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 20, 2014
WELL Building: The next step in green sports construction
The WELL Building Standard, a new protocol that focuses on human wellness within the built environment, is a particularly good fit for sports facilities, write Skanska's Tom Tingle and Beth Heider.
| Aug 20, 2014
Seattle's King Street Station thoughtfully restored [2014 Reconstruction Awards]
After years of neglect and botched renovations, King Street Station sparkles once again.
| Aug 20, 2014
Tour an office with no assigned workstations [slideshow]
The New York office of the Gerson Lehrman Group recently redesigned its office without personal desks or cubicles. The company gave each of its 250 employees a locker, a laptop, and told to work anywhere they wanted, according to Business Insider.
| Aug 20, 2014
Architecture Billings Index reaches highest mark since 2007
The American Institute of Architects reported the July ABI score was 55.8, up noticeably from a mark of 53.5 in June.
| Aug 19, 2014
Goettsch Partners unveils design for mega mixed-use development in Shenzhen [slideshow]
The overall design concept is of a complex of textured buildings that would differentiate from the surrounding blue-glass buildings of Shenzhen.
| Aug 19, 2014
HOK to acquire 360 Architecture
Expected to be finalized by the end of October, the acquisition of 360 Architecture will provide immediate benefits to both firms’ clients worldwide as HOK re-enters the sports and entertainment market.
| Aug 19, 2014
A designer's epiphany: 'Let's stop talking and make something'
Making things is important because it reveals gaps in thought, sheds light on the fundamental assumptions that can kill ideas, and forces us to push toward solutions that actually work, writes HDR's David Grandy.
| Aug 19, 2014
Construction boom lures new class of lenders in Nashville, says JLL
In the coming months, a gleaming S-shaped tower will join Nashville's burgeoning skyline. The new tower is just one example of a project financed not with conventional construction loans but with a unique blend of equity and debt.
| Aug 18, 2014
Perkins+Will expands planning practice with strategic focus on underserved U.S. communities
The broadened focus is resulting in comprehensive, long-term plans that will guide new growth in places like Buffalo, N.Y., Kingston, R.I., and Brooklyn, N.Y.
| Aug 18, 2014
SPARK’s newly unveiled mixed-use development references China's flowing hillscape
Architecture firm SPARK recently finished a design for a new development in Shenzhen. The 770,700 square-foot mixed-use structure's design mimics the hilly landscape of the site's locale.