How can more sustainable cities be created in order to meet the needed carbon reduction goals in the face of a 30 percent world population growth over the next 30 years, when the construction industry already generates 49 percent of Carbon Dioxide emissions? Mass timber systems—and tall wood buildings in particular—are an important part of the urban solution.
Unique insights on the growing use of mass timber in the United States are provided, beginning with a brief overview of the attributes that make wood a sustainable choice, including renewability, carbon sequestration, low embodied energy, and the potential positive impacts on forest health. Discussion shifts to buildings, including international projects that have pushed beyond perceived height limitations for the past three decades, and government policies that have supported their construction.
Shifting to the US, the unique characteristics of mass timber products are introduced—such as cross-laminated timber (CLT), nail-laminated timber (NLT), and glue-laminated timber (glulam)—that enable them to meet safety and performance requirements for tall wood buildings, and changes approved for the 2021 International Building Code that are allowing wood buildings up to 18 stories. The current state of mass timber in the US is then reviewed and summarized, including the key market drivers for early adopters of the techniques and technology.