Demonstrating civic leadership through design

When San Mateo County leaders approached SOM to design a new county headquarters, they had ambitious sustainability goals. Climate leadership is needed now more than ever, and this county on the San Francisco Peninsula is particularly vulnerable to the perils of climate change, including wildfire, drought, and sea-level rise. County leaders were also cognizant of the symbolic weight and long-term impact that this building will have. Civic buildings are built to endure for generations, and when purposefully designed, these structures can convey a municipality’s values, identity, and aspirations. With its use of cross-laminated timber to reduce embodied carbon, and an efficient design that targets net zero energy in operations, County Office Building 3 (COB3) stands as a testament to San Mateo County’s environmental stewardship.

Reducing embodied carbon with mass timber

Every decision in construction detailing and structural design was motivated by the goal of reducing the building’s carbon footprint. Leveraging craftsmanship, engineering knowledge, and insight from the firm’s research on mass timber construction, SOM reduced the amount of timber required for the structure and pared down the number of steel components. While a typical mass timber structure has 65 to 75 percent less embodied carbon than a conventional steel structure, COB3’s structural timber design archives an 85 percent reduction.

Additional carbon reduction was possible through the elimination of materials–such as conventional hung acoustical ceilings, which were replaced by alternative acoustical solutions–and the specification of low-carbon materials. The prefabricated timber components made the construction process faster and more precise than conventional building processes, further reducing carbon impact.

Strategies for net-zero energy

Targeting LEED Platinum certification, COB3 is also designed to achieve net-zero energy. Solar arrays on site produce the energy needed for the building’s operations, while passive design strategies reduce energy use. The glass enclosures on the building’s north and south facades are recessed and shaded, while, on the east and west sides, a series of fins protect the windows. These measures minimize heat gain, reduce the need for artificial cooling, and optimize daylighting.

Enlivening downtown

From an urban design perspective, the new County Office Building is configured to link two distinct and previously disconnected neighborhoods of Redwood City: the civic campus to the east, and the downtown commercial core to the west. The new building completes the sense of a civic campus. The H-shaped building creates two new civic plazas, one facing the eastern campus and the other opening toward downtown. With amenities including a café, a gym, and meeting rooms, the active street frontage on both sides of the building contributes to a strong public realm. The glass-enclosed lobby which links the two plazas serves as a pre-function and event space for the County’s Board of Supervisors’ Chamber Auditorium.

A healthy and uplifting workplace

Together with the project’s environmental goals, the county sought to create a first-rate workplace that elevates the experience for its users. The workplace design breaks down large floor plates into intimate sections. Relatively narrow, the 65-foot-wide floorplates maximize natural light. At the center of each floor, collaboration spaces are customized to each department. Top floors feature terraces, kitchenettes, conference rooms, and collaboration spaces. Internal stairways link these spaces across floors creating an active and interconnected workplace.

All occupants benefit from a design approach centered on biophilia, creating a sense of connection to nature. Timber wraps the lobby interior, and wood slatting continues as a motif throughout the building, echoing the exposed wood structural frame. The abundance of natural wood creates a soothing, visibly low-carbon environment. Natural ventilation and views toward the surrounding landscape further contribute to well-being.