Architect: Pelli Clarke Pelli Architects - www.pcparch.com

Design participation: Gregorio Vasquez

Transbay Transit Center and Tower aspire to become two of San Francisco's great buildings, expressing through architecture, engineering, and urban design the spirit of the neighborhood, city, and region.

The multi-modal, state-of-the art Transit Center is designed to be graceful, luminous, welcoming and safe. An exterior glass wall with undulating forms like petals of a flower will create a civilized presence on the street. These undulations also respond to the building's robust concrete-and-steel structural system, which is engineered for performance in the event of severe earthquakes.

A public plaza on Mission Street marks the primary entrance to the Transit Center. The main public space — the Grand Hall — will be suffused with natural light. The central element, a 120-foot-tall light column, is a structural component that reaches from the park to the Lower Concourse. Topped with a 4,000-square-foot domed skylight, the light column not only supports the building, but draws daylight deep into the interior and frames views of the park above.

The park is the heart of the Transit Center. Offering activity and as well as quiet relaxation, the park will be part of the daily experience of people living and working in the neighborhood. Walking paths, playgrounds, cafés, a performance venue, and 12 gardens, each representing a different natural environment, form a full-fledged urban park. In addition, a 1,000-foot-long fountain will have jets of water triggered by the movement of buses below. Over time, bridges will be added to connect adjacent buildings to the park, fully integrating it into San Francisco's urban fabric.

As one of the country's greenest buildings, the Transbay Transit Center will use multiple sustainable design strategies. The most visible is the park, which will absorb and filter pollutants through its trees, landscape and water management system. Beneath the Transit Center, a massive geothermal heat exchange system will be built into the building's foundation. Running the length of 4 ½ city blocks, it will be one of the largest geothermal installations in the world. To further reduce energy consumption, the building will be naturally ventilated and most spaces will be naturally lit. Finally, the building will manage stormwater and reuse greywater. The water reuse and conservation system will save 9.2 million gallons per year, the equivalent of 19 Olympic-sized swimming pools. The building is targeted to achieve a Gold LEED rating.

Intended to be a destination for both transit users and the general public, the building will offer street-level shops, cafés and public promenades. In addition, the architecture integrates works by significant contemporary artists including James Carpenter, Julie Chang, Jenny Holzer, and Ned Kahn.

Transbay Tower will join the Golden Gate Bridge and the Transamerica Building as one of the defining images in San Francisco's skyline. The Tower's slender, tapering profile reduces its shadow on surrounding streets and buildings. Its textured mix of metal and glass alleviates excessive glare, minimizing reflections and bright spots. At the street, the tower steps back to allow for wider sidewalks, and a street-scaled canopy runs along Mission and First, protecting pedestrians from downdrafts and lightening the tower's presence. Designed to be environmentally sustainable, the Tower incorporates several green building strategies which may include passive solar shading, high performance glazing, geothermal cooling, and wind power.

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