Footbridge with a feathered all-glass facade linking Twitter’s two headquarters buildings 100 feet above a San Francisco street.

Twitter’s new pedestrian bridge links two of their adjacent existing building headquarters. The architectural design intent called for a minimalist feathered all glass facade, without the expression of framing of pressure caps to the exterior.

This intent was further challenged by the large movements associated with the San Francisco seismic zone, budgetary constraints, and the bridge structure located 100 feet above street level.

Eckersley O’Callaghan responded to these challenges by engineering a modified unitized curtain wall system that allowed for pre-fabrication of units in the factory, thereby minimizing field labor and allowing a single pass installation without the need for sealing in the field.

The feathered glass detail without exterior framing was achieved by using a structural silicone glass attachment in conjunction with an adapter cassette that allowed the use of a standard pre-tested and certified aluminium curtain wall modified to achieve the desired aesthetic.

We were also responsible for the mullions, gasketing, coating selection and specification of the glazed panels.

Location
San Francisco, CA

Client
Twitter

Architect
Bohlin Cywinski Jackson