Apple Union Square

Structural Designer

Simpson Gumpertz & Heger Inc. and Foster + Partners

Client Name

Apple, Inc.


San Francisco, USA

ENGINEER OF RECORD: Simpson Gumpertz & Heger Inc.


PRINCIPAL CONTRACTOR: Ledcor Construction Inc.       

ARCHITECT: Foster + Partners        

MEP ENGINEER: Foster + Partners

GLASS DESIGNER (PERMIT): Eckersley O'Callaghan      


STEEL FABRICATOR: Orange County Erectors     

CONCRETE CONTRACTOR: Pacific Construction Company


Located on San Francisco’s Union Square, the new Apple store involved the addition of a new superstructure over a functioning basement ballroom and corridors. The project consists of three volumes: the store, the bar building, and the plaza. The store connects to Union Square on one side, to the plaza on the other and contains an 11m cantilevering mezzanine floor within the 13.5m high main space. The bar building beside the store transfers over the entrance ramp and loading dock of the neighbouring hotel. This project illustrates how the structural, environmental, and architectural visions have come together to form a holistic design.

Judge's comment:

The project includes three volumes: the Apple store, the bar building, and the plaza. The bar building and the plaza have been strengthened and modified and the store has replaced the old “Levi’s building” – constructed over a subterranean ballroom that remained in use during the construction.

The store, measuring 32m by 20.5m in plan, contains within the 13.5m high main steel-framed space, an 11m cantilevering mezzanine floor formed from tapered, built-up steel beams, where material reduces with demand and allows the realisation of the sharp floor profile. The south side has a large transparent façade with a pair of 12.8m tall sliding glass doors; the north side has a similar façade with 8m tall doors. The building is designed such that it would sustain little damage during earthquakes, allowing the store to be restorable to service following a major seismic event.

The judges were particularly impressed at the way in which the structure had been integrated within the architectural constraints of the building. For example, a perimeter concrete girder 2.4m deep and over 30m in length simultaneously supports the north façade and the sliding doors and counterbalances the cantilevering floor via built-up steel backspan beams that are anchored to it. There are also tuned mass dampers concealed in the cantilevering floor structure to reduce its vibration response.

The building transforms a previously unremarkable corner into a landmark destination with a new public plaza.

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