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
| Mar 3, 2011
HDR acquires healthcare design-build firm Cooper Medical
HDR, a global architecture, engineering and consulting firm, acquired Cooper Medical, a firm providing integrated design and construction services for healthcare facilities throughout the U.S. The new alliance, HDR Cooper Medical, will provide a full service design and construction delivery model to healthcare clients.
| Mar 2, 2011
Design professionals grow leery of green promises
Legal claims over sustainability promises vs. performance of certified green buildings are beginning to mount—and so are warnings to A/E/P and environmental consulting firms, according to a ZweigWhite report.
| Mar 2, 2011
Cities of the sky
According to The Wall Street Journal, the Silk Road of the future—from Dubai to Chongqing to Honduras—is taking shape in urban developments based on airport hubs. Welcome to the world of the 'aerotropolis.'
| Mar 2, 2011
How skyscrapers can save the city
Besides making cities more affordable and architecturally interesting, tall buildings are greener than sprawl, and they foster social capital and creativity. Yet some urban planners and preservationists seem to have a misplaced fear of heights that yields damaging restrictions on how tall a building can be. From New York to Paris to Mumbai, there’s a powerful case for building up, not out.
| Mar 1, 2011
Smart cities: getting greener and making money doing it
The Global Green Cities of the 21st Century conference in San Francisco is filled with mayors, architects, academics, consultants, and financial types all struggling to understand the process of building smarter, greener cities on a scale that's practically unimaginable—and make money doing it.
| Mar 1, 2011
How to make rentals more attractive as the American dream evolves, adapts
Roger K. Lewis, architect and professor emeritus of architecture at the University of Maryland, writes in the Washington Post about the rising market demand for rental housing and how Building Teams can make these properties a desirable choice for consumer, not just an economically prudent and necessary one.
| Mar 1, 2011
New survey shows shifts in hospital construction projects
America’s hospitals and health systems are focusing more on renovation or expansion than new construction, according to a new survey conducted by Health Facilities Management magazine and the American Society for Healthcare Engineering (ASHE). In fact, renovation or expansion accounted for 73% of construction projects at hospitals responding to the survey.
| Mar 1, 2011
AIA selects 6 communities for long-term sustainability program
The American Institute of Architects today announced it has selected 6 communities throughout the country to receive technical assistance under the Sustainable Design Assessment Team (SDAT) program in 2011. The communities selected are Shelburne, Vt., Apple Valley, Mn., Pikes Peak Region, Co., Southwest DeKalb County, Ga., Bastrop, Tx., and Santa Rosa, Ca. The SDAT program represents a significant institutional investment by the AIA in public service work to assist communities in developing policy frameworks and long term sustainability plans.
| Feb 24, 2011
Perkins+Will designs 100 LEED Certified buildings
Perkins+Will announced the Leadership in Energy and Environmental Design (LEED) certification of its 100th sustainable building, marking a key milestone for the firm and for the sustainable design industry. The Vancouver-based Dockside Green Phase Two Balance project marks the firm’s 100th LEED certified building and is tied for the highest scoring LEED building worldwide with its sister project, Dockside Green Phase One.
| Feb 24, 2011
New reports chart path to net-zero-energy commercial buildings
Two new reports from the Zero Energy Commercial Buildings Consortium (CBC) on achieving net-zero-energy use in commercial buildings say that high levels of energy efficiency are the first, largest, and most important step on the way to net-zero.