Many major urban centres are experiencing a quiet revolution—the revolution of the skyline, and what a revolution it is, literally. Mass timber is a new mode of thinking about wood that has rapidly emerged as one of the most globally discussed building materials in contemporary architecture, urbanism, and timber construction. As mass timber experiences further growth in terms of sustainability, durability, and beauty, it will alter the way cities envision their futures.
Instead of being manufactured as lumber, mass timber is built as many pieces of wood glued together under pressure, such that the massive pieces of wood are so strong that the pieces can act like steel, but only to be fabricated into panels or beams. The finished pieces can also be strong enough to create multiple stories of buildings, and in fact, high-rises, which dispels the myth that wood can only be used for small buildings.
The key difference is not only how the material performs; mass timber also allows for the opportunity to reduce carbon emissions. Greenhouse gas emissions from buildings are one of the most significant contributors of greenhouse gases, as both steel and concrete have a considerable carbon footprint. However, mass timber allows carbon to be locked up for 50-100 years, and it also uses significantly less energy than conventional construction. For architects and cities steeped in the climate crisis, mass timber provides the opportunity to rethink the broader environmental footprint of building materials.
In North America and Europe, mass timber is gaining traction. Portland, Oregon, was one of the first cities in the U.S. to build a tower built from mass timber, while Norway built Mjøstårnet, an 18-storey timber tower, the tallest timber building in the world. Every mass timber project continually pushes the boundaries of codes, contractors, and public perceptions of building possibilities.
Mass timber is not only about its sustainability; it is about the experience. Exposed wood interiors, the acoustics of timber-frame spaces, and the mental health benefits of using natural materials are creating conditions that feel human. There are many mass timber offices, schools, and residential buildings where the occupants have reported well-being and satisfaction compared to what a typical building provides.
Still, it is not without challenges. The questions of fire safety, sourcing from sustainable forests, and the cost of construction all slow the development of mass timber, aside from simply evolving in use. Yet, we will likely see mass timber continue to grow, as cities and governments continue efforts to test codes and launch incentives to allow more use of mass timber.
Why does it matter: As cities continue to grapple with increasing demands to house and provide infrastructure for populations, mass timber represents a scalable and renewable resource that can produce infrastructure that builds taller, not smarter. If the 20th century was built on concrete and steel, the 21st century will be about how architects and engineers catalyze a reimagination of wood.
In the future, when mass timber becomes ingrained as the new normal for buildings, it may not only change how cities are constructed but also shift how we perceive our relationship with cities, forests, and materiality; wood as a timeless material for addressing the immediate needs of a rapidly urbanizing world.
