Building code changes in the U.S. mark significant progress for the mass timber industry.
By Hardy Wentzel
Historically, the U.S. construction industry has been slower to embrace mass timber buildings compared with its Canadian and European counterparts — primarily due to the nation’s more complex code restrictions. But during the last few months, several events have indicated a long-awaited transformation of the industry toward a future that is more welcoming of alternative construction materials that simultaneously better the industry, and the wellbeing of the environment.
On Dec. 19, 2018, it was announced that all 14 mass timber code change proposals put forward at an International Code Council (ICC) public comment hearing in Richmond, Va., are expected to be approved. If approved, the proposals will be added to the 2021 International Building Code (IBC), which is slated for release in late 2020 — along with the full set of 2021 I-codes.
Together, the 14 proposals will create the following three new types of construction, all of which have had their fire and safety performances verified:
- Type IV A: Up to 18 stories high (270 feet tall) — mass timber is fully protected with noncombustible materials.
- Type IV B: Up to 12 stories high (180 feet tall) — allowable amount of exposed mass timber elements is limited.
- Type IV C: Up to 9 stories high (85 feet tall) — mass timber is allowed to be unprotected.
The code development cycle will continue throughout 2019, as well as any considerations for additional structural requirements for tall mass timber buildings.
The public hearing in Virginia follows in the state of Oregon’s footsteps. As of August 2018, Oregon became the first state to permit construction of mass timber buildings exceeding six stories. The new Oregon building codes also classify mass timber according to the three categories mentioned above.
Meanwhile in the state of Washington, proposal changes to the ICC Tall Wood Buildings Code were unanimously passed on Nov. 30. The state’s approved code changes permit construction of mass timber buildings of up to 18 stories, will be added to the IBC, and will go into effect in the second quarter of 2019. With that said, local jurisdictions are not mandated to adopt the changes and can opt out if they prefer.
Mass timber has a proven track record as a safe, fast, and sustainable construction solution with positive implications for development. In fact, its origins date back many centuries, and mass timber has outperformed endurance and longevity tests in the face of fire, weather, and seismic activity.
As a strong proponent of mass timber wood structures, I believe in the material’s potential to become the industry benchmark against which other construction materials are measured. Over the years, Structurlam has developed an extensive portfolio that showcases exactly how mass timber is changing the way we build. Two prime examples of the power of mass timber include Carbon 12 and University of British Columbia’s (UBC) Brock Commons – Tall Wood House.
Carbon 12 (www.structurlam.com/portfolio/project/carbon12) is exemplary of an environmentally advanced and technologically sophisticated residential project in the United States. A beautiful glass and timber showpiece located in Portland, Ore., the state-of-the-art eight-story wood structure serves as a model and precedent for timber construction across the nation.
The wood fiber used in construction of Carbon 12 was carefully sourced from the forests of British Columbia and fabricated at Structurlam’s southern British Columbia manufacturing facilities. By nature of the material, mass timber wood encompasses environmentally friendly qualities — namely carbon sequestering, which describes the process of offsetting carbon dioxide in the atmosphere through extraction and long-term storage in the material itself. Mass timber is also lighter in weight compared with other construction materials, such as concrete, and much faster and safer to assemble than any other structural system. In fact, the structure above ground was completed in eight weeks, despite construction taking place during Portland’s wettest winter on record.
Carbon 12 is comprised of 234 prefabricated Structurlam GlulamPlus beams, 336 GlulamPlus columns, and 242 CrossLam CLT panels. As a structural entity, the residential building also incorporates many sustainable and contextually responsive features, including an underground mechanical parking system, rooftop solar panels, and advanced earthquake monitoring and alert systems.
UBC Brock Commons
UBC Brock Commons (www.structurlam.com/portfolio/project/ubc-brock-commons), another innovative tall wood project in Structurlam’s portfolio, is an 18-story landmark and residence to 404 students on UBC’s Vancouver campus, and also happens to be one of the tallest contemporary mass timber hybrid structures of its kind.
Further to the ease of assembling mass timber structures, the Brock Commons building reached structural completion in record time — 66 days, or roughly four months ahead of schedule. In preparation for the build, the structure’s mass timber components were prefabricated locally at Structurlam’s southern British Columbia manufacturing facilities. Having pre-cut the materials into the quantities and configurations in which they were needed to be installed meant that the construction process could be expedited significantly. The Brock Commons project demonstrates the potential of mass timber as a reliable and durable construction material and the innovative design potential for the material.
The recent ICC announcements are encouraging, as are the exciting industry developments that are expected to follow in 2019. The building code changes observed in Oregon and Washington mark continued progress for the United States’ mass timber industry and promising implications to come in the future.
Hardy Wentzel is CEO, Structurlam Mass Timber Corp. (www.structurlam.com).