Thornton Tomasetti Here's How: Mainstreaming Mass Timber

Mass timber is engineered wood – types include cross-laminated timber (CLT), dowel-laminated timber (DLT), glue-laminated timber (glulam), and nail-laminated timber (NLT) – that can replace steel or concrete as a structural system. It is prefabricated off-site and assembled on-site, enabling faster construction but requiring tighter coordination and different approaches to connections and performance.

Mass timber can reduce embodied carbon and shorten construction schedules. It also offers aesthetic and biophilic experiential benefits that can enhance building value.

Prescriptive provisions for mass timber fire safety have been added to codes in recent years. For buildings that fall outside the height or occupancy limits of current codes, performance-based fire design models fire scenarios to demonstrate safety.

Mass timber can be used for a wide variety of structures. Most common are office buildings to high- and low-rise residential, academic buildings and dorms, and cultural and arts centers. Advances in analysis and design are enabling mass timber to be used in laboratories and healthcare facilities, data centers, sports and recreation venues, bridges and transportation infrastructure, and aviation facilities.

Mass timber is a renewable resource that stores biogenic carbon and requires less energy to produce than steel or concrete. While its overall impact depends on forest management, sourcing, and transportation, mass timber is lighter than traditional materials. Buildings with mass timber structures thus can have smaller foundation systems, which use less material, further reducing total embodied carbon.