Upon its completion in 1918, the building that is now the Atascadero (Calif.) City Hall was the very picture of stability. Intended as the centerpiece of Atascadero Colony—a planned utopian community—the Italian Renaissance structure featured a cruciform plan, with ornate central rotundas on the first and fourth floors.
Though the idealized colony never really jelled, the area did thrive, and the building passed through several commercial uses before the County of San Luis Obispo acquired it in 1950. When the city of Atascadero was incorporated 29 years later, the county handed the building over for city offices. The hall, with its grand pillared entrances and red-tiled dome, is featured on the city seal and listed on both the National and California Registers of Historic Places.
In December 2003, the 6.5 magnitude San Simeon earthquake ravaged Atascadero. As city workers dove for cover, the upper rotunda was twisted and wrenched away from its structural moorings. Interior walls and exterior masonry were extensively damaged, and the building was ultimately red-tagged. However, city officials were determined to restore, and improve, the beloved landmark.
Pfeiffer Partners Architects undertook a two-year assessment, including a laser-scan analysis as well as painstaking physical investigations and measurements. The Atascadero Historical Society, an enthusiastic collaborator, provided invaluable documentation of original conditions. Three packages of work were eventually developed: demolition, FEMA-funded damage repair and hazard mitigation, and city-funded rehabilitation.
PLATINUM AWARD
ATASCADERO CITY HALL
Atascadero, Calif.Building Team
Submitting firm: Bernards (construction manager)
Owner: City of Atascadero
Architect: Pfeiffer Partners Architects
Structural engineer: Nabih Youssef Associates
MEP engineer: Davidovich & Associates
General contractor: Diani Building Corp.General Information
Size: 58,900 sf
Construction cost: $21.7 million
Construction time: June 2010 to September 2013
Delivery method: CM agency/multi-prime
The 2008 economic crash posed financial difficulties, and anticipated state funding was eliminated in the subsequent recession. Meanwhile, water infiltration caused additional damage despite the owner’s best efforts to keep rain out. Under the management of Bernards, construction finally began in 2010, nearly seven years after the quake occurred.
Stabilizing the structure was obviously the most pressing need. The original building consisted of cast-in-place reinforced concrete floors and unreinforced masonry infill walls between a structural steel, concrete-encased post-and-beam skeleton. Above the fourth floor, the building was essentially an unreinforced masonry structure.
Crews strengthened the existing foundation by drilling 248 micro-piles 80 feet deep into bedrock, and pouring pile caps below the foundation. A new structural concrete slab-on-grade was installed at the basement level. Interior perimeter walls up to the fourth floor were stripped to reveal the structure, which was reinforced with more than a million tons of shotcrete and 80,000 pounds of rebar—in essence, creating a building within a building.
To fix the upper floors and dome, crews removed most of the exterior cladding, then rebuilt with additional steel and fiber-reinforced polymer instead of shotcrete, which would have been too heavy. Existing steel was horizontally and vertically braced, and roof dome framing members were retrofitted.
When structural improvements were complete, crews used as much of the original masonry as possible to rebuild the walls and roof. In the heavily damaged upper section, about 15% of the roof tiles and 80% of the bricks had to be replaced with color-matched materials. When possible, original tiles, fascia balustrades, and decorative plaster were repaired, cleaned, and returned to their original spots.
The lower rotunda benefited from a new paint scheme inspired by the greens and browns of the California landscape; the painter, a local artisan, donated half of his change-order hours back to the city. Second-floor window overlooks, once blocked, were uncovered and restored, providing views into the space from surrounding office zones. Light boxes behind frosted lunettes give the illusion of natural daylight. In reality, this dome is internal and is topped by a second rotunda housing the City Council chambers.
IMPROVING INTERIOR DESIGN
Interior reconfiguration was also crucial to improving functionality. Over the years, alterations had resulted in a confusing layout and awkwardly shaped spaces, as well as problematic ventilation. Crews removed most of the interior partitions and built new walls to establish a more sensible floor plan. Efficient HVAC and communications infrastructure was installed.
The lower rotunda was programmed as lobby space and a permit center. Three floors of offices surround this focal point. City Council chambers were constructed in the domed upper rotunda, which once held a library. A small historical museum received a place of honor, reinforcing the building’s link with the town.
More than 90% of construction dollars went to firms on the Central Coast, including $5.5 million to local glass, concrete, and masonry contractors. The final construction cost was $3.3 million less than the original $25 million estimate. Bernards credits the multi-prime contract process, encompassing 17 separately bid categories, for the savings. City Hall opened on schedule in August 2013, just in time for Atascadero’s centennial—an embodiment of civic resilience, determination, and pride.
Elegant detailing, a hallmark of the Italian Renaissance style, was re-established in the post-earthquake reconstruction.
Related Stories
Sports and Recreational Facilities | Jul 23, 2015
Japan announces new plan for Olympic Stadium
The country moves on from Zaha Hadid Architects, creators of the original stadium design scrapped last week.
Green | Jul 23, 2015
NASA: U.S. headed for worst droughts in a millennium
Data from NASA shows carbon emissions could be the driving force behind devastating water shortages and record droughts in the western U.S.
Airports | Jul 22, 2015
MUST SEE: JFK airport taps Gensler to design terminal for animals
Pets can enjoy luxurious spa and grooming services before being transported directly to their flight from the terminal.
Office Buildings | Jul 21, 2015
Finally! There's a workplace trend that’s worth embracing
There’s a realization by corporate real estate executives that in order to create a successful workplace, there must be alignment between their people, their place, and the tools they have to do their jobs.
University Buildings | Jul 21, 2015
Maker spaces: Designing places to test, break, and rebuild
Gensler's Kenneth Fisher and Keller Roughton highlight recent maker space projects at MIT and the University of Nebraska that provide just the right mix of equipment, tools, spaces, and disciplines to spark innovation.
Architects | Jul 21, 2015
Architecture Billings Index at highest mark since 2007
This is the first month in 2015 that all regions are reporting positive business conditions, said AIA Chief Economist Kermit Baker.
BIM and Information Technology | Jul 20, 2015
New stylus brings digital sketching to the next level
Without buttons, users can change the weight of the stylus’ stroke.
Architects | Jul 20, 2015
New York design competition looks to shed the sidewalk shed
New York, which has nearly 200 total miles of sidewalk sheds, is seeking a concept that is practical but that also looks good.
Cultural Facilities | Jul 19, 2015
SET Architects wins design competition for Holocaust Memorial
The design for the memorial in Bologna, Italy, is dominated by two large metal monolithic structures that represent the oppressive wooden bunks in concentration camps in Germany during World War II.
Sports and Recreational Facilities | Jul 17, 2015
Japan scraps Zaha Hadid's Tokyo Olympic Stadium project
The rising price tag was one of the downfalls of the 70-meter-tall, 290,000-sm stadium. In 2014, the cost of the project was 163 billion yen, but that rose to 252 billion yen this year.