Situated in the rapidly changing Transbay Area of San Francisco, close to Market Street and the financial district, this transit-oriented development is at the core of downtown San Francisco. The Foster + Partners and Heller Manus design knits the new scheme with the urban grain of the city, enhancing pedestrian circulation through the site.
It comprises 26,000 square-feet of new public spaces, along with two mixed-use towers: a 625-foot, 54-storey mixed-use residential and hotel tower, and a 910-foot, 61-storey residential and office tower along First Street providing 2.4 million square-feet of new hotel, office and residential spaces in this downtown neighbourhood. It further restores and revitalises two historic buildings on First Street.
A particular challenge for the design team, the irregularly shaped site, also offers opportunities for innovation. The design creates a highly efficient and flexible off-centre service core that allows for uninterrupted floorplates. This creates a truly accessible square at the ground floor of the First Street tower. The tower has been lifted up to provide a five-storey tall ‘urban plaza’, which is completely open-to-air and accessible throughout the day.
This will be the most significant publicly accessible private space in the city featuring a restaurant and viewing platform, events such as concerts and farmers’ markets, as well as works of art set in a lush landscape. The hotel, residences and offices have separate entrances at ground floor, but share a common basement, loading dock and parking garage.
The design of the First Street tower is a response to San Francisco’s planning code that calls for proportionally reduced floorplates for higher floors. The tower takes on a crystalline form to articulate the façades on the skyline, and the floor plates are designed to allow tenants a high degree of flexibility.
Their open layout is supported by offset cores and a diagonal perimeter structure, developed for seismic stability and resulting in a lightweight structure that is intrinsic to the building’s aesthetic. The building foundations are also designed for maximum stability. The tower is 30 percent lighter than a traditional building with a central core of similar size. It features innovative MEP and vertical transportation systems developed to attain a LEED Platinum rating.
Completing the new urban ensemble, is the mixed-use tower along Mission Street, which occupies a vacant site that was earlier used as a parking lot. It will be home to a new hotel operated by Waldorf Astoria, alongside stunning apartments located on the top floors. The stone-clad building features unique ‘glass vitrine’ windows, and is designed to achieve a LEED Gold rating. The project is expected to be completed by 2021. Source and images Courtesy of Foster + Partners.