This skybridge completes the vision of creating a fully interconnected urban campus for Twitter within the two buildings of the historic San Francisco Furniture Mart. Spanning 100-feet above a pedestrian alley in San Francisco’s Mid-Market district, this passageway connects the historic Art Deco building with its neighboring annex, recently converted into new office space for the technology company.
At a functional level, the 35-foot-long crossing effectively creates nearly 100,000-square-feet of contiguous office space on a single floor. The bridge connects two distinct spaces—on one end a double-height main dining hall and all-hands space; on the other, two light-filled floors of specialty dining. By connecting these collective amenities, the new skybridge provides opportunities for employees to intermingle as they traverse between the two buildings, while also fostering a greater sense of community within the company.
The volume of the skybridge is strategically shaped in response to a series of site-driven constraints, resulting in a distinctively sculptural form. Since the ninth floors of both buildings differ in elevation by nearly five-feet, the skybridge slopes downward, forming a ramp, to mediate the difference in floor heights. Similarly, the roofline stretches upward to connect to a tenth-floor overlook, thereby establishing a visual connection between dining spaces in both buildings.
In plan, the bridge tapers as it crosses to the newer building to accommodate slight differences in the column grids between buildings. What began as a response to the physical variation between the two buildings was embraced as a formal strategy: the squeezing and stretching of the volume results in perspectival illusion, both within the bridge and when viewed from below.
On the exterior, standard curtainwall extrusions have been modified to accept layered sheets of frameless glass, resulting in ever-changing patterns of shadow and reflection. On the bridge’s underbelly, silver aluminum panels are shingled in correspondence with the curtainwall to create a textured ‘third-façade’ when viewed from below. Together, the shingled face of the bridge envelope adds a layer of delicacy to its sculptural volume.
The structure, designed to withstand 12-inches of lateral movement at both ends, is fully concealed. At the historic edifice, seismic bearings are hidden within a tapered blackened-steel portal that relates to the exposed concrete interior of the all-hands space. At the newer building, the bearings are concealed below a floor landing at the end of the ramp. By strategically hiding these complex structural elements, visual emphasis can remain on the skybridge’s delicate sculptural form.
The materials palette is intentionally minimal. Rift-sawn white oak flooring adds an element of warmth in contrast to the otherwise cool palette. Transparent ultra-clear glass allows activity within the skybridge to be observed from the retail plaza below, openly engaging the civic context. In the daytime, the tiled glass reflects the colors and changing hues of the sky; at dusk, the skybridge is softly illuminated, glowing as an urban lantern.
Bohlin Cywinski Jackson is an American architecture firm founded by Peter Bohlin and Richard Powell in 1965. Our work ranges greatly in scale and context—from significant civic, corporate, cultural, and university buildings to exceptional private residences, both large and small. From the beginning, our architecture has been distinguished by its extraordinary response to the varied natures of people and place. We believe in an architecture that reflects the particular qualities and spirit of place, honoring the rich possibilities of craft and material expression.