As the race heats up to demonstrate that timber is a viable alternative to concrete for mid and high-rise buildings, Portland, Oregon, has been leading the way in realizing mass timber projects. The latest to claim the country’s tallest timber building crown is Carbon12, an 85-foot tall mixed-use building in Portland, designed by PATH Architecture.
Built with a mix of glulam beams and cross-laminated timber (CLT) surrounding a central steel core, the eight-story building was designed to have a minimal environmental impact and promote Oregon’s local timber industry. As downtown Portland addresses a growing demand for housing, timber projects constructed with prefabricated CLT panels cut off-site, like Carbon12, hold a speed advantage over traditional steel and concrete techniques.
Carbon12 features a mix of 14 residential units, each with their own recessed balcony, as well as retail on the ground floor and a mechanized underground parking system. While the exterior is clad in vertically striated metal paneling that recalls timber grain, PATH chose to accentuate the natural materials of the interior spaces by leaving the wood columns, beams, and undersides of the CLT slabs exposed for a warmer feel.Every unit features a recessed balcony, with two units per floor. (Courtesy PATH Architecture)
PATH’s focus on sustainability as a requirement in part drove their decision to use timber for Carbon12. Because locally grown timber can sequester more carbon dioxide than is used to grow and transport the wood, it often has a smaller carbon footprint in production than steel or concrete. Carbon12 will also feature solar panels on the roof.
Although Carbon12 is currently the tallest timber building in the U.S., it won’t be for long. The 148-foot tall, 12-story Framework building, also in Portland, is shooting to take the title once it finishes in winter of 2018. Designed by LEVER Architecture and the Framework Project, Framework will feature a wood core as opposed to steel. Still, as timber buildings continue to push higher and higher, they may be paving the way for the eventual acceptance of timber as a mainstream urban construction material.
Carbon12 is now fully complete and units are available on the market.