Permit Approved For Nation’s First All-Wood High-Rise In Oregon

Officials in Oregon have approved construction permits for the first all-wood high-rise building in the nation. Construction on the 12-story building, called Framework, will break ground this fall in Portland’s trendy and rapidly growing Pearl District and is expected to be completed by the following winter.

The decision by state and local authorities to allow construction comes after months of painstaking testing of the emerging technologies that will be used to build it, including a product called cross-laminated timber, or CLT.

To make CLT, lumber manufacturers align 2-by-4 boards in perpendicular layers and then glue them together like a giant sandwich before sliding the resulting panels into a massive press for drying. The resulting panels are stronger than traditional wood because of the cross-hatched layers; CLT can withstand horizontal and vertical pressures similar to those from a significant earthquake with minimal damage. They also are lighter and easier to work with than regular timber, resulting in lower cost and less waste.

For this project, scientists at Portland State University and Oregon State University subjected large panels of CLT to hundreds of thousands of pounds of pressure and experimented with different methods for joining them together. The project materials also underwent extensive fire safety testing and met fire codes.

State officials hope the building will stir greater interest in high-rise construction using mass timber and help revitalize the state’s lagging logging industry. Logging, once a major source of revenue in Oregon, has dropped sharply in the past few decades because of greater environmental protections for salmon and the spotted owl. The loss of the industry has devastated some of the state’s rural communities.

From The Register-Guard: https://registerguard.com/rg/news/local/35651365-75/portland-approves-permit-for-nations-first-all-wood-high-rise.html.csp

Mass Timber: From ‘What The Heck Is That?’ To ‘Wow!’

Mass timber is sprouting up in cities in North America and abroad. After years of feasibility studies and design proposals, buildings six stories or taller constructed primarily from pre-engineered wood products are being considered in cities around the world.

In London, one proposal, called the Splinter, would rise to 100 stories. In Chicago, Perkins+Will (in collaboration with Thornton Tomasetti and the University of Cambridge) has designed an 80-story high-rise with 300 duplex apartments. If built, River Beech—a key component of P+W’s master plan for the Riverline development—would be made almost entirely from mass timber.

So-called “plyscrapers” are still a tiny sliver of nonresidential construction. In the past five years, only 17 buildings seven stories or taller have been completed worldwide, mostly in Europe and Canada. Six more have started construction, according to the American Wood Council.

Mass production of timber for high-rise construction is still in its infancy in North America. Specifying these products in the U.S. faces resistance from insurers, regulators, and code officials. Steel fabricators and concrete suppliers disparage mass timber for taller buildings on the grounds of safety and durability.

Proponents cite the speed at which tall buildings can be constructed using pre-engineered wood and mass timber’s ability to sequester carbon. Joey-Michelle Hutchison, RA, LEED AP BD+C, CSBA, Associate Vice Principal, CallisonRTKL, says, “The role of mass wood is going to grow because of the demand for sustainable design.” Researchers from Yale and the University of Washington, in a study published in the Journal of Sustainable Forestry (March 28, 2014), postulated that using wood substitutes for constructing buildings (and bridges) could save 14–31% of global CO2 emissions.

From Building Design + Construction: https://www.bdcnetwork.com/mass-timber-what-heck-wow

Canadian Building Will Be The Tallest Timber Structure In The World

Vancouver-based real estate developer PortLiving and world-renowned Japanese architect Shigeru Ban have unveiled plans for an upcoming hybrid timber structure said to be the tallest in the world. If so, this would mean it will be higher than other CLT wood structures, such as the 34-story design planned for Stockholm.

The residential high-rise Terrace house, which will be located in Vancouver’s Coal Harbor neighborhood, may set a new standard for urban luxury in design, sustainability and engineering innovation. The high-rise will feature a cross-laminated timber frame supported by a concrete and steel core. Wood for the project will be locally sourced from British Columbia, minimizing its carbon footprint.

Cross-laminated timber has been gaining popularity as of late, due to its lightness, sustainability, and ease of use. Planks of timber are glued and orientated at 90 degrees to each other, and are then crosslaid in layers. Those pieces are then shipped to construction sites and can be assembled by just a few workers, even for large buildings.

Its use in tall wooden buildings has also been growing. London, Stockholm, and Quebec are just a few of the cities who either already have large timber towers or have one in the works. Recent plans include a Swedish firm’s 436 ft. residential wood skyscraper in Stockholm, while a 12-story mixed wood high-rise is planned for construction in Portland, Oregon.

Building codes are being adjusted in Oregon and Washington State to permit the tall wood structures. But CLT hasn’t gone without opposition.

From Woodworking Network: https://www.woodworkingnetwork.com/news/woodworking-industry-news/canadian-high-rise-will-be-tallest-timber-structure-world?ss=news,news,woodworking_industry_news,news,almanac_market_data,news