Business Insider ~ Melia Robinson
The multimillion-dollar condos sinking in San Francisco
Bad news keeps piling up at the “leaning tower” of San Francisco.
Millennium Tower is a luxury residential high-rise that has sunk 17 inches and tilted 14 inches since it was completed in 2008. Though an inspection by the city showed it’s safe to occupy, the building’s wealthy residents take no solace. Their multimillion-dollar condos have tumbled $320,000 in value on average.
Click through to see what we know about the fate of Millennium Tower.
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Millennium Tower rises 58 stories above San Francisco’s Financial District.
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The city’s fourth-tallest skyscraper contains more than 400 multimillion-dollar condo units. It soars 645 feet in the air, providing residents with panoramic views of the Bay Area.
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Completed in 2008, Millennium Tower includes top-notch amenities, including a pool, fitness center, wine cellar and tasting room, movie theater, and concierge service.
Source: Millennium Tower
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In the first five weeks of sales, Millennium Tower sold $100 million worth of condos, the San Francisco Chronicle reported. The units ranged in price from $1.6 million to $10 million.
Source: San Francisco Chronicle and San Francisco Chronicle
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Some pretty famous tenants have called Millennium Tower home, including former San Francisco 49ers quarterback Joe Montana and late venture capitalist Tom Perkins.
Source: Business Insider
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But residents weren’t happy after learning in June 2015 that the building is sinking. It had settled 16 inches into soil and tilted two inches at its base when they were notified.
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So far in 2017, Millennium Tower has sunk an additional inch and tilted another two and half inches toward the massive Salesforce Tower under construction across the street.
Source: NBC Bay Area
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The developers of Millennium Tower, Millennium Partners, argue that construction nearby is to blame for any sinking or tilting. A city transportation hub, the Transbay Transit Center, broke ground next door in 2010 about two years after the Millennium Tower was completed.
Source: Business Insider
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The new terminal, developed by a transportation agency called the Transbay Joint Powers Authority, includes a 60-foot hole for the train tunnel and an underground buttress.
Source: San Francisco Business Times
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A founding partner of Millennium Partners said at a press conference there’s “only one issue” — construction for the new terminal pumped too much water out of the ground.
“Dewatering” is the process of removing groundwater or surface water from a construction site to provide a safe work environment and prevent erosion of the soil.
When the water levels under the Millennium Tower dropped, the sand compressed and caused the building to settle, according to Chris Jeffries, a founding partner at Millennium Partners.
The issue came to light in 2010, five years before tenants were notified, when the Transbay Joint Powers Authority hired a consultant to find out how excavation could affect the tower.
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The Transbay Joint Powers Authority maintains it is not at fault for the building’s sinking.
The agency released a statement on its website in fall 2016 condemning the allegations against it as a “distraction from the exclusive cause” of the tower’s tilt: “inadequate foundation.”
The statement also points out that Millennium Tower’s vertical settlement began two years before the Transbay Joint Powers Authority began doing any underground work.
Related: San Francisco’s new $2.3 billion transit center could be the most expensive bus terminal in the world
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Some critics blame the city of San Francisco for allowing Millennium Partners to anchor the building 80 feet into packed sand rather than 200 feet down to bedrock.
Millennium Tower sits on an array of nearly 1,000 pillars shoved into the ground.
Its own weight combined with the resistance of the soil underneath should keep it in place under most conditions, a professor of architectural design told real-estate blog Curbed.
The design isn’t all that unusual. Some of the city’s best known buildings, including the Embarcadero Center and SF MOMA, were built on sand instead of bedrock.
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The biggest cause for concern is the looming possibility of an earthquake.
For years, scientists have warned that the Bay Area is overdue for a devastating earthquake.
Millennium Tower sits on land that is prone to liquefaction, the process by which loose sand and silt behaves like a liquid in the event of an earthquake. The seismic activity causes water pressure in the sediment to increase and grains of sand to lose contact with each other, the US Geological Survey (USGS) explains. The soil may give out under large and heavy structures.
Oftentimes, the solution for tall buildings built in liquefaction zones is drilling down to bedrock. Millennium Tower’s neighbors, the $1.1 billion Salesforce Tower and the luxury high-rise 181 Fremont, are both anchored to bedrock. They’re still under construction.
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There’s good news and bad news for the residents of Millennium Tower. In January, a study by the city’s Department of Building Inspection found that the skyscraper is safe to live in.
“There was no evidence of life-safety concerns observed during the inspection,” the report said.
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Satellite images that show Millennium Tower sinking from space suggest it will continue to sink at a rate of two inches per year. That’s double what engineers earlier estimated.
Source: Business Insider
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Gaps found in the walls of some units could also present risks in the event of a fire, according to a report commissioned by the homeowner’s association.
Late in 2016, the building’s homeowner association hired firm Allana, Buick and Bers to investigate a unit owned by Paula Pretlow. Pretlow and several other residents complained in the past of “unexplained odors permeating their luxury units,” NBC Bay Area reported.
The consultants discovered openings arounds pipes and ducts in the walls. Typically, gaps like these are sealed with fire-resistant caulking to make sure fires are contained where they start.
If a small fire was to break out in the unit below where Pretlow lives, the flames could more easily spread to her condo or cause smoke damage in the walls, according to NBC Bay Area.
The report only pertained to the unit owned by Pretlow, though others could be susceptible.
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Now a group of Millennium Tower residents are fighting to get their money back.
The homeowner association has filed at least one class-action lawsuit against Millennium Partners and the Transbay Terminal developers so that residents can recover their losses in property value. The multimillion-dollar condos have dropped $320,000 in value on average.
People attempting to sell their condos have slashed listing prices – or disappeared from the market entirely – since their skyscraper-home made international headlines last year.
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Football legend Joe Montana and his wife are seeking $2.7 million in reimbursement and $1 million for “consequential damanges” for buying the condo they now call “uninhabitable”.
Source: SF Curbed
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As Millennium Tower keeps on sinking, its fate remains unclear.