County Administration Center Renovation, San Diego, California

The San Diego County Administration Center never closed. Not for a weekend of real downtime, anyway. The 1938 civic landmark on Pacific Highway stayed open to the public through a $105 million renovation that replaced nearly every system in the building, and ENR named it the Best Project in Renovation/Restoration in its 2026 West Best Projects awards on Oct. 26, 2026.

SILLMAN was lead designer and Turner Construction Co. was the general contractor. The County of San Diego, which owns the building, started the major systems program in 2019 and ran it in phases.

Project Scope

The renovation covers the full 315,000-square-foot building. Crews replaced or upgraded mechanical, electrical, plumbing, fire alarm, sprinklers, security, communications, emergency power, accessibility and seismic systems. The county’s own list adds a remodeled Board Chamber with new audiovisual gear, restored historic windows, a new red tile roof, elevator refurbishment, a replacement emergency generator and exterior painting.

All of that went in around marble corridors, terrazzo floors, bronze doors, steel windows, mosaic domes and WPA-era murals. Work followed the Secretary of the Interior’s Standards for Rehabilitation. Original paint colors came from lab analysis rather than a color match by eye. Seismic strengthening used fiber-reinforced polymer so the team didn’t have to cut into historic fabric.

BWE handled civil and structural engineering and IMEG did MEP and lighting. Milford Wayne Donaldson served as historic architect, ID Studios did interiors, and RTD Construction Management was construction manager. The Balboa Art Conservation Center handled conservation.

Why It Matters

Occupied renovations are where schedules go to die, and this one was occupied by an entire county government. Departments moved in and out of swing space at least 24 times, each move squeezed into a weekend or one to three days, and the next phase couldn’t start until the last one freed up space. Most work ran at night, on weekends and over holidays.

Decades of undocumented alterations meant the drawings were close to useless. The team laser scanned the building inside and out and coordinated new systems against what was actually there. ENR reports the program closed without a single OSHA recordable or lost-time incident, despite lead and asbestos abatement, crane picks and confined-space work above working offices.

For agencies sitting on aging, landmarked headquarters, the lesson is blunt. You can keep the building and the public counter open at the same time. It just takes phasing discipline most owners underestimate.

Project Team & Details