Two station boxes, one tunnel
The Portal puts two station boxes under downtown San Francisco and connects them with a tunnel. The authority describes the work as principally below grade, by cut-and-cover and mined tunnelling, beneath Townsend and Second Streets. The planned construction length is approximately 2.2 miles.
The western box is a new underground station at Fourth and Townsend Streets. Entrances along Townsend Street lead to a concourse one level below ground and a platform two levels down, with two tracks, a centre platform and two side platforms. The eastern box already sits in the basement of the Salesforce Transit Center and waits for fit-out. It carries six tracks and three centre platforms. The funding plan records $729 million of 2010 investment in that box.
Townsend Street between Third and Sixth
Contract 10-UR covers temporary and permanent advance utility relocations on Townsend Street between Third and Sixth streets, to facilitate the cut-and-cover portions of the tunnel. Design stands at 60 percent complete and moves to 90 percent once the engineering consultant is onboard.
A property owner on that stretch reads the scope as a description of the street outside the door.
Seven buildings in the demolition package
Contract 30-BD covers demolition of seven buildings to make room for the cut-and-cover portions of the tunnel and for a ventilation and emergency egress structure. Design on that package is 60 percent complete.
The record names the count. It does not name the addresses. No page on the authority sites lists the seven buildings, their block and lot numbers, or their owners.
The railyard edge at Fourth and King
Contract 20-YA covers relocation or removal of structures, utilities and storage tracks along the northern and western portions of the railyards. Contract 50-TS carries trackwork through the tunnel and stations and the at-grade work in the railyards. Design is 60 percent complete on 20-YA and 30 percent on 50-TS.
Hold point three is completion of Fourth and King Yard Preparation Package A, site clearing. Hold point four is completion of utility relocation.
What the fit-out package touches downtown
Contract 60-SF fits out the below-grade structural box at the Transit Center with facilities for rail operations and customer service. The concourse one level down takes ticketing, passenger waiting and support space for Caltrain and the California High Speed Rail Authority as primary tenants, alongside leasable retail. Design sits at 30 percent.
That retail line is the only commercial square footage the published packages add, and it sits on a level that carries no tenants today.
The assets that keep a walk to the platform
Straight-line distances computed from OpenStreetMap coordinates put five corridor hotels within about 640 metres of the Fourth and King platform. Hyatt Place at 701 Third Street is 335 metres, the Utah Inn at 504 Fourth Street 415 metres, Luma at 100 Channel Street 455 metres, Hotel VIA at 138 King Street 460 metres and Hotel Madrid at 22 South Park 636 metres.
Each of those five sells a walk to the train today. Once the platform moves into the Transit Center, the same five buildings sit 865 to 1,741 metres from the train.
The assets that gain a shorter transfer
Four hotels at the downtown end sit between 405 and 582 metres from the Transit Center. The Clancy at 299 Second Street is 405 metres, the Palace Hotel at 2 New Montgomery Street 507 metres, W San Francisco at 181 Third Street 576 metres and The St. Regis at 125 Third Street 582 metres.
Each of those four needs a vehicle or a Muni ride today. After fit-out, the Caltrain platform sits in the basement of the building 400 to 600 metres away.
The Clancy carries the additional exposure. Its address on Second Street places it above the mined tunnel alignment the authority describes.
The acquisition calendar at tranche level
Property interests come in four tranches across four instruments: property acquisition, permanent subsurface easements, temporary construction easements, and interests allowing the authority to install rock dowels in the subsurface of additional buildings.
The last two matter to an owner who is never bought out. A building that stays standing can still carry a temporary construction easement or a rock dowel encumbrance, and the published record does not map either to a parcel.
Tranche 1 holds five parcels. The September 2026 report records the boundary survey complete with a Record of Survey in first-round edits at San Francisco Public Works, four appraisals complete, two offers tendered after federal concurrence, and one appraisal package awaiting the FTA's review as to value. The remaining Tranche 1 stages run to the second quarter of 2027.
What an owner should watch next
Award of the Civil and Tunnel progressive design-build contract is hold point one. Property and right-of-way acquisition complete, with possession, is hold point two. Cut-and-cover excavation complete is hold point eight.
The September 2026 report records the 40-CT request for proposals issued in December 2025, about 155 requests for clarification, ten addenda published and proposals due 9 October 2026. The highest-scoring proposer is notified on 6 November 2026 and the contract award is forecast for 11 February 2027. That package stands at 30 percent design validation.
What the file does not carry
No source publishes the seven demolition addresses, a parcel-level acquisition list, a construction start date, or a service month inside the 2036 target. The budget stands at $8.255 billion. The 2025 estimate, approved through the federal environmental re-evaluation in August 2026, is approximately $7.572 billion, and the $683 million difference sits in unallocated contingency. The funding plan records a $587 million gap to be planned.
A property read built on this record describes exposure and position. It cannot date either.