The award-winning Sonoma Academy Performing Arts Center (PAC) is a new two-level, 27,500-square-foot facility designed to integrate with the high school’s adjacent and award-winning Commons building and the rolling hillside. The PAC includes a 350-seat theater, an orchestra pit, an extensive lobby, theater support spaces, classrooms, and mezzanine balconies. It is linked to the school’s existing shop/maker space on the lower-floor level, and to the existing Commons building through a courtyard on the upper level.
Building the multi-level, multi-access PAC on a pad with a 14-foot incline was the initial major challenge that ZFA faced. The structural design involved a complex foundation and extensive concrete retaining walls to support the building and its interior changes in floor heights. Tying in elevated portions of the building into adjacent on-grade features required careful consideration and 3D modeling throughout the project. Complex geometry, primarily consisting of curved walls and sloped stadium seating, necessitated creative problem solving and detailing. Cold-formed steel shear walls provide a sleek solution to lateral support of the structure at various locations between the primary steel braced frames. The catwalk and tension grid structure were thoughtfully designed to maximize the efficiency of the users and the stage equipment while minimizing impact to the occupants below. Curved steel framing supports the soffit around the perimeter of the theater seating.
The roof and interior mezzanine were constructed with cross-laminated timber (CLT) supported by a steel frame. The underside of the CLT roof is exposed throughout the main level and lobby, which complements the adjacent building’s exposed CLT ceilings at the exterior. To maximize the glazing at the lobby, flush steel beams were inset into the CLT throughout, resulting in a continuous ceiling on the first level. The double cantilever CLT roof provides a striking aesthetic to the entrance of the building that demanded careful design and detailing to marry the structural performance with the architectural flair.