slide show on one of my favourite subjects: plyscrapers.
There's a growing trend of constructing larger buildings from wood, instead of the much more common concrete and steel. The environmental impact of concrete is significant; it's estimated that 5% of global carbon emissions are from the cement industry alone.
New technologies, such as cross-laminated timber, allow sustainably grown wood to be made into building elements suitable for tall buildings. The wood used in a 20 story building would capture about 3000 tons of carbon. In contrast, a typical concrete structure would expend around 1300 tons. That's a big swing!
Such tall building has so far been outside of the USA. The Guardian has a great report on big timber structures going up in Canada and New Zealand, for example.
Sweden is also involved, of course. Radio Sweden recently covered the growth in tall timber construction. PM Stefan Löfven visited wood apartment buildings in Sundbyberg just last week. A quarter of all new construction in the city of Växjö is in timber, with the intent to double that in five years. The fact almost all of the wood used comes from sustainable Swedish forests is a bonus.
Things are moving in America, too. The US Government has announced a Tall Wood Building Competition. The time for submissions has recently closed, and winners will be announced in the coming months. I'll be sure to report back here on the contest.