About Taller Wood
Like in other parts of the world, we are seeing an increasing number of taller wood buildings across North America, signalling a new generation of architectural design and construction practices.
The Government of Canada’s Green Construction through Wood (GCWood) Program is encouraging innovative use of wood in buildings 10 storeys and over through funding of incremental research and development activities required to design, approve and construct tall wood buildings. Through the previous Tall Wood Building Demonstration Initiative initiated in 2013, the Government of Canada funded two successful demonstration projects: The Origine building in Quebec (the tallest all-wood condominium building in North America in 2017, at 13 storeys) and the Brock Commons Tallwood House student residence on the UBC campus (formerly tallest hybrid wood building in the world in 2017, at 18 storeys). The Government of Canada continues to build on the success of the previous demonstration projects by investing in new initiatives to fund additional demonstration projects including tall wood buildings, low-rise non-residential wood construction and timber bridges.
Carbon 12 in Portland – an 8-storey mass timber condo with ground floor retail highlights modern luxury, sustainable design and state-of-the-art technology, while the 7-storey T3 in Minneapolis – houses high-tech companies such as Amazon.
As new technologies, mass timber products and hybrid wood systems now offer innovative solutions for taller buildings, timber has become a recognized structural material by the Council on Tall Buildings and Urban Habitat (CTBUH) and their CTBUH Height Criteria– the official guidelines upon which tall buildings are measured.
Why Are We Building Taller with Wood?
- Efficient footprints. Wood structural systems have high building-volume-to-surface-area ratios, allowing for spacious interiors even with space constraints that typically require tall, compact designs.
- Tight envelopes. Mass timber components are fabricated with high levels of precision to ensure a tight fit. Together with wood’s natural insulating properties, mass timber construction offers strong thermal performance, which is critical for tall buildings.
- Proven fire resistance. Large wood slabs char on the outside, protecting their inner structure, which is essential to occupant and first-responder safety in wood buildings, particularly those with multiple stories, during a fire event.
- Structural and seismic performance. Wood’s strength-to-weight ratio is competitive with steel, but it weighs considerably less, reducing the load on the foundation during seismic events and making for a resilient and safe structure.
- Faster and safer on-site construction. Prefabricated sections can be manufactured off-site, shipped to the project and then assembled on site, significantly shortening project timelines and improving safety and accuracy.
The case for tall timber is also driven, in part, by their significant environmental benefits. As we confront the fact that buildings are one of our greatest consumers of energy and resources, wood offers a solution that literally grows on trees. While concrete emits nearly its own weight in carbon dioxide, responsibly harvested timber is naturally renewable, recyclable and locks in carbon for the life of the building.
Over the past several years, a number of tall wood projects have been completed around the world, demonstrating successful applications of new wood and mass timber technologies. FII and the Binational Softwood Lumber Council engaged Perkins + Will to look at ten international tall wood buildings, and presents some common lessons learned from the experiences of various stakeholders, including the Developer/Owner, Design Team, Authorities Having Jurisdiction (AHJ), and Construction Team for each project. Download the Tall Wood Survey Report With Bulletins here.
Are Tall Wood Buildings Safe?
In recent decades, mass timber’s capabilities have rapidly expanded with the resurgence of past technologies, such as nail-laminated timber and Glue-Laminated timber and the introduction of new products, such as cross-laminated timber, dowel-laminated timber, laminated strand and veneer lumber and more recently mass plywood panels.
In response to growing support for taller timber structures throughout the United States, the International Code Council approved 14 changes to the international building code (IBC) in early 2019, permitting mass timber construction up to 270 feet (~80 metres). Similarly, Canada is also making changes to its building code, opening up new opportunities for taller wood designs.
Not only can mass timber deliver the strength and durability necessary for taller structures, it also offers fire safety. Robust real-life fire testing underpins the recent changes to the International Building Code that will permit timber buildings up to 18 stories tall.
What Is Next for Tall Wood Construction?
North America policymakers and industry have responded to the evidence that mass timber can stand tall.
- Backed by expert opinions and testing, the IBC will introduce a new building code in 2021 that will help streamline and standardize tall wood construction.
- Oregon modified its building code in 2018 to permit tall building construction up to 18 stories.
- Washington state has taken a similar step and it will be effective in Spring of 2019.
- As of Spring 2019, British Columbia will be the first Canadian province to allow timber construction up to 12 stories.
In the coming years, expect measures to be taken at state levels to harmonize regional building codes with new building types that accommodate mass timber. With rising demand for new urban buildings, growing North American infrastructure for mass timber production and increased interest in sustainable and efficient construction, the potential for taller wood buildings is expected to grow.