I must have walked past the building at the corner of Main Street and Harrison Street 50 times without ever really noticing it. Normally I’m at least aware of historical structures, but this one, with its mauve mullions set amid dirty, peeling shades of beige, was particularly featureless. Then I started to work on its adaptive reuse, and its potential was revealed.
The building was constructed in 1942, a time when manufacturing and utilitarian warehouses dominated SOMA, the neighborhood south of San Francisco’s Market Street. The 8-story structure, which takes up an entire block, was built as a military warehouse, with 10-foot ceilings and floor plates of 63,000 square feet. Like many SOMA warehouses of that time, the building’s ground floor let freight trains pass through for loading and unloading. It was first used for military storage through World War II; later, when the building was known as the Rincon Annex, its postal workers sorted all mail addressed to the war zones in Korea and Vietnam. Then, for years, it went mostly unused. Occasionally, the police department used it for target practice.
Eventually, Perkins+Will was selected by the Bay Area Headquarters Authority, a coalition of four regional governmental agencies, to help them realize the Bay Area Metro Center: a new, collaborative workplace that would bring four regional governmental agencies—the Metropolitan Transportation Commission, the Bay Area Air Quality Management District, the Association of Bay Area Governments, and the Bay Conservation and Development Commission—under one roof. Although their intersecting missions frequently complement each other, each agency’s headquarters had long been at separate sites scattered throughout the Bay Area. Through the sheer enormity of the existing structure, these agencies could unite, pool resources and benefit from the synergies of closeness. In addition to seven floors of workspace, the program included a public-facing room for commission hearings, multiple conference rooms, break-out spaces, two libraries, a bike storage area, and ground-floor retail.
Retaining the existing building presented a number of design challenges: How does a warm, welcoming environment grow from a dark, uninviting, even cavernous structure? How do we foster collaboration when workers are located across multiple enormous floors? What glamour can be wrung from a huge concrete box, while keeping to a firm budget?
For the crux of our design solution, we introduced light and connectivity by carving an eight-story central atrium out of the building’s floor plates and adding a floating stair, all lit by a massive skylight above. Recalling a geode, the building now faces inward to its most spectacular feature, the atrium.
The new sense of scale and light is breathtaking, especially in contrast to the building’s utilitarian bulk. Cutting a light shaft into such huge floor plates revealed opportunities for distinct spaces and interactions. On the public-facing ground floor, wood contrasts with the existing concrete columns and enlivens the atrium space at the ceiling, guardrails, slab edges, and certain walls. The multi-purpose rooms and the commission hearing room open onto the atrium using a framed angular portal language that continues throughout the building. Office workers meet at the upper platforms in the atrium, pass each other on the hanging stairs, gaze from the ground floor benches up to the sky, and see fellow workers on the other side of the atrium. In place of the entry for freight trains, we incorporated a double-story, canted opening on the building’s northwestern side at ground level. Nearby, two new retail spaces flank the main entrance and open onto the atrium, increasing foot traffic and providing dining options for employees and visitors.
The building’s seismic retrofit hinged on the central atrium. Because its creation required scooping out so much material, the building’s overall structural mass was reduced, allowing for shotcrete walls at the perimeter only. Avoiding the typical solid, central core meant unimpeded views in either direction, toward the central atrium and the exterior windows. Also, structurally reinforcing the exterior shell meant wider walls and deeper window sills that effectively created light shelves—extending daylight farther into the building than before.
Aware of budgetary constraints, we made limited interventions to the building exterior using a language of portals, celebrating important interior programmatic elements. These portals are angular frames that interact with the existing window grid at the entrance, commission hearing room, roof terrace (with its spectacular view to the Bay Bridge and beyond), and primary view corridors. Wood is also prominent at the exterior, notably at the main entrance and a tree well located in the façade between the 6th and 8th floors. We also articulated the existing façade by designing a playful pattern of two shades of blue.
Sustainability was a key goal, and the project is currently pursuing LEED Gold certification. The ETFE skylight brings daylight into the center of the structure, decreasing the occupants’ energy use. Much of the exposed wood—stair treads, countertops, and wall finishes—is made of century-old wooden pilings uncovered during the demolition of the original Transbay Terminal. But the project’s most remarkable feature was the reuse of the structure itself. While its adaptation will garner only a few LEED points, it averted the relocation of a 500,000 square foot concrete warehouse to a landfill.
If this building had originally been conceived as a workplace there’s no doubt the design would have been quite different. It would not have had virtually square floor plate nearly the size of a football field, with 10-foot ceilings. The space likely would have faced outward to engage with the public it serves and maximized its views to the Bay Bridge. There certainly wouldn’t have been a double-story, canted opening for trains to pass through, nor the opportunity to carve out a soaring atrium.
But because of these limitations—not in spite of them—our design process took us in a unique, even spectacular direction. The Bay Area Metro Center is a one-of-a-kind experience for both employees and the public, and yet maintains a link to the neighborhood’s historic character.
The challenges that present themselves when transforming a warehouse into a modern workplace are formidable, but with them come the potential for truly spectacular solutions.
As the Associate Architects, TEF did the space planning, programming, furniture selection, and fit-out of floors 5-8. As the Structural Engineers, Holmes Structures engineered the buildings’ seismic retrofit.