Oregon Becomes First State To Legalize Mass Timber High Rises

Thanks to a recent addendum to Oregon’s building code, the state is the first in the country to allow timber buildings to rise higher than six stories without special consideration.

Portland has become something of a hotbed for timber innovation as of late. Carbon12, PATH Architecture’s eight-story glulam and cross-laminated timber (CLT) tower with a steel core, recently became the country’s tallest timber building and was set to be surpassed by LEVER Architecture’s 12-story Framework. Alas, that project was put on hold due to mounting financial difficulties last month, but it seems the precedent that the project achieved in securing a building permit from the State of Oregon and City of Portland will live on.

The timber allowance comes courtesy of Oregon’s statewide alternate method (SAM), a state-specific program that allows for alternate building techniques to be used after an advisory council has approved the “technical and scientific facts of the proposed alternate method.” The allowance comes after the International Code Council (ICC)–the nonprofit group that Oregon models its building codes after–established the ICC Ad Hoc Committee on Tall Wood Buildings in 2015 to explore the benefits and challenges of using timber in tall buildings.

A Committee Action Hearing was held in April of this year, where the Ad Hoc Committee, made up of code experts, stakeholders, and industry members presented their findings. All 14 of the committee’s suggestions were adopted, introducing standards and best practices for fireproofing, the load-bearing potential of CLT and heavy timber, water resistance, sealing, seismic ratings, and more.

Three new building classifications were introduced as a result: Type IV A, timber buildings permitted up to 18 stories and 270 feet tall, Type IV B, timber buildings with a maximum height of 12 stories and 180 feet, and Type IV C, which is permitted to rise nine stories and 85 feet tall at maximum. The shortest of the timber typologies is allowed to use exposed structural timber as an interior finish, whereas the tallest, type A, must enclose all exposed surfaces and include a three-hour fire-resistance rating for the structural elements.

Read more on this from The Architects Newspaper at https://archpaper.com/2018/08/oregon-legalize-mass-timber-high-rises/.

Nation’s Largest Mass Timber Building Under Construction In Oregon

As a crane lowered a glulam beam and construction workers on either end deftly guided it into connection with two upright wooden columns, a tour group member shook his head and said, “It’s like Lincoln Logs.”

Kind of. Which may in part explain some of the attraction of builders and designers to the potential use of strong, precisely engineered, carbon-storing wood beams, columns, wall panels and floor decking. As Chris Evans, a Swinerton Builders project manager put it, wood is the first building material people use to make the forts, homes and hideouts of childhood.

These days, builders and designers are joining mill owners, university researchers and policy makers in taking a fresh look at advanced wood products, “mass timbers” and what’s come to be called “tall wood” design. Advocates believe it can replace concrete and steel in mid- to even high-rise buildings, and provide an economic jolt to rural Oregon in terms of forest management and mill jobs.

In Hillsboro, Evans and Swinerton Builders are overseeing construction of the largest known U.S. building to date that uses cross-laminated timber, or CLT, for flooring, and glulam posts and beams. The Oregon headquarters of First Tech Credit Union will be five stories high and have 156,000 square feet of office space. Swinerton Builders is the general contractor.

Another tall wood building planned for Portland, called Framework, will be 12 stories high and will have five floors of affordable housing. That project was awarded a $1.5 million federal design competition grant to help with seismic and fire testing and certification.

From Capital Press: https://www.capitalpress.com/Oregon/20171005/nations-largest-mass-timber-building-under-construction-in-oregon

America’s First Wood High-Rise Building To Debut In Oregon

Wood is a go-to material for floors, doors, furniture, and now, a skyscraper—the very first of its kind in the U.S. Construction on Portland, Oregon’s wood high-rise, Framework, is slated to begin this October. The 12-story mixed-use building—a collaboration between local firm Lever Architecture and real-estate developer Project—will be made primarily from timber. Thomas Robinson, Lever Architecture’s founder, says his company is interested in “exploring the relationship between materials, experience, and the environment—how the way we build impacts the way we live and the environment as a whole.”

To highlight the innovative design, the structure will be centered around a visible vertical core and capped with a roof deck framed by wood columns. Flexible, sturdy, and lighter than materials like concrete or steel, timber has a high strength-to-weight ratio. Framework’s design includes cross-laminated wood panels, engineered of stacked lumber, for floors and ceilings, and glue-laminated timber for beams and columns.

Inside, a double-height community space will feature a public exhibition documenting the building’s creation and impact, plus a second-floor garden terrace. Visitors will be able to roam retail spaces on the ground floor, while above there will be five floors of offices and five floors of affordable housing.

The “forest to frame” philosophy behind the building reflects its relationship between urban construction and rural lumber manufacturing. This project creates more opportunities in both industries, which were gravely affected in the recession. “Framework stands as a model for sustainable urban ecology,” says Robinson. And there are copious environmental benefits: Buildings made primarily of wood have significantly lower carbon emissions and use less energy than those made from traditional materials. Earlier this year, the U.S. Department of Agriculture took notice. It solicited designs for a tall wood building competition, and the Framework team won an impressive $1.5 million grant to fund further research and development—the structure is expected to be finished by December 2017.

From Architectural Digest: https://www.architecturaldigest.com/story/first-wood-highrise-building-portland