New Interactive Resource Can Assist Engineered Design of CLT Systems

The inclusion of a built-in database of CLT layups reduces manual inputs, increasing speed and accuracy of calculation reports.

A new set of free-to-use design tools released by engineering consulting firm EQUILIBRIUM will greatly improve the speed and accuracy of engineering the design of structural cross-laminated timber (CLT) systems. The CLT Structural Design Tools by EQUILIBRIUM was developed in part with funding from the USDA Forest Service Wood Innovations Grants and the Softwood Lumber Board to support the work of the mass timber design community.

CLT Structural Design Tools is an Excel-based resource that can be used for the engineered design of CLT panels for a wide range of applications such as roofs, floors, and walls. The toolset contains a built-in database of all PRG 320-certified CLT layups currently available in the marketplace, allowing the user to quickly input predefined layups using macros or via manual input. Once the layup and user-provided information such as loading are supplied, the toolset automatically performs calculations and design checks. The tools also verify relevant design criteria such as strength (cold and fire) and serviceability (deflection and vibration). Designs can be performed quickly, and calculation reports are easily printed.

"CLT's use as a structural material in buildings is increasing exponentially, and for good reason," said Matt Kantner, PE, SE, Associate Principal at EQUILIBRIUM. "We wanted to create a set of tools for engineered design that keeps pace with the industry—that is reliable and takes the guesswork out of CLT design. It is straightforward, approachable, and transparent, which makes it a great for seasoned mass timber engineers and newcomers alike. A thank you to our sponsors and partners, including the USDA Forest Service and Softwood Lumber Board, who provided funding; Holmes, who performed a peer review; and all the CLT manufacturers who reviewed the database in the resource for accuracy of their CLT products." 

EQUILIBRIUM encourages the adoption of this toolset by structural engineering firms, material suppliers, architects, and others with an interest in CLT systems. EQUILIBRIUM pledges to support and update the resource for a minimum of two years to keep up with the rapidly evolving CLT marketplace. For questions and comments, please contact



EQUILIBRIUM is a structural engineering consulting firm globally recognized for its advanced timber engineering expertise, innovative structural designs, and architecturally focused approach. The firm was established in 1998 in Vancouver, BC, and now boasts additional offices in Atlanta and Paris. Please visit our website at to learn more about our team and our approach. 

About the Softwood Lumber Board

The Softwood Lumber Board (SLB) is an industry funded initiative established to promote the uses as well as the environmental and economic benefits of softwood lumber products. Programs and initiatives supported by the SLB, including the American Wood Council, Think Wood, and WoodWorks, focus on increasing the demand for lumber products in the United States. For more information, visit