For more than a century, countries have raced to build the world’s tallest buildings with concrete and steel. Now, a quiet contest in constructing tall wooden buildings, from Amsterdam to Tokyo, underlines growing environmental concerns over concrete.
With rapid advances in engineered wood, and authorities relaxing building codes, wooden structures are sprouting across Europe, Canada, the United States, and in the Asia Pacific region.
At 73 metres (240 ft), Amsterdam’s Haut building is said to be the world’s tallest wooden residential tower.
Vancouver plans a 40-storey building it says will be the world’s tallest, a title also claimed by Sumitomo Forestry’s 350-metre skyscraper in Tokyo.
“The interest is definitely being driven by environmental concerns – the amount of damage we’re doing with concrete is unbelievable,” said John Hardy, a sustainability expert in Bali, Indonesia.
“Bamboo and wood are carbon sequestering materials. So, the other advantage of building with them is that you will look better to your children and grandchildren,” he said.
Construction of office towers, bridges, airports and highways is booming in developing nations across the world.
The manufacture of steel, concrete and brick accounts for about 16 per cent of global fossil-fuel consumption – and up to 30 per cent when transport and assembly of the materials is considered, according to the Yale School of Forestry & Environmental Studies.
Concrete is also blamed for rampant sand mining, which has damaged the environment and hurt livelihoods in Southeast Asia.
In addition, an abundance of concrete has worsened urban flooding, and made cities hotter, environmentalists say.
In contrast, wood requires fewer fossil fuels to transport and assemble, and also effectively stores large amounts of carbon – trapped as the trees grew – for years, helping curb emissions, said Andy Buchanan, professor of timber design at the University of Canterbury in New Zealand.
Each cubic metre of timber used in construction stores a carbon equivalent of over 900 kilogrammes of CO2 emissions, meaning a reduction of 135 kg-360 kg of CO2 emissions per square metre of floor area, said Buchanan.