San Mateo’s Tower Plaza high-rise is headed for a serious remake, with owner Tourbineau Real Estate Partners now formally proposing to turn the 12-story office tower at 2121 South El Camino Real into 144 one-bedroom rental units. Twenty-two of those would be reserved as below-market-rate homes. Plans describe a modernized facade, a new lobby, fitness space and landscaped courtyards, while most of the five-building Tower Plaza campus and its existing parking structure would stay largely as they are.
According to the City of San Mateo, the formal application (PA-2026-0019) labels the project as an adaptive reuse that converts the existing office tower into rental housing and subdivides the larger parcel so the neighboring low-rise buildings and parking can keep operating. The city’s project page lists a March 4 formal application, links back to preliminary plans submitted in November 2025 and outlines the amenity package and facade upgrades that are now on the table.
Tourbineau picked up the Tower Plaza campus last year for about $22 million, according to a Newmark marketing release that handled the sale. The brokerage materials played up the property’s proximity to Hillsdale and Hayward Park Caltrain stations and flagged the campus’s low office occupancy at the time, a combination that investors say makes a housing conversion look far more attractive than chasing new office tenants.
From 156 Units To A Leaner 144 Unit Plan
This is not Tourbineau’s first swing at a conversion. A preliminary application filed in November floated roughly 156 apartments, with a mix of studios, one-bedrooms and two-bedrooms and about two dozen affordable units. That earlier concept was outlined by SF YIMBY. The new, formal filing tightens the program to an all one-bedroom lineup and trims the affordable set-aside slightly, signaling a pivot toward smaller, predominantly market-rate units that are often easier to pencil out.
Design, Amenities And What Stays Put
Recent reporting describes the tower as roughly 169 feet tall and about 109,500 square feet overall, with around 83,500 square feet expected to become residential space under the current plan. As summarized by The Real Deal, the proposal would keep the existing parking structure and most of the surrounding low-rise buildings, while adding resident amenities such as a lounge and fitness area and swapping out windows and exterior finishes to give the tired office tower a more residential look.
How The Approvals Could Play Out
To speed things along and lock in development rules, Tourbineau is leaning on two state housing laws, the Housing Crisis Act SB 330 and the Affordable Housing and High Road Jobs Act AB 2011. The text of those bills limits certain local rule changes after a project’s initial filing and creates streamlined review paths for qualifying housing projects. That legal backdrop arrives as San Mateo works under an aggressive 2023 to 2031 Housing Element that assigns the city a Regional Housing Needs Allocation of 7,015 units, a target planners say will influence how office conversions and new apartment buildings are judged.
A public meeting for the Tower Plaza proposal has not been set yet, and city staff say future materials and dates will show up on the project page as the review moves along. For nearby residents, the project is shaping up as an early test of how San Mateo handles office-to-residential conversions along the El Camino corridor while the city and the state keep the pressure on for more housing near transit.
