Built in 1917, the five–story, Professional Building stands as one of the largest buildings in downtown Eureka. Located in an earthquake-vulnerable area with poor soil conditions, this unreinforced brick masonry building was in desperate need of a seismic rehabilitation. Using high-performance engineering techniques, the existing interior steel gravity frames were augmented with new slotted bolted friction dampers, thus adding lateral stiffness and energy dissipation capacity for a major seismic event. Utilizing standard structural sections and readily available materials for design of the custom friction dampers, allowed construction of the newly rehabilitated mixed-use facility seismically unsound to be completed on time and within the budget. Architectural features that were also addressed as part of the rehabilitation included the refurbishment of the rooftop cornice and main entrance columns.