Structure Type: built works - dwellings - houses - apartment houses

Designers: DeSimone Consulting Engineers (firm); Handel Architects (firm); Webcor Builders, Incorporated (firm); Gary Handel

Dates: constructed 2005-2009

58 stories

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301 Mission Street
South of Market, San Francisco, CA 94105

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Overview

Real estate development company Millennium Partners underwrote the $350 million required to build this residential complex consisting of an 11-story residential tower connected by a two-floor glass atrium to a neighboring 58-story high-rise, both home to some of San Francisco's wealthiest citizens. Begun in 2005, the Millenium Tower was completed in 2009 complete with ground-floor retail space and 419 residential units. According to some news reports, excavations for the nearby Transbay Transit Center may have caused the tower to settle 10 inches by 2016, 4 more than it was supposed to do over its entire lifetime. By 2016, the rate of settling had been uneven, and caused a tilt of 2 inches. The Millenium Tower, the tallest residential building in the city, became well-known for its predicament, even warranting a segment on the CBS News program, 60 Minutes.

Building History

In 2016, condominiums in the building ranged from $1.6 million to $10 million in price. Owners of the $350 million Millenium Project indicated that the Transbay Joint Powers Authority--an exercise of powers authority formed by the City and County of San Francisco, the Alameda-Contra Costa Transit District, the Peninsula Corridor Joint Powers Board, and Caltrans (ex officio)--had a legal liability for the tower's movement, alleging that the Transbay Transit Center's extensive excavation nearby undermined the highrise's foundations. The Millenium Tower was sited just to the east of San Francisco's original, 19th-century shoreline, on marshy soil covered by loose landfill.

Spokespeople for the Transbay Joint Powers Authority stated that it bore no responsibility for the Millenium Tower's lean: "Records show the Transbay Joint Powers Authority pumped more than $58 million into an underground buttressing system to shore up the Millennium before beginning excavation in 2010. That’s one of the many reasons for the new transit center’s spiraling costs, which are now at $2.4 billion and counting." (See Phillip Matier and Andrew Ross, San Francisco Chronicle.com, "SF’s landmark tower for rich and famous is sinking and tilting," published 08/01/2016, accessed 09/05/2018.)

The Millenium Tower's structural system may have contributed to the building's sinking and lean. Rather than being framed in relatively light-weight steel and sheathed in metal curtain walls, the Millenium Tower was formed of a very dense and heavy reinforced concrete frame. As reported by Matier and Ross of the San Francisco Chronicle: "Unlike some downtown high-rises, the Millennium isn’t steel-framed. Instead, the developer chose a concrete design more common to residential buildings. It relies on huge columns, shear walls and beams, and it’s much heavier than steel. What’s more, the building is located on unstable mud-fill, just off the bay’s original shoreline.The Millennium’s engineers anchored the building over a thick concrete slab with piles driven roughly 80 feet into dense sand. 'To cut costs, Millennium did not drill piles to bedrock,' or 200 feet down, the transit center authority said in its statement. Had it done so, the agency said, 'the tower would not be tilting today.'" It is the concrete platform that has sunk, taking the rest of the building bullt on top of it, with it. (See Phillip Matier and Andrew Ross, San Francisco Chronicle.com, "SF’s landmark tower for rich and famous is sinking and tilting," published 08/01/2016, accessed 09/05/2018.)

Building Notes

In 2018, a Bank of the West branch occupied ground floor space on the northeast corner of Mission and Fremont Streets.

PCAD id: 22316