Princeton University Briger Hall, Commons, and School of Engineering & Applied Sciences
The Princeton University Briger Hall, Commons, and School of Engineering and Applied Science (SEAS) buildings form the core of a new academic neighborhood on campus. These state-of-the-art facilities replace outdated infrastructure with a cohesive, sustainable environment for research and teaching. StructureCraft served as the timber design-assist partner and builder for the mass timber superstructure, delivering engineering, fabrication, and installation services for this significant expansion.
Structural System and Design
The superstructure for the Briger Hall and SEAS buildings is defined by a refined Glulam post and beam framework supporting Acoustic Dowel-Laminated Timber (DLT) floor and roof panels. A standout feature of the design is the unique connection detailing: Glulam beams are "necked down" at the ends to fork into the columns, allowing for direct timber-to-timber bearing. This elegant detailing minimizes visible steel hardware, creating a warm, clean aesthetic that aligns with the architectural vision while achieving the required 2-hr FRR. Large open atrium spaces include feature stairs with cranked steel stringers suspended from the Glulam frame.
Construction Challenges and Innovation
Constructing these expansive academic facilities required precise coordination to integrate complex laboratory and teaching requirements within an exposed timber structure. The "kit-of-parts" fabrication strategy allowed for rapid assembly of the post, beam, and panel components across the large footprint. The use of DLT panels provided an integrated acoustic solution directly in the structural decking, eliminating the need for secondary ceiling treatments and allowing for a seamless integration of MEP services.
Sustainability
As part of one of the first all-electric science complexes of its kind, the Briger Hall & SEAS buildings prioritize low embodied carbon through their extensive use of mass timber. By substituting traditional steel and concrete with sustainably sourced timber, the project significantly reduces its carbon footprint while providing a biophilic environment that connects researchers and students to nature.
Princeton Commons
The Princeton Commons serves as the vibrant social heart and connector for the new ES & SEAS neighborhood. Designed to foster collaboration and gathering, the building stands out as a focal point within the precinct, linking the surrounding academic structures. StructureCraft provided the structural engineering and construction of the building's highly complex hybrid timber roof and floor diagrid structure.
Structural System and Design
The defining structural element of the Commons is a sophisticated two-way hybrid timber-steel diagrid that forms the structure for the third floor and roof. This diagrid supports Acoustic Dowel-Laminated Timber (DLT) panels, creating a striking, exposed geometric ceiling that spans the open gathering spaces below. The hybrid system leverages the stiffness of steel nodes with the beauty and carbon benefits of timber members to achieve long spans and a dramatic architectural form. Chaseways were integrated between the hybrid Glulam/steel assemblies to facilitate MEPF routing throughout the structural system.
Construction Challenges and Innovation
The Commons presented unique geometric and fabrication challenges due to its hybrid diagrid structure. Achieving the seamless interface between the steel nodes and timber diagonal members required exceptionally tight manufacturing tolerances and VDC coordination. Two-way spans of up to 60' were achieved with Glulam and steel flitch plate assemblies, which were shop-assembled and erected as a kit-of-parts onsite.
StructureCraft balanced detailing for the tight-fit connection requirements necessary to ensure composite action between the timber and steel components, construction tolerances, concealment of all connections, and design for a 1-hr FRR. The installation involved a complex erection sequence to ensure stability and fit-up of the diagrid elements, showcasing the successful integration of dissimilar materials into a unified, high-performance structural system. An innovative erection approach involved lifting the long diagrid assemblies into place from below their final condition instead of from above, which greatly simplified the installation process and enabled tighter fabrication & assembly tolerances.