Now that the International Building Code allows mass timber construction up to 18 stories, developers and architects in many U.S. jurisdictions are increasingly engaging consultants like Buro Happold to investigate incorporating engineered wood materials like cross-laminated timber (CLT) and glue-laminated timber (glulam). Julie Janiski, partner, and Paul Richardson, principal, both with the Boston office of global consultancy Buro Happold, are valuable and authoritative sources for trends and applications of this leading-edge sustainability strategy.
According to Richardson, “The ability to use mass timber in larger scale developments provides further means for structural engineers to reduce the embodied carbon of new buildings, and provides a viable structural framing material alternative that can be used for most projects.”
He adds, “Whether used as the primary framing material or combined with steel and concrete in hybrid-framed structures, mass timber is a great way to reduce embodied carbon.”
According to Janiski, sustainability remains a major driver in the building sector, especially for companies and institutions with large facilities portfolios — and public commitments to reduce their environmental impact. “Mass timber structures represent an opportunity to build new facilities while meeting carbon reduction goals,” says Janiski. “A major benefit for the environment is that the wood components of CLT and glulam represent captured carbon, where the production of concrete and steel results in net-positive atmospheric carbon output.”
Richardson adds, “The technology is improving rapidly as more project teams employ it. Buro Happold is proud to partner with architects and their clients to explore the outer limits of what mass timber can do.”
A few examples of Buro Happold’s recent work featuring mass timber construction follow below:
Kean University Highlands Campus. This new Highlands Campus project includes an elevated forest canopy walkaway that connects the buildings for access and a unique experience of this special forest ecosystem. The structural design, in keeping with the project’s environment and sustainability goals, uses mass timber construction. Construction of the canopy walkway, which is approximately 1,000 feet long and extends 50 feet above the forest floor, uses a timber deck atop a glulam timber and steel frame, which is supported by a series of glulam timber columns. The walkway also connects to a 3-story treehouse that provides bleacher style seating for students.
201 Hamden. This mixed-use development in the Roxbury neighborhood of Boston will likely be the city’s first building with a structural system entirely composed of CLT. The Model-C system employed by partnering design firms Generate and Placetailor consists of a “kit of parts” which will be used in this case to produce a five-story structure with 14 residential units and ground-floor commercial space. Buro Happold’s structural engineering expertise is helping the designers and developers to realize another first as well: Boston’s first Passive House-certified structure.
Quinnipiac University, Recreation and Wellness Center. This new multi-purpose facility will make health and wellness a campus focus with expanded recreational space, an upgraded health center, a counseling center, a dedicated athletic training space for club sports, and four fitness studios. Teamed with designLAB architects, Buro Happold is providing integrated engineering services for the project, which will feature CLT floor slab within a steel frame.
Crystal Bridges Museum of American Art. Opened in 2011, this museum consists of eight interrelated pavilions that overlook and span across two man-made ponds on 120 acres of forested park. For the hanging roof, steel and glulam provide the lightweight structural components. To realize the suspended structures never before seen in a US museum, Buro Happold used post-tensioned concrete abutments to securely anchor the cables supporting the floating roofs.
The firm has also recently consulted with Generate and other partners in the Northeast to develop a catalog of systems dubbed Tallhouse, with the goal of making mass timber construction more easily adoptable by investors and designers. “The goal for the Tallhouse project is to help teams take advantage of the currently allowable limit of 18 stories for mass timber buildings,” says Richardson.