Atascadero City Hall Restoration & Seismic Rehabilitation
Atascadero, California
Client: City of Atascadero
Diani Building Corp. served as the general contractor for the restoration and seismic rehabilitation of the historic Atascadero City Hall, a landmark civic structure originally constructed in 1918 and severely damaged during the 2003 San Simeon earthquake.
Completed and reopened in 2013 after nearly a decade of planning and construction, the project transformed the previously red-tagged structure into a fully restored and seismically resilient civic facility, while preserving its historic architectural character.
The work required highly specialized construction methods to address both structural deficiencies and historic preservation requirements, including:
- Extensive seismic retrofitting of existing masonry walls using shotcrete and reinforced steel systems
- Structural upgrades to the building’s iconic rotunda and dome, including steel bracing and fiber-reinforced systems to improve seismic performance
- Upper dome structural re-framing, requiring precise engineering and construction sequencing to maintain the integrity of the historic architecture
- Selective demolition and reconstruction of upper structural elements to meet modern building standards
- Careful integration of new structural systems with historic materials, including detailed matching of finishes and architectural elements
Due to the absence of original construction documents, the project team relied on field verification, investigative demolition, and coordination with design professionals to accurately assess existing conditions and implement effective retrofit solutions.
The project was further complicated by multi-layered funding requirements, including coordination between FEMA and City funding sources, which required strict compliance, documentation, and phased execution throughout construction.
In addition to structural improvements, the project included extensive interior restoration, returning key architectural features such as the grand rotunda, ornamental plaster, and historic detailing to their original character while integrating modern building systems.
The result is a fully restored civic landmark, now capable of withstanding future seismic events while continuing to serve as the centerpiece of the Atascadero community.
This project highlights Diani Building Corp.’s expertise in complex seismic retrofits, historic restoration, and technically demanding public sector construction, successfully blending modern engineering with preservation of culturally significant architecture.
