Last month we saw cross-laminated timbers installed at the Albina Yard project in Portland. It was the first use of U.S.-produced CLT in a building-wide structural system.
The first level of CLT (4,000 square feet) on Albina Yard went up in fewer than four hours. Last week, the second level was installed by a crew of seven in under two hours. Pretty remarkable, considering the contractor says it would have taken at least twice as many people two days or more to frame the same amount of floor space using traditional methods. Albina Yard is a four-story, 16,000-square-foot creative office project in north Portland. Besides its snazzy design by LEVER Architecture, the project is most notable for being tangible evidence that the U.S. CLT industry is officially off the ground.
There’s been a lot of buzz around CLT and mass timber in general over the past several months in Oregon and around the country — and rightly so. Besides drastically improved speed of construction (and the savings that go with that), mass timber offers significant environmental benefits. This includes tremendous carbon-storing capacity. Half the dry weight of wood is carbon. It got there when the trees were growing and absorbing carbon dioxide from the atmosphere. That carbon remains locked up for as long as the wood remains in use (a nine-story wood structure in China is now 959 years old—nearly a millennium). The new trees planted to replace those that were harvested start the carbon cycle all over again.
According to a quick, back-of-the-napkin calculation, Albina Yard, which is small by commercial construction standards, stores about 80.5 metric tons of carbon. That’s equivalent to offsetting 295 metric tons of CO2 emissions.
A larger Portland mass timber building, Clay Creative (60,000 square feet), stores more than 1 million pounds of carbon. Its total of 457.5 metric tons offsets 1,678 metric tons of CO2 emissions. “An additional 3,574 metric tons of CO2 emissions were avoided by using wood rather than concrete and steel,” says Dr. Jim Bowyer, an expert on the subject at Dovetail Partners, Inc.
From the Oregon Forest Resources Institute: https://oregonforests.org/blog/mass-timber-rising