Over on The Mark, two men I know and admire debate the merits of wood construction. Larry Richards of the John H. Daniels Faculty of Architecture, Landscape, and Design, University of Toronto (my alma mater) writes:
Towers made of timber could herald a new environmentally friendly era of construction.
In architecture, engineering, and forestry sectors around the world, there is a mega-buzz about forthcoming high-rise towers made of wood. Imagine a 20, 30, or even 40-storey condominium or office tower that has timber structural-members and is clad in wood.
But Avi Friedman, Architect; Director and Professor, McGill School of Architecture, says: Not so fast.
A Question of Safety - and Courage
Innovation is good, but it needs to be tested.
When you talk about it from an environmental point of view, wood skyscrapers are a great idea. After all, these structures are made using renewable material. However, it all boils down to a question of safety. It is commonly known that wood-constructed buildings can withstand earthquakes better than those made of steel or concrete. But there is still much concern around the issue of fire.
Friedman notes that wood is better than steel, which softens at high temperature. But he doesn't mention any of the testing that has been done in Europe with cross-laminated timber, (CLT) where they not only found that it lasted longer than steel, but that as it burned, the layer of black char that formed was actually an insulator. They have done the testing and figured out how much thicker a panel has to be structurally sound after a layer has been converted to char. I think perhaps that Avi is being a bit too conservative.
More on Wood Construction:
Nine Storey Apartment Built Of Wood in Nine Weeks By Four Workers
Wood Construction Scales Up
Wood Construction Goes Seriously Vertical. But Does it Really Sequester Carbon?
More on Avi Friedman:
Adam Vaughan Steals Show at Ontario Heritage Conference
Room For Thought: Essays by Avi Friedman