First California State University System Mass Timber Project is Underway

As Swinerton Project Executive Matt Beyer squints into the bright sunlight on a hot July day at Chico State, he sees a string of installed mass timber columns stretching across the foundation of the new $14 million University Service Building (USB). Shrink-wrapped mass timber beams are stacked nearby awaiting installation.

“It snaps together fast when you do the upfront coordination properly,” Beyer remarks.

The University, located about 100 miles northwest of Sacramento, is the first in the 23-campus California State University system to construct a building using mass timber. Swinerton began construction on the two-story, 24,0000-square-foot structure in May and it’s scheduled for completion in early 2025.

To Beyer’s point, mass timber orchestration begins months ahead of onsite installation.

In many instances, according to Swinerton Director of Mass Timber Lisa Podesto, the feasibility of utilizing mass timber is evaluated early in deciding the right structural grid and construction type to accommodate the project program. Things like fire rating, level of timber exposure and mechanical, electrical and plumbing (MEP) distribution are considered, and floor layouts are checked to make sure all columns can align between floors of a multistory building.

“Cantilevers and offsets aren’t always compatible with an efficient mass timber structure,” says Podesto. “We have to make sure the grid is optimized for mass timber.”

For example, while 30-feet by 30-feet is generally standard for an office grid, it’s not typically as cost-efficient for mass timber. A smaller, rectangular grid that maximizes the span of the mass timber panel and minimizes the number of timber support elements creates the best opportunity for material efficiency.

Also being considered is the species of wood to use, primarily for the desired look sought by the client and the strength needed by the engineer. However, options need to be identified in case the cost and accessibility of that species change before construction kick off.

“You need to build flexibility into the specifications,” Podesto said. “Sometimes there are shifts in the market affecting price and availability. Putting flexibility into the specification allows the general contractor or mass timber supplier to meet the project needs for the best price.”

Key contributors to the analysis and decision-making process are representatives of Timberlab, a Swinerton-affiliated company that fabricates glue-laminated (glulam) mass timber columns and beams and cross-laminated timber (CLT) panels at its Portland, OR, and Greenville, SC, facilities.

“Timberlab supports the design team in making good decisions about the use of mass timber on our projects,” Podesto said. “They come from a general contracting background, so they know how to integrate mass timber into construction. They make sure it’s highly constructible and cost-efficient, and that we minimize potential problems with it at the construction site.”

Timberlab acted as the material supplier, sourcing the glulam from a manufacturer in Eugene, OR, and the CLT panels from a maker in Columbia Falls, MT. They provided a fully coordinated and complete fabrication model for the CLT panels and glulam, accommodating all connections and penetrations for ductwork, electrical wiring, and piping. Timberlab also provided fabrication services for the glulam elements, cutting and shaping them on a computer numerical control (CNC) machine and preinstalling the hardware at its facility in Oregon. The finished timbers were then transported 500 miles from Portland to Chico.

Project Manager Collin Govan says once timber deliveries began arriving at Chico State, Swinerton self-perform installers used a packing list to check for details found in QR code stickers placed on each shrink-wrapped bundle. This ensures timber pieces arrive in the correct order with the installation sequencing plan. The shrink wrap is removed, and timbers are inspected to guarantee nothing has been damaged in transit. Installers follow a plan and pick each timber piece by crane directly from a truck and then “fly” it to the intended location where it’s installed onto the foundation. Next, all installation points are checked to make sure the correct hardware is in place (e.g., metal hangers and bolts) and everything’s ready to connect. Once installed, teams verify that strapping screw and nail patterns are correct and all penetrations for ductwork and piping are in the proper locations.

“Mass timber has advantages over concrete,” Govan said. “It’s easier with the logistics and there are fewer constraints than working with steel, like getting ‘hot work’ permits for all the welding. Plus, you eliminate the risk of fire from welding sparks.”

“It’s pretty much like Lincoln Logs,” he added. “It shows up, it’s numbered, it goes together easily and modifications are minor.”

According to Beyer, who’s been building at Swinerton since 2003, construction with mass timber shares similarities with steel as a structural component. Both materials are produced to specification and joined together onsite, and product deliveries need to be in sync with erection scheduling. After that, mass timber can go up faster and once CLT is set in place between floors of a multi-floor building, work on the lower floors can start right away. Not so with steel, since concrete must first be poured and set for decking that separates floors.

Even though it weighs less, mass timber matches steel for strength and load capacity. Additionally, it has a smaller “carbon footprint,” meaning the amount of carbon dioxide produced by harvesting wood, cutting and shaping it, and transporting it is less when compared to manufacturing and transporting comparable amounts of steel and concrete.

Since mass timber is lighter than steel and concrete, the building foundation typically uses less concrete, further reducing its carbon footprint.

Mass timber appeals to many clients because it serves as both structure and interior finish. While the interiors of steel and concrete-framed buildings are usually covered over with drywall and other finishes, mass timber offers natural wood-grained beauty across expansive interior spaces. It’s known to enhance the workplace by drawing occupants closer to nature, something called biophilic design.

“One point inside the new building will also serve as a visual learning tool for students studying construction management and architecture,” said Ginger Thompson, senior associate with Swinerton’s design-build partner Dreyfuss + Blackford Architecture.

“The CLT panel deck acts as the structural floor and exposed feature ceiling, and it’s cut through and exposed between the floors in the stairwell,” she said. “Here, people can get a close-up view of how the system works. As a team, we’re so excited to be able to bring a new and sustainable construction method to the Chico campus, especially for a space that holds the Planning and Building departments,” Thompson added.

Finally, Swinerton is delivering to Chico State the key benefits it sought – space filled with daylight, a low-carbon footprint, and an enhanced occupant connection to nature – in a cost-neutral mass timber structure.

The mass timber project at Chico State is one of three currently underway in Northern California for Swinerton’s Sacramento division.

At Cal Poly Humboldt, Swinerton has begun construction of a $86 million Engineering & Technology Building with design-build partner AC Martin. The three-story, 74,000-square-foot mass timber structure is planned to be completed in 2026. At the same time, Swinerton, in collaboration with SmithGroup, is beginning work on the $22-million mass timber Energy Research & Sustainability Center. The two-story, 20,000-square-foot structure is expected to be completed by Fall 2025.