Asa Mercer Middle School, mass timber

Standing prominently on Beacon Hill, the newly expanded Asa Mercer International Middle School is redefining sustainable school design — over 95% of the primary structure is comprised of wood, maximizing the benefits of mass timber. Bassetti Architects designed the school to both modernize the campus and to enhance its visibility and accessibility because it serves as both an educational institution and a gathering space for Beacon Hill-area residents.

At the heart of the expansion is a three-story, mass timber classroom wing, setting a new standard for sustainable and student-centered learning environments. Connected by a striking “Spine”, which runs north to south, the project seamlessly links the classroom wing with the rest of the school. This spine, constructed entirely of mass timber, serves as both a functional and architectural centerpiece, reinforcing the school’s commitment to innovative, environmentally conscious design.

A defining feature of the Spine is its V-shaped glulam columns, which create a bold and dynamic aesthetic while providing essential structural support. These 86 exposed sloped columns, anchored with rod and clevis connections, suspend the second floor cross-laminated timber (CLT) deck, demonstrating both engineering precision and craftsmanship. Across the project, mass timber is used on an impressive scale, with over 300 CLT panels and 1,000 glulam beams integrated into the structure.

By embracing mass timber at this scale, the project not only reduces its carbon footprint but also creates a warm, natural and inspiring environment for students and educators. As it welcomes the next generation, Asa Mercer stands as a beacon of innovation — a school built not just for today, but for the future of education in Seattle.

Project Highlights:

• Engineered innovative shoulder-bearing column connections that eliminated steel components while increasing timber sizes, keeping the architectural vision within budget

• Developed custom erection sequences and connection details for complex sloped column geometry along the 500-foot central spine

• Performed cost studies between wood species to balance cost and performance requirements

• Applied cumulative lessons learned on temporary bracing, wet weather protection and connection methods