The Millennium Tower, a leading symbol of San Francisco’s new high-rise and high-end living, is sinking — setting the stage for what could be one of the most contentious and costly real estate legal battles the city has ever seen.
Rated by Worth magazine as one of the top 10 residential buildings in the world, the Millennium at 301 Mission St. is home to such A-listers as Joe Montana and Hunter Pence. Until his recent death, it’s where venture capitalist Tom Perkins owned a penthouse. Condos sell for anywhere from $1.6 million to north of $10 million.
However, since its completion in 2008, the 58-story building has sunk 16 inches, according to an independent consultant hired to monitor the problem. It has also tilted 2 inches to the northwest.
“That’s significant … and of concern,” said Professor Greg Deierlein, director of the John A. Blume Earthquake Engineering Center at Stanford University, who has been called in to evaluate the designs of a couple of San Francisco’s newer downtown high-rises.
Deierlein noted that the 88-story Petronas Twin Towers in Malaysia — which were the world’s tallest buildings when they opened in 1998 — have sunk less than 3 inches. Their tilt, or “differential settlement,” is less than half an inch.
This isn’t just an issue for the Millennium’s owners and wealthy inhabitants: It could be a headache for taxpayers as well. There are potentially big public dollars at stake, with the owners alleging that the massive hole dug next door for the new Transbay Transit Center is to blame for the building’s issues.
The problem first came to light in 2010 when the Transbay Joint Powers Authority, the public agency constructing the transit center, hired the consulting firm Arup to gauge how the excavation could affect the tower.
According to the consultant’s initial report, by the time excavation began — two years after the $350 million Millennium was completed — the tower had already settled 10 inches. That was 4 inches more than its builders had predicted for the life of the high-rise.
Since then, “the building has continued to settle vertically, now 16 inches,” representatives of the Transbay Joint Powers Authority said in a statement in response to questions from The Chronicle.
At the same time, geotechnical reports show that since 2009, the settling has been uneven — resulting in the 2-inch tilt.
And while Stanford’s Deierlein doesn’t consider the sink or tilt a safety issue, he did say, “I would be concerned for my investment.” That’s because a shifting building can cause walls to crack, elevators to malfunction and all manner of other annoyances.