In discussions about humanity’s impact on the planet, conversations invariably turn to our treatment of the world’s rainforests.
We continue to cut down large swathes of forest every year, with an area almost the size of South Africa lost since 1990, according to the UN Food and Agriculture Organization.
Activities such as illegal logging, deforestation to create farmland, and domestic heating and cooking suggest timber use will always be synonymous with ecological degradation.
But to label wood use as unsustainable does the material a great disservice.
Timber is in fact a versatile, easy to use (and reuse) aesthetically pleasing natural product which, if trees felled are replaced and forests and woodlands carefully managed, will never run out.
In fact, with new wood technology, timber is as strong, durable and fire-resistant as steel. And that is not all. Substituting a cubic metre of wood for other construction materials, like concrete, blocks or bricks, results in a 0.75–1 tonne CO2 saving, storing carbon, unlike manmade materials that require huge amounts of fossil fuels and harmful emissions to produce. Meanwhile, as a report from the Timber Development Association in Australia shows, timber buildings are 10–15 per cent more cost effective than other materials across many building types.
Architects are catching on.
Timber-framed building is enjoying a renaissance, accounting for 70 per cent of all new houses built around the world today. And advances in technology mean timber will increasingly be shaping the skyline, with taller and bigger timber buildings built, planned or in development around the world.
30 storey wooden buildings
The winning proposal for British football club Forest Green Rovers’ new 5,000-seat stadium, for example, relies entirely on wood. Designed by Zaha Hadid Architects, it will be the world's greenest football stadium, powered by sustainable energy sources and located within a newly-created nature reserve.
In Bergen, Norway, a major co-operative housing association has shown that concerns about fire safety and stability that have limited wood buildings to only a few storeys are outdated. BOB BBL’s 14-floor Treet apartment block is the world’s tallest wooden building. “Treet is a lighthouse project to show how we can make cities grow in a sustainable way,” explains Ole Herbrand Kleppe, the project’s chief manager and developer.
The 62-apartment structure relies on a clever modular design and on an engineered wood product – glued laminated timber (Glulam) – which provides consistent quality and strength, improved structural performance and predictable fire resistance. Kleppe predicts that “the technologies and knowledge from this project will make it possible to build similar buildings 25 to 30 storeys high”.
Windows, packaging and solar panels
The resurrection of wood in modern life does not stop at architecture. Wood’s properties and structure are also being harnessed in new manmade materials like porous ceramics, which could in future be used as catalyst supports or heat exchangers or even as implants to treat bone disorders in the elderly.
Researchers from Sweden's KTH Royal Institute of Technology have found a way to create transparent wood that could be used to replace solar panels, windows or even plastic products. Starting from thin strips of wood veneer, they strip the brown lignin and replace it with a polymer to create a composite that is almost completely transparent. Currently, the wood has been produced only in the lab; the next challenge is to scale the technology and make its expensive production process affordable.
Until recently, cost was also a problem for another wood-based material, nanocellulose. Cellulose is the building block of wood and many other natural products: “Cotton, flax, hemp and pulp are all made of cellulose fibres,” says Mikael Lindstrom, Senior Scientist at Innventia, a government-owned Swedish forest raw materials research institute. When cellulose is tweaked to have at least one dimension less than 100 nanometres in size, it forms nanocellulose, a new material that conducts electricity, is stiffer than Kevlar and eight times as strong as steel.
Touted as the next big technology, nanocellulose could find applications in everything from biodegradable food packaging and flexible electronics to lightweight recyclable vehicle parts, biodegradable building insulation, and as an additive to cement to make it stronger.
Innventia has made huge strides in the commercialisation of nanocellulose. For instance, they managed to reduce the energy consumption of nanocellulose production by 98 per cent via a chemical and/or enzymatic pretreatment. With the production process using a similar amount of energy to polypropene – the second-most widely produced synthetic plastic – this innovation encouraged the company to open the world's first pilot plant for nanocellulose production in 2011, with a capacity of 100 kg/day. More recently, they teamed up with renewable packaging company BillerudKorsnäs to build a mobile demonstration factory for industries without their own testing facilities.
Elsewhere, Canada’s CelluForce is the world leader in producing a particularly promising form of nanocellulose – nanocrystalline cellulose (NCC). “Cellulose provides the kinds of properties we appreciate in wood and paper products,” explains CelluForce’s Richard Berry. “But the real strength within the fibre is in the NCC.” Indeed, NCC has been called nature’s carbon nanotube, promising many of carbon nanotubes’ properties but more safely and at a lower cost. “It is now, when large quantities are available at a fair price, that the real exploitation starts!,” adds Lindstrom.
