Architect Michael Green is predicting a revolution in wooden buildings that could help reshape the future of cities in a green way.
In a new video series with the Washington Forest Protection Association, renowned wood advocate Green says architects need to consider timber as a new and fundamental structural material.
The series sees Green speaking from his own firm’s wooden office – a 105-year-old, seven-storey building. Green believes high-rise wooden buildings are very possible and it’s an educational barrier rather than an engineering one.
Just like the world’s first steel skyscraper (William Le Baron Jenney’s 1884 Home Chicago Building) set in motion the beginning of rising steel structured skylines, Green now envisions the same will happen with wood in modern architecture.
“A century ago, it was a competition between different cities and developers to build skyscrapers and they really shaped the skylines of the world – I think we’re in that same phase right now,” he said.
With a residential skyscraper surge taking place around the world to support rapid urbanisation, the message from Green is clear: the time is now to prioritise wood as a strong, structurally viable and sustainable architectural material.
“We should be thinking about the environment every moment in design and thinking about the long term, the longevity of buildings,” he said.
“We’re going to have a major impact as the population grows, as people move into cities all the parameters are changing in the world and we really have to retool the way we build.”
Green cites some strong statistics in support of wood, including the fact that the manufacturing of steel, concrete and brick accounts for approximately 16 per cent of global fossil fuel consumption.
A report published in the Journal of Sustainable Forestry found that using wood substitutes could reduce global CO2 emissions by 14 to 31 per cent and fossil fuel consumption by 12 to 19 per cent by using 34 to 100 per cent of the world’s sustainable wood growth.
Wood is also a readily available renewable resource, with the report estimating that “the world’s forest contain approximately 385 billion cubic metres of wood, with an additional 17 billion cubic metres growing each year. A mere 3.4 billion cubic metres is harvested each year, mostly for subsistence fuel burning; the rest rots, burns in fires, or adds to forests’ density.”
In terms of the built environment, Green’s own research states that in a typical 20-storey building, concrete emits 1,215 tonnes of carbon dioxide while wood sequesters 3,150 tonnes of the gas for a net difference of 4,365 tonnes.
Additionally, carbon makes up approximately half the dry weight of wood.
“The forest and trees have this incredible advantage of both being lower energy materials to work with,” Green said.
Despite concrete and steel generally being perceived as the best material for high rise buildings, there are a few projects that have explored wooden heights using engineered timber.
Melbourne, Australia still holds the title for the world’s tallest timber residential building, the 32-metre Forte building. The 10-storey building is made of 760 panels of certified and manufactured cross-laminated timber.
London’s nine-storey residential building, Stadthaus, is but a few metres shorter, while the two-storey Merritt Building in Christchurch, New Zealand is the first earthquake-resilient open plan timber office building. It was built following the devastating earthquakes that shook the city in 2010 and 2011.
The University of Canterbury, which was behind the design and technology of the Merritt Building, says the “timber is threaded with high-tensile steel tendons and shock-absorbing steel componentry that enable the building to essentially spring back into alignment after a major quake.
In British Columbia, Canada, the Wood Innovation and Design Centre has partnered with Green to develop a 27.5-metre building wooden building which is almost complete, and Green also has plans for a 30-storey, sun-grown tower for downtown Vancouver.
Meanwhile, C.F. Møller has proposed a 34-storey wooden building for Stockholm, which would overtake Forte as the world’s tallest. The firm said the wooden structure will be built around stabilising concrete cores while pillars and beams will be constructed using solid wood and inside the apartments all windows, windows frames and ceilings would be made from wood.
Along with the actual increased building of these wooden structures, Green has noticed a building code evolution that is slowly addressing new materials and opportunities for architects. Earlier this year, the White House threw it support behind wooden buildings, announcing a climate-driven initiative that would see architects, builders and engineers trained in the benefits of wood as a structural material.
“Wood may be one of the world’s oldest building materials, but it is now also one of the most advanced,” said US Agriculture Secretary Tom Vilsack at the time. “Building stronger markets for innovative new wood products supports sustainable forestry, helps buffer reduce greenhouse gas emissions, and puts rural America at the forefront of an emerging industry.”
Green, who refers to wooden buildings as “incredibly safe,” said concerns over fire suppression are overstated with wood buildings.
“Even in the forest, if a fire goes through, the big trees stay standing, they char on the outside, the inside remains alive and those trees very often continue to grow for centuries especially here in the Pacific north west,” he says.
“It’s the same way we look at these buildings, they’re resistant and they last.”