Arlington Operations Center, mass timber focus

The Arlington Operations Center represents a bold step forward for public works facilities in the Pacific Northwest — proving that functional, workhorse buildings don't have to sacrifice innovation or sustainability. Delivered through a Progressive Design-Build process, Cornerstone partnered with Dykeman Architects from the earliest planning stages to give Snohomish County Public Works a facility that is built to perform for decades to come.

At the core of this two-story, 18,000-GSF facility is a hybrid structural system that pairs mass timber with steel and concrete — balancing warmth, efficiency and durability in an environment designed for the demands of a busy public works operation. Three-ply cross-laminated timber (CLT) panels, serve as the floor and roof decking throughout, supported by a post-and-beam framework of glulam beams, steel columns and a concrete foundation. The result is an exposed structural aesthetic that communicates craftsmanship and permanence without sacrificing the rugged utility the building demands.

Cornerstone self-performed the mass timber installation alongside a specialty erector coordinating panel sequencing, connection detailing and moisture protection from the ground up. Close collaboration with the structural engineer allowed the team to optimize the hybrid framing layout during preconstruction, resolving complex beam-to-column connections and CLT panel strut conditions before a single panel was lifted into place.

Project Highlights:

• Progressive Design-Build delivery — Cornerstone and Dykeman co-developed the structural concept and budget in real time with the owner
• Hybrid mass timber structure featuring 3-ply CLT floors and roof, glulam post-and-beam framing, structural steel and concrete
• Early collaboration with the structural engineer to resolve connection details and optimize framing geometry prior to fabrication
• Exposed CLT and glulam throughout create a biophilic, high-character interior befitting a forward-thinking public agency
• Snohomish County Public Works' first mass timber facility