Heller Manus Architects, San Francisco
181 Fremont is a mixed-use, transit-oriented high-rise development in Downtown San Francisco’s new Transbay District. It stands out in a sea of new glass towers because of its eye-catching exoskeleton, diagonal bracing and sawtooth curtain wall. The glass façade is faceted along the megaframe, so its triangles form subtly different planes, animating its appearance.
Key features include the exoskeletal design, including shock absorbers within the diagonal elements of the structure, its foundations going to bedrock more than 260 feet (79 meters) below ground, and full Occupant Evacuation Operation (OEO) elevators – a first in the US. The full OEO elevator system allows the building to be evacuated in case of earthquake or fire via elevators, which eliminated the need for a third fire stair.
Local city ordinance requires the building to be set back, but instead, the design team embraced the challenge presented by the tapered design: each floor is different. Larger floor plates on the lower third are ideal for office, while floor plates ideal for residential use are located higher.