Western Union Residences

Location: Philadelphia, PA
Renovation Architect: Cecil Baker + Partners

The Residences is an adaptive reuse of the existing Western Union Telegraph Building originally constructed in 1922. The approximately 210,000 SF building includes 100 residential units with ground level retail and below grade parking for 100 cars. The existing 4-story structure was composed of a structural steel frame with flat arch floor framing and a masonry veneer. The project included a 7-story vertical expansion to the existing building along with a new adjacent 12-story section constructed on an adjacent parcel.

The structural challenges for the vertical and horizontal addition were immense. The existing building had some residual capacity to support additional gravity load, but the lateral framing system required dramatic upgrades to resist seismic and wind loads. A supplemental braced frame and moment frame systems were introduced to transfer lateral forces to the foundation system. An inverted braced frame system was also introduced to distribute uplift forces throughout the superstructure with a horizontal truss system. A number of building foundations required underpinning to increase their load carrying capacity.

The adjacent horizontal expansion was founded on concrete caissons. The close proximity of the underground transit system and related utility structures required a series of 5’ to 7’ deep cantilever grade beams to support the 12-story structure. A structural steel frame was utilized with light weight concrete in order to minimize the weight on the foundation system, and provide maximum flexibility for the intricate building step-backs and penthouse conditions. The architectural design developed by Cecil Baker + Partners included a glass and metal façade above the existing masonry veneer along with staggered outdoor terraces for the residences.