends to make the processes developed for the construction widely available, so others considering this versatile and environmentally friendly material may use this book as a guide.”
Waugh Thistleton joins a few others in the built environment that are exploring new methods and techniques in buildings using CLT. In Finland, the OOPEAA Office for Peripheral Architecture has used it innovatively in the Puukuokka Housing Block. The goal was to provide affordable housing of the highest quality that was environmentally responsible. Using prefabricated, modular CLT helped it achieve that.
Investors and developers, including Legal & General (L&G) Homes and Regal Homes, are on board too. At Vision, Rob Hall from L&G Homes discussed mass production CLT Modular units as a new solution to the shortage of suitable, affordable and sustainable housing.
With the government forecasting that 500,000 new homes will be needed by 2025, is there an opportunity to increase the use of CLT, to mitigate the housing shortage for both buyers and renters?
In terms of industry competition, it remains to be seen how ‘fast-track’ materials like CLT will affect suppliers and builders’ merchants, like Travis Perkins. Already there is a growing trend among architects to go directly to CLT suppliers and manufacturers, for example in Austria and Germany.
However, if CLT is going to get off the ground in a big way, a few things need to happen. First, the building industry needs to remove embedded behaviours that suggest a resistance to change – the ‘we’ve always done it this way’ culture. Opening minds to new materials is vital if the built environment is to realise and quantify the benefits of CLT.
So early engagement throughout the construction eco-system will be a key driver in adopting CLT and other modular building methods, with architects leading this thinking.
Other industry changes will affect CLT’s use. The supply chain is struggling as it tries to engage with building information modelling (BIM), which the government calls ‘the most ambitious and advanced centrally driven programme in the world.’ It is a collaborative working method using digital technologies to manage information throughout a project.
If the industry is to deliver value to a client, it will need to think differently and more openly. CLT can bring about a change in perception, thereby changing the culture of construction and its practitioners.
For example, integration, innovation and a change in attitudes are needed when using CLT as the construction time is shorter than traditional methods. Developers and clients would also need to make quicker decisions, possibly within 24 hours due to the speed of working with CLT.
At the same time, developers want buildings quicker to achieve a return on their investments. Off-site construction is the most viable way forward to retain the quality to deliver high spec solutions.
And to ensure bigger investment in CLT, the industry will need to attract institutional funding from companies like Aviva. With size and financial power on its side that shouldn’t be too hard.
In July 2013, The Department for Business Innovation & Skills document about UK Construction states that: “Construction is one of the largest sectors of the UK economy. It contributes almost £90 billion to the UK economy.”
So it is an exciting time for the industry as fledgling activity begins in the market. It presents opportunities to form partnerships to boost the innovative, sustainable and economic solutions that CLT provides in the future
With thanks to Dave Lomax at Waugh Thistleton Architects and Alison HarmerRead more...