Inside the cavernous building at Pier 27, construction workers Tuesday worked on the structure that will eventually welcome cruise ship passengers to San Francisco.

Outside of the glass-and-steel building, city officials gathered Tuesday to celebrate the completion of the first phase of the James R. Herman Cruise Terminal.

“For years and years, this will be the legacy,” Mayor Ed Lee said of the entirety of the project that will include a park and open space on the northern waterfront. “Not just a cruise ship terminal.”

Before the 2.5 acres of open space is put in, and before the first ship drops off passengers on the San Francisco shoreline, the America’s Cup will use the two-story building as a headquarters for the races that will run through this summer and into the fall.

Stephen Barclay, CEO of the America’s Cup, pointed out the San Francisco backdrop that international media and people attending events at the facility will see, including Coit Tower and Telegraph Hill.

Speaking at the event, Board of Supervisors President David Chiu also noted that the cruise ship terminal project is part of a larger revitalization of the waterfront by the Port of San Francisco.

“We are rebuilding what 21st century waterfronts are all about,” Chiu said.

Once the America’s Cup events are complete, the second phase of the project will build the Northeast Wharf Plaza and prepare the building for cruise ship business in 2014. The facility will be able to dock ships up to 1,200 feet long and carrying 2,600 passengers, according to the Mayor’s Office.

When the piers are not in use for cruise ships, the entirety of the space will be available for the public to use.

mbillings@sfexaminer.com