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City Hall. San Francisco, California

© Michael Morrissey

In 1906 the Great San Francisco Earthquake destroyed the old City Hall along with much of the rest of San Francisco. By 1915 San Francisco proudly opens the doors to its New City Hall. A 500,000 square foot gold and copper domed building. It is a magnificent example of Beaux Arts architecture, with a sweeping elegant grand staircase, giant rotunda and a myriad of architectural details throughout.

74 years later, the building already suffering from neglect, short sightedness and malaise is damaged by the Loma Prieta earthquake on Oct. 17, 1989. The dome, all 90,000-tons of it, twists like a bottle cap, nearly four inches from its original position and unlikely to survive another tremor. In 1995 rehabilitation begins. $300 million dollars and four years later the work is done. The results are nothing short of breathtaking.

Underground In order to prevent the newly refurbished building from succumbing to future earthquakes, which seems to be the trend for city halls in San Francisco, the building is base isolated. The building was actual removed from it's original foundation and now sits atop about 600 stainless steel and rubber isolators. These isolators will act to dissipate shock waves generated by an earthquake and will allow the building approximately two feet of lateral movement. Should such an earthquake hit, a two foot "moat" surrounds the building giving it ample room to sway. The installed base isolation system on the new city hall makes it the largest base isolated building in the world as well as the only base isolated national landmark.

First Floor The ground floor, home to the grand staircase and the light courts, received much needed attention. Framing the dome on two sides are two 7,000 square foot light courts. Originally designed as open spaces lit from above with full length sky lights, both were brutally mauled by short sighted bureaucrats in the 1950's. The skylights were covered with concrete while the formerly well lit open spaces were filled with desks, chairs and incandescent lighting to accommodate midlevel civil servants.

One of the first orders of business was to remove the abomination that was the skylight coverings and return the open light courts to their intended splendor. These magnificent light courts now house a café, history and art exhibits as well as open public spaces.

The Dome The fifth largest dome in the world which was damaged by the 1989 earthquake has been reinforced with nearly 1,200 tons of steel which were not present before. This will ensure that the dome will travel with the rest of the building in the event of a future earthquake. The dome also boasts nearly $400,000 worth of gold leaf, designed to last at least 80 years.

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