Up until the mind XIXth century most homes and buildings were made out of wood, a readily available and cheap material. However, like we all know wood is easily flammable and caused a myriad of issues, especially in urban environments. How many times were whole cities at risk of being whipped out by flames? Rome? London? Once concrete, steel, aluminium and glass buildings came into the picture though, wood was relocated to a more gentle position: furniture.
Most regulations around the world require wooden buildings to be no higher than four stories, but here comes Vancouver-based architect Michael Green into the picture with a novel, some would say feeble, idea: erecting tall buildings, as tall as 30 stories for instance, made out of wood. Before you usher the thought right out, let’s hear a bit what he’s got to say.
During Green’s 2013 TED talk, in which he lays out his plans and ideas, he boasts a rather idealistic approach – the Earth grows our food, the Earth should grow our homes too. Wait, what? How is cutting down trees for buildings ever sustainable? Well, Green argues that during the construction of buildings, 3 percent of the world’s energy is used for making steel, and 5 percent for concrete.
By growing wood in a controlled environment and harvesting it accordingly Green claims enough wood for a 20-story building would be grown every 13 minutes. Another point he makes, one which I agree with, concerns the millions of trees that wither, die and fall to the ground around the world each year due to climate change. The pine beetle, flourishing due to warmer temperatures, has already devastated millions of acres in the Intermountain West. When a tree falls and decomposes it releases its carbon, but preserved and treated wood used for buildings would sequestrate this carbon.
Still, how do you prevent wooden skyscrapers from catching on fire from crying out loud? Green’s design is based on super-compressed mass timber panels, like Lego assemblies. This highly dense wood is extremely difficult to catch on fire (think of a huge tree stump on a fire), and coupled with coating solutions and modern anti-fire solutions, even simple sprinklers, would make these said wooden skyscrapers safe. Safety isn’t Green’s most convincing argument for bringing wood back into fashion in the constructions world, far from it – it’s necessity. An estimated 3 billion people are expected to flock to the cities in the coming decades, people that need cheap, reliable shelter.
In Sweden, a 30-story building completely made out of wood has already been approved, while Vancouver is reviewing Green’s proposal for a structure nearly as high. Read Green’s pitch on the subject at the Wood Coalition website.