Pelli Clarke Pelli has unveiled new designs for the proposed Transbay Transit Center and Park in US.
Construction of the facility will begin in August this year, with the first phase of the project costing of $1.6bn.
The project will include the building of a ground train box, which received $400m in federal stimulus funds.
The glass-and-steel structure will serve 12 transit systems and features a 5.4-acre rooftop urban park with an outdoor amphitheatre, children's playground, public artworks and a lily pond among 20 other sub-environments.
The Transit Center will meet the LEED Gold level standards with its sustainable features.
A geothermal system will reduce energy consumption and a greywater recycling system will manage waste water in the naturally ventilated facility.
The second phase of the project, scheduled for completion later this decade, will offer rail access to the new transit centre via an underground tunnel from the existing rail terminal at 4th and King Streets.
A temporary terminal facility has been under construction since December 2008, will serve the current transit operators.
The new Transit Center is scheduled to open in 2017.