Caltrain, Prologis File Plans for Massive 20-Acre SoMa Railyard Redevelopment

Prologis and Caltrain have submitted a formal application to the San Francisco Planning Commission to redevelop the 20-acre Caltrain Railyards along Townsend Street, proposing what would become one of the most ambitious mixed-use projects in the city's post-pandemic pipeline: up to 8 million square feet of development built in phases over 15 to 20 years above an active rail yard between SoMa and Mission Bay.

The proposal envisions roughly 2,500 housing units alongside approximately 4 million square feet of commercial space that could include office, retail and potentially a hotel. Anchoring the project would be an 850-foot tower rising above a rebuilt Caltrain station, which, if constructed, would rank among the tallest buildings in San Francisco. The first phase alone would span about 2.5 million square feet, centered on parcels at Fourth and Townsend and Seventh and Townsend.

The project now enters formal environmental review with the city.

Prologis, the world's largest owner and developer of logistics real estate, owns the railyards property and would act as master developer for the transit-oriented district. The company is already pushing beyond its traditional warehouse portfolio in San Francisco: its Gateway project in the Bayview neighborhood mixes production, distribution, repair and retail in a dense multi-story format. The railyards plan goes further still, blending logistics-adjacent land with housing, commercial development and a rebuilt transit hub.

Genevieve Cadwalader, vice president for Prologis, framed the filing in terms of long-term commitment to San Francisco. "This application reflects Prologis' long-term conviction in San Francisco, and we are ready to move this transformational investment forward," Cadwalader said. "We are proud to work alongside Caltrain and the City of San Francisco to achieve an innovative public-private project that will create a dynamic mixed-use neighborhood, enhance mobility and thousands of jobs."

Mayor Daniel Lurie offered his support in a statement: "This project will continue that momentum up into SoMa, leading with public space and transit access. The team behind this project has a bold vision for the neighborhood, and I appreciate their dedication to our city's comeback."

Today the active rail yard functions as a physical barrier separating SoMa, Showplace Square and Mission Bay. Prologis and Caltrain are positioning the redevelopment as a way to stitch those three neighborhoods together through new housing, transit improvements and public space distributed across multiple buildings. The rebuilt Caltrain station at the base of the proposed tower would serve as the district's central spine.

The railyards have drawn redevelopment interest for the better part of two decades. SPUR presented an early think piece on the site's potential, and the late Mayor Ed Lee raised the idea during his tenure. Prologis and Caltrain began more seriously exploring a concrete plan in 2021. The formal application filed this week marks the first time the proposal has entered the city's official planning process, making it one of the first major mixed-use megaprojects to reach that threshold since the pandemic effectively halted large-scale development in San Francisco.

The phasing timeline, which some reporting characterizes as potentially stretching even longer than two decades, will likely come into sharper focus once environmental review is underway.