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
| Aug 30, 2013
A new approach to post-occupancy evaluations
As a growing number of healthcare institutions become more customer-focused, post-occupancy evaluations (POE) are playing a bigger role in new construction and renovation projects. Advocate Health Care is among the healthcare organizations to institute a detailed post-occupancy assessment process for its projects.
| Aug 29, 2013
First look: K-State's Bill Snyder Family Stadium expansion
The West Side Stadium Expansion Project at Kansas State's Bill Snyder Family Stadium is the largest project in K-State Athletics history.
| Aug 27, 2013
Industrial Sector Report [2013 Giants 300 Report]
Building Design+Construction's rankings of the nation's largest industrial sector design and construction firms, as reported in the 2013 Giants 300 Report.
| Aug 26, 2013
What you missed last week: Architecture billings up again; record year for hotel renovations; nation's most expensive real estate markets
BD+C's roundup of the top construction market news for the week of August 18 includes the latest architecture billings index from AIA and a BOMA study on the nation's most and least expensive commercial real estate markets.
| Aug 26, 2013
Chicago Bears kick off season at renovated Halas Hall
An upgraded locker room, expanded weight room, and updated dining room with an outdoor patio greeted the Chicago Bears when they arrived at Halas Hall for practice this month. The improvements are part of a major expansion and renovation of the Bears’ headquarters in Lake Forest, Ill., completed by Mortenson Construction in less than seven months.
| Aug 22, 2013
Energy-efficient glazing technology [AIA Course]
This course discuses the latest technological advances in glazing, which make possible ever more efficient enclosures with ever greater glazed area.
| Aug 22, 2013
Warehouse remake: Conversion project turns derelict freight terminal into modern office space [slideshow]
The goal of the Freight development is to attract businesses to an abandoned industrial zone north of downtown Denver.
| Aug 21, 2013
AIA: Architecture billings on the rise in July
The Architecture Billings Index for July was 52.7, up from a mark of 51.6 in June. This score reflects an increase in demand for design services (any score above 50 indicates an increase in billings).
| Aug 20, 2013
40 Under 40 retrospective: ‘U40s’ take on continuing ed, snake’s blood
Every month we’ll be touching base with past 40 Under 40 honorees to see what’s been happening in their professional and personal lives since winning the award. This month: An accomplished author of test-prep books and an architect who headed to China when the American economy turned sour.
| Aug 20, 2013
Top Data Center Architecture Firms [2013 Giants 300 Report]
Corgan, Gensler, HDR head Building Design+Construction's 2013 ranking of the largest data center architecture and architecture/engineering firms in the U.S.