Anthony Flint looks at the reasons why Vancouver-based architect Michael Green proposes "using wood to erect urban skyscrapers and multifamily structures of up to 30 stories," which was the subject of a recent TED Talk.
"For one thing, Green argues, using wood in a more systematic way would be good for sustainability," notes Flint. "Buildings account for nearly 50 percent of all global greenhouse gas emissions. In the construction process, 3 percent of the world’s energy is used for making steel, and 5 percent for concrete."
"Wood grows by the power of the sun, and harvesting wood through sustainable forestry practices – enough wood for a 20-story building is grown every 13 minutes, he says – would also be a form of sequestration of carbon, which is otherwise released when a tree falls and decomposes."
So why hasn't high-rise wood construction taken off? "The vast majority of city building codes, largely based on the tragedies of a century ago, limit the height of wood buildings, often to a mere four stories," explains Flint. However, the type of wood that would be used in high-rise construction - super-compressed mass timber panels - is "actually difficult to burn."
"Sweden has already approved a 30-story wood tower, and Vancouver is reviewing Green’s proposal for a structure nearly as high," adds Flint. "His white paper, 'The Case for Tall Wood Buildings,' is available at the Wood Coalition website."