Center to include a massive geothermal installation.

Construction for the Transbay Transit Center, San Francisco's new state-of-the-art, multi-modal transportation hub designed by Pelli Clarke Pelli Architects recently began with a groundbreaking ceremony. Scheduled to open in 2017, this landmark glass-and-steel structure will connect the city and the Bay Area via 11 public transit systems.  

Notably, the Transbay Transit Center will be the San Francisco station for California High Speed Rail and the first new high-speed rail station in the United States. Conceived as "the Grand Central of the West," the building is designed in the spirit of the great train stations of the world. The highly sustainable and accessible building is distinguished by dramatic light-filled spaces and a 5.4-acre rooftop park.

"We are very proud of our design for the Transbay Transit Center," says Cesar Pelli, senior principal of Pelli Clarke Pelli Architects, whose winning design was selected in an international competition in 2007. "This will be a beautiful, functional and sustainable building for San Francisco."

It is hoped that the project, which is being built on the site of the Transbay Terminal at First and Mission streets, also will spur development in the surrounding city blocks and anchor a new neighborhood.

"We are very excited about the civic mission of the Transbay project," says Fred Clarke, senior principal of Pelli Clarke Pelli Architects. "We want this to be a great transit center – one by which the city is perceived – but it must also be a great neighbor."

The Transbay 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.

A varied place offering both activity and quiet relaxation, the park will be part of the daily experience of people living and working in the neighborhood. Walking paths, playgrounds, cafes, a 1,000-person performance venue and 12 gardens, each representing a different natural environment, will 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 4.5 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, cafes and public promenades. In addition, the architecture integrates works by significant contemporary artists including James Carpenter, Julie Chang, Jenny Holzer, and Ned Kahn.