STATE HOUSE NEWS SERVICE

Without increases in fees or taxes or additional state funding, operators of the Boston Convention and Exhibition Center, already the largest building in New England, plan to add 1.3 million square feet to the facility.

Situated in the burgeoning South Boston Seaport area, the hangar-shaped BCEC currently has 2.1 million square feet of space, including a 516,000 square-foot exhibition floor.

The expansion plans envisioned under legislation filed Wednesday run in tandem with the Massachusetts Convention Center Authority’s development of two hotels, Aloft and Element, next door to the BCEC, and the authority is working with the Massachusetts Port Authority on a project to create a much larger “headquarters” hotel above Interstate 90 across the street from the BCEC.

Fees from the 510 new Aloft and Element hotel rooms and the planned 1,200 to 1,500 rooms in the headquarters hotel would buttress the state’s Convention Center Fund, which would fund the $1.1 billion expansion without increases in tourism-based fees and taxes, according to the MCCA.

The legislation authorizes the state to borrow $1.1 billion at a time when transportation infrastructure has been at the top of the agenda for many lawmakers’ state spending priorities. Borrowing for the project would not affect state government’s borrowing capacity because it would be repaid with convention center fund revenues, according to an authority official.

“I am proud to co-sponsor this legislation, not only because it offers an innovative way to fund this project, but for the long-term benefit it will bring to the entire First Suffolk Senate District, the city of Boston and the Commonwealth of Massachusetts,” Sen. Linda Dorcena Forry, who represents the area where the expansion would occur, said in a statement.

The Dorchester Democrat who earlier this year won a special election to succeed former Sen. Jack Hart of South Boston, filed legislation allowing for the expansion with Rep. Nick Collins, a South Boston Democrat who lost to Forry in the special election primary.

Enabled by legislation in 1997 when the South Boston Seaport was populated by parking lots, the BCEC opened in 2004 and now sits in Boston’s Innovation District, overlooking Big Dig infrastructure, the Institute of Contemporary Art, and the future site of Vertex Pharmaceuticals.

MCCA officials hope that by increasing convention floor space, from 516,000 to about 851,000 square feet, and adding a second, larger ballroom, along with the new hotels, Boston can crack into the top tier of convention cities.

The expansion is scaled-down from earlier plans, which included a proposed 5,000-seat auditorium and an addition of more floor space, an MCCA official said. When it opened in 2004, the BCEC was smaller than originally planned.

The expansion would eat up parking behind the building, and the MCCA plans to build a parking garage next to the two mid-sized hotels.

State Department of Transportation officials have said that the South Boston Waterfront will need upgrades in its transportation system, as the expansion of the Silver Line has driven development, such as the Vertex headquarters.

The MCCA anticipates the new Loft and Element hotels to open in late 2015. The larger, headquarters hotel would be “one of the largest hotel projects in the nation,” and would generate more than $25 million annually in city and state tax revenue, according to the MCCA.