SOUTH PORTLAND — The South Portland Historical Society wants to expand its headquarters in Bug Light Park to better accommodate featured exhibits, student field trips, busloads of tourists and lectures on the city’s rich history as a World War II shipbuilding center.

The City Council embraced the idea during a workshop Monday evening, when Executive Director Kathy DiPhilippo pitched a proposal to lease an additional half-acre from the city so the society could build an addition to the brick Italianate-style house that has been its home since 2009.

The Cushing’s Point Museum was a significant improvement over the society’s former home in the basement of City Hall, but its tiny rooms typical of circa 1900 construction proved challenging from the start, DiPhilippo said.

“Our building is too small,” DiPhilippo said. “This has been a problem since Day 1.”

Its cramped first-floor display space greatly limits the size and scope of exhibits, requires students to pass through quickly in small groups and prevents 50-seat tour buses from stopping at all, she said. There’s also no room for lectures, offices and other workspaces upstairs are crowded, and archival storage space is filling up fast.

“The photographs, documents, textiles and other artifacts take up a lot of shelf space and we are already being creative to fit things in our space,” DiPhilippo said.

The Portland Pipe Line Corp. gave the house to the society in 2008 and the building was moved from nearby Madison Street to the city-owned park a year later. The society leases the site from the city for $1 per year under a 99-year agreement.

Formerly federal property, the parcel sought by the society is at the far end of the park’s boat ramp area. It’s mostly covered by a concrete slab that used to be the foundation of a Naval Reserve building, DiPhilippo said. The parcel is rarely used, she said, except for overflow parking of boat trailers a few days each summer during special events.

If the council agreed to allow the society’s proposed expansion, the city would have to seek permission from the U.S. Secretary of the Interior to change the use of that parcel, said City Manager Scott Morelli.

All six councilors at Monday’s meeting expressed strong support for the society’s proposal as an opportunity to promote the city’s history and one of its most popular recreational areas. Named for its lighthouse, the 9-acre park on Casco Bay is where shipyards employed 30,000 people building Liberty Ships during World War II.

“I’m in favor of highlighting our amazing history here in South Portland,” said Mayor Patti Smith. “Having an expansion of the historical society would only bring more people to the park.”

Smith said she hopes municipal staff members will be able to work out legal details of the society’s proposal and have it back before the council for a vote in July. DiPhilippo said she’s not sure how much the expansion might cost, but she’d like to kick off the fundraising this fall and have it wrapped up within two years.

The addition would include a multi-purpose gathering space that could seat 100 people for lectures and accommodate 50 people for exhibits, DiPhilippo said. The project also would provide additional archival storage space, parking and possibly public toilets that would be accessible to park visitors, she said.

Russ Lunt, one of the society’s 500 members, told the council that he supports the expansion 100 percent.

“There’s so much history down there,” Lunt said. “It’s a total gem.”