The Mass Timber Comparative Life Cycle Assessment Series endeavored to explore and answer the questions: How does mass timber compare to traditional structural systems? Is mass timber sustainable? What are the associated dollar cost premiums?

The series is a compilation of four comparative building studies based on reference mass timber buildings in the U.S. The reference buildings are compared to functionally equivalent concrete and/or steel building systems in terms of embodied carbon, using whole building life cycle assessment (WBLCA), dollar cost, and speed of construction. Each study details the building’s background, alternative designs, scope, and analysis results.

This report summarizes the individual study results and trends across the series. Because the series is limited to a few buildings in specific locations, the trends cannot be generalized to all buildings; however, broad conclusions and insights are feasible.

Overall, the building studies and trends demonstrate the effectiveness of mass timber systems as an embodied carbon reduction strategy across a range of building sizes, uses, construction types, and framing schemes, with speed of construction benefits and relatively low to zero whole building construction cost premiums.

For more information, see the series introduction and individual building studies:

• Mass Timber Comparative Life Cycle Assessment Series Introduction
• Return to From
• Nez Perce-Clearwater National Forest Supervisor’s Office
• Burwell Center for Career Achievement
• Denver Office

Authors:

This series was developed collaboratively by KL&A Engineers & Builders / KL&A Team Carbon and WoodWorks with funding from the USDA U.S. Forest Service and the Softwood Lumber Board.

Photos (top of page, clockwise from top left): Return to Form, Katz Development, tres birds, KL&A Engineers & Builders; Nez Perce-Clearwater Office, Mosaic Architecture, Morrison-Maierle, photo Heidi Long, Longview Studios; Denver Office, Shears Adkins Rockmore; Burwell Center for Career Achievement, Lake|Flato Architects, Shears Adkins Rockmore, photo Frank Ooms