San Francisco commissions approve 545 Sansom '3 Transamerica' additions, raise Maritime Plaza shadow limit

San Francisco’s Recreation and Park Commission and Planning Commission on Dec. 14 approved a package of actions allowing a six‑story vertical addition and rehabilitation at 545 Sansom Street, a project sponsor and city staff said will add a fractional amount of shadow to Maritime Plaza while expanding public open space and activating the block around the Transamerica Pyramid.

Planning and Recreation and Park staff described the project as a rehabilitation of the historic nine‑story building at 545 Sansom with the demolition of nearby one‑story commercial buildings and a six‑floor addition that would create roughly 127,602 gross square feet total and add up to 49,999 gross square feet of new general office use. The sponsor also proposed a roughly 1,200‑square‑foot privately owned public open space (POPOS) directly adjacent to the Transamerica Redwood Park and about 1,800 square feet of private open space, plus enlarged retail and amenity space on the ground floor.

City planner Chris Towns, presenting the Recreation and Park Department’s shadow analysis, said Maritime Plaza currently has a 67.88% existing shadow load and that the proposed project "would add a fractional 0.0345% shadow increase for a total of 67.91%." Towns said the new shadows would occur only on the plaza’s western half, during late‑afternoon periods in spring and summer, with the maximum net‑new shadow day shown in the analysis as April 12 and Aug. 30.

Project owner representative Michael Schveau framed the work as an effort to make the Transamerica block more welcoming. "The building belongs to the people of San Francisco," Schveau said, and described investments in the lobby, restaurants, retail and cultural programming to bring more activity to the site.

Foster + Partners’ Simone Martin said the design aims to respect and celebrate the historic facades while opening nonhistoric frontages to activate Mark Twain Alley and connect the block’s open spaces. The architect said the vertical addition was set back to preserve the historic face of the building and to reduce visual impacts while providing outdoor spaces on multiple floors.

Recreation and Park commissioners debated the tradeoffs between preserving sunlight under the city’s Prop K sunlight ordinance and supporting the project’s public‑realm benefits. Commissioner Moore proposed an idea that commissioners and staff later described aspirationally as a kind of "savings account" for shadow allocation — a policy tool to translate shadow tradeoffs across public open spaces — but no formal policy change was adopted at the hearing.

Rec & Park moved and unanimously approved a joint resolution to raise the absolute cumulative limit (ACL) for Maritime Plaza. The Rec & Park Commission then voted to recommend to Planning that the net new shadow would "not have a significant adverse impact" on the use of Maritime Plaza; that motion also carried by recorded vote. After Rec & Park adjourned, the Planning Commission considered the remaining entitlements.

Planning Commissioners asked about the office allocation and whether the site had been evaluated for residential conversion; the project sponsor said the preserved historic building’s deep floor plates and structural constraints make office and retail the viable uses. Commissioners also discussed e‑bike charging and storage; project counsel and staff said the sponsor will include dedicated e‑bike charging infrastructure in the bicycle room and that the city’s staff will consider broader code updates to bicycle parking and charging in 2024.

The Planning Commission voted unanimously, 7–0, to adopt the shadow findings under Planning Code §2.95, grant the downtown project authorization and approve the office development allocation for up to 49,999 gross square feet of general office use. No letters of support or opposition had been recorded by staff in the administrative record at the time of the hearing.

The approvals allow the sponsor to proceed to subsequent permit stages, subject to standard conditions and design refinement steps; staff and the sponsor said final building permits and construction approvals remain subject to separate reviews and to any required building‑code updates for electrical outlets in bicycle rooms or other safety requirements. The Recreation and Park Commission adjourned after its actions; Planning remained in session and then adjourned following its votes.