Millennium Tower Retrofit Wins SEAONC Structural Engineering Excellence Award
The Structural Engineers Association of Northern California (SEAONC) recently honored the Millennium Tower foundation upgrade project at 301 Mission Street in San Francisco with an Award of Excellence in the organization’s 2025 Structural Engineering Excellence Awards (SEE) program. The Simpson Gumpertz & Heger (SGH) project earned the top prize in the Retrofit/Alteration category during SEAONC’s annual awards gala and celebration on 6 May 2025, and will continue on to the state-wide SEE Awards program.
The Millennium Tower is a fifty-eight-story luxury condominium building developed between 2005 and 2009. Over the next ten years, the structure settled 17 in. and tilted 17 in. to the northwest, resulting in litigation. To address these issues, SGH designed a unique structural upgrade, which involved installing eighteen piles along the building’s north and west sides, extending to bedrock to arrest further settlement and provide for gradual recovery of tilting. The remedial work was completed in September 2023, with occupancy continuing throughout the two-year project. The permit requires monitoring building performance for ten years, and the first eighteen months of monitoring indicated that the project has been successful, with settlement along the north and west sides arrested and gradual tilt recovery occurring.
“The project demonstrated a minimalist approach and capacity design principles to solve a challenging problem in a safe and reliable manner,” said SGH Consulting Principal Ron Hamburger, who led the project and accepted the award at the ceremony. “Despite high-profile attention from the local and national media, the project team persevered and completed the project successfully.”
SGH partnered with the ownership group Millennium Tower Association and general contractor Shimmick Construction on the project.
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