Los Angeles City Hall

Los Angeles City Hall, completed in 1928, is the center of the government of the city of Los Angeles, California, and houses the mayor's office and the meeting chambers and offices of the Los Angeles City Council. It is located in the Civic Center district of downtown Los Angeles in the city block bounded by Main, Temple, First, and Spring streets, which was the heart of the city's central business district during the 1880s and 1890s.
The building was designed by John Parkinson, John C. Austin, and Albert C. Martin, Sr., and was completed in 1928. Dedication ceremonies were held on April 26, 1928. It has 32 floors and, at 454 feet (138 m) high, is the tallest base-isolated structure in the world, having undergone a seismic retrofit from 1998 to 2001, so that the building will sustain minimal damage and remain functional after a magnitude 8.2 earthquake. The concrete in its tower was made with sand from each of California's 58 counties and water from its 21 historical missions. City Hall's distinctive tower was modelled after the Mausoleum at Halicarnassus, one of the seven wonders of the ancient world, and shows the influence of the Los Angeles Public Library, completed shortly before the structure was begun. An image of City Hall has been on Los Angeles Police Department badges since 1940.
A City Council ordinance passed in 1905 did not permit any new construction to be taller than 13 stories or 150 ft (46 m) in order to keep the city's architecture harmonious. City Hall's 454 ft (138 m) height was deemed exempt as a public building and assured that no building would surpass one third its height for over three decades until the ordinance was repealed by voter referendum in 1957. Therefore, from its completion in 1928 until finally surpassed by the topping off of Union Bank Plaza in 1966, City Hall was the tallest building in Los Angeles and shared the skyline with only a few structures such as the Continental Building, the only property built taller than 150 feet (46 m) prior to the ordinance, and the Richfield Tower and Eastern Columbia Building, which exceeded the ordinance through a loophole allowing for decorative towers.
City Hall has an observation deck, free to the public and open Monday through Friday during business hours. The peak of the pyramid at the top of the building is an airplane beacon named in honor of Colonel Charles A. Lindbergh, the Lindbergh Beacon. Circa 1939, there was an art gallery, in Room 351 on the third floor, that exhibited paintings by California artists.
The building was designated a Los Angeles Historic-Cultural Monument in 1976, and was listed on the National Register of Historic Places in 2025.
In 1998 the building was closed during a total $135 million refurbishment which also included upgrading it so it could withstand a magnitude 8.2 earthquake, including permitting it to sway in a quake.
Prior to the completion of the current structure, the L.A. City Council utilized various other buildings:
The Mayor of Los Angeles has an office in room 300. Every Tuesday, Wednesday, and Friday at 10:00 am, the Los Angeles City Council meets in its chamber.
An observation level is open to the public on the 27th floor. This floor's interior comprises a single large and highly vaulted room distinguished by the iconic tall square columns that are far more familiar as one of the building's most distinguishing exterior features. As this ample interior space is named, the Mayor Tom Bradley Room is used for ceremonies and other special occasions.
City Hall and the adjacent federal, state, and county buildings are served by the Civic Center station on the Metro B and D subway lines and the Historic Broadway station on the Metro A and E light rail lines. The J Line stops in front of the building.
The Los Angeles Dodgers wore a commemorative uniform patch during the 2018 season celebrating 60 years in the city depicting a logo of Los Angeles City Hall.
The building has been featured in the following popular movies and television shows. It also appears incidentally as an icon of officialdom in many movies from the Golden Age of Hollywood.
The seismic retrofit of Los Angeles City Hall is precedent‐setting for being the tallest building ever to be base isolated. The hybrid damping system that was developed reduces the level of inter‐story drift, story shear, and acceleration experienced by the tower structure to maintain continuous use and preserve its historic features during future seismic events.
Los Angeles City Hall was designed to resemble an ancient wonder of the world and was dedicated in 1928. This historic landmark is a 36‐story, 460 foot tall, steel‐frame building with riveted connections. The gravity system consists of a concrete encased steel frame and reinforced concrete slab/pan‐joist floor system. The typical beamto‐column connection is a riveted “wind connection” with top and bottom seat angles. City Hall was built prior to the enactment of explicit seismic design requirements, and is the first building in Los Angeles to exceed the 150 foot height limitation for all privately constructed buildings.
City Hall, being culturally/historically significant and an essential government facility, needed restoration and strengthening work to be performed in order to remain functional after a magnitude 8.2 quake on the San Andreas fault. Project requirements also called for compliance with all current life safety requirements, and the protection of the building’s exterior façade and historic interior fabric, which were frequently damaged during regional earthquakes over the last 70 years.
Seismic performance criteria could not be easily developed using code‐based approaches, since code techniques are not capable of predicting damage levels or the specific performance of a building. Additionally, the structural system and type of construction used for City Hall is prohibited by current codes. The City of Los Angeles required considerable convincing to select the base isolation scheme that proved to be the most efficient and effective design strategy, based on results of non‐linear analysis. LA City Hall would be the tallest building ever to be base isolated by more than doubling the story‐height previously reached with the same system. Concern focused on the building’s tendency to overturn or flip during an earthquake, and on making sure the building’s seismic resistance level was never reduced or compromised during construction with interim bracing. Equally challenging and critical to the comprehensive seismic renovation of City Hall was the assurance that years of valued cultural heritage would not be lost.
The seismic system developed for City Hall was a hybrid system combining seismic isolation bearings, shear walls, and viscous dampers at the top of the structure and the plane of isolation at the base. This system provides a level of life safety and damage control that exceeds the level provided by conventional strengthening schemes.
Nabih Youssef Associates Structural Engineers (NYA) had to establish the seismic performance goals in order to develop the criteria for the evaluation of the existing structure and the design of potential strengthening schemes. These performance goals were quantified in engineering criteria as analytical limit states, which were determined using the latest research data available regarding the seismic performance of existing buildings combined with guidelines developed for life safety protection and damage mitigation. Various in‐situ tests were also performed to determine the properties and strength of the materials used to construct the existing building. The results of the tests were used to develop non‐lnear models of structural components of the building that were incorporated into models of the global structure. These global models were verified by ambient and full‐scale forced vibration tests performed on the building to account for all non‐structural systems contributing to stiffness. The models were used to perform non‐linear dynamic analyses of the existing and base isolated building.
The base isolation system consists of 416 high damping rubber bearings, 90 flat sliding bearings, and 52 viscous dampers installed between the basement and foundation levels of the building. The viscous dampers were added to limit the maximum displacement at the plane of isolation and to dissipate seismic energy from near fault seismic events. The isolation system is designed for a maximum displacement of 21 inches. Thick concrete outrigger walls were also designed for the basement and subbasement levels to distribute axial loads over a number of bearings when subjected to overturning moment. At columns where net vertical displacements were anticipated, specially designed loose bolt connections were made to prevent damage to the isolation bearing. During construction, two‐feet thick, two‐story high concrete shear walls were added under the tower portion of the building to carry the existing column loads during the installation of the base isolation bearings, saving considerable installation time and cost.
The existing reinforced concrete walls of the superstructure were strengthened and 12 viscous dampers were installed at the 24th floor – results of the analyses indicated that the upper portion of the tower experienced amplified response (whiplash effect) due to the significant change in lateral stiffness in the transition to the 25th floor – to reduce the acceleration response at the top of the building. LA City Hall became one of the most comprehensive seismic upgrades in the country. The hybrid damping system that was developed is especially effective in controlling the response of LA City Hall to earthquake ground motions. After all was done, including minor interior remodeling, code‐related improvements, and earthquake repairs, City Hall now stands visibly possessive of its old historic look, albeit with an up‐to‐date performance level.
2004 SEAOC “Excellence in Structural Engineering Award for Best Historic Preservation”.
2002 Los Angeles Conservancy “Preservation Award”.
2002 City of Los Angeles Cultural Heritage Commission “Heritage Award” “Hybrid System for Response Modification through Isolation & Supplemental Damping at Multiple Levels”.
City Hall South at 111 E. First Street, on the north side of First Street between Los Angeles and Main streets, built in 1952-4, architects Lunden, Hayward & O'Connor, International Style, originally opened as the City Health Building, housing health offices, clinics, and labs, and a central utility plant that heated City Hall proper and Parker Center (then police headquarters).
James K. Hahn City Hall East, 200 N. Main St., is located in the South Plaza of the Los Angeles Mall, a sunken, multi-level series of open spaces and retail space on the east side of Main Street straddling Temple Street. It is an 18-story, Brutalist, 1972 building by Stanton & Stockwell, featuring a mural by Millard Sheets, The Family of Man.