Wood is cheaper and more energy-efficient than steel. Should we be using it to build skyscrapers?
Since the invention and development of steel and concrete, the combination of which would spawn the birth of the skyscraper, wood as a building material has been marginalized as simple construction ephemera, used to form concrete or to structure building frames advanced with the expressed purpose of producing single family homes or large estates and to furnishing their plush interiors.
Wood fell out of vogue in a large part because of its vulnerability to fire, probably the single greatest factor in restricting use of the material to smaller structures. But change is coming, writes CNN, as wood has become transformed by a handful of dedicated engineers and architects – Shigeru Ban most notable among them - and put to use in the service of large-scale structures like Michael Green‘s proposed “Tallwood” skyscraper in Vancouver.
Photo courtesy of Michael Green
The plans for the 30-story tower are among a small group of “woodscrapers” being proposed throughout the world, which all had to overcome stringent building codes. Explaining the motivation behind his design, Green says that wood construction at such scales is decidedly cheaper than standard-industry methods and, more importantly, much more energy efficient, given the large amounts of CO2 expended in the manufacturing of steel and concrete and the extent of their large carbon footprints. Conversely, wood traps carbon dioxide throughout a building’s life cycle, and, if sustainably harvested from controlled and well-managed forests, can prove to be a renewable resource.
For Tallwood, Green has created a system of laminated strand lumber beams which are load-bearing and fire-resistant. Where the structural capacity of steel rapidly degrades when exposed to flames, the large beams, which are comprised of strips of wood fibers glued together, develop an exterior layer of char that insulates the wood’s structural core. Innovative designs such as Tallwood, when coupled with may propel wood at the forefront of future construction advancements.
As Green says, “Really we’re at the stage where we’re able to start to show what’s possible, a bit like that Eiffel Tower moment. That was built when no one was used or understood tall structures, but it showed what could be done and just as importantly stretched the imagination.”
This post originally appeared on Architizer, an Atlantic partner site.