BELFAST, Maine — City councilors expressed cautious enthusiasm Tuesday night for Front Street Yard’s proposal to expand its footprint on the city waterfront. The caution, councilors explained, was tied to the shipyard’s plan to use city owned land.

The company opened on the waterfront 18 months ago and quickly built five structures, one 55 feet high. Front Street also quickly grew in appeal among boat owners, servicing high-end yachts from around the world. It now employs 97 people.

“We were very busy over the summer,” Front Street president JB Turner told councilors. And as the boating season in New England winds down, all the storage buildings are full, he said.

Earlier in the season, the shipyard encountered customers whose boats were too large to lift out of the water. At the same time, the yard’s current lift doesn’t work well in moving smaller boats from the water.

“We can’t survive on big boats alone,” Turner said.

The solution is to expand by adding a larger lift and constructing another building.

“To create more work and more jobs, we would propose another building,” Turner told councilors.

A larger lift alone, able to lift boats up to 300 metric tons, would not generate enough revenue to pay for itself, he said. The new building would be 140-feet by 160-feet with a ridge height of 61.5 feet.

The expansion would bring 40 more jobs, the company has said.

The company, which occupies waterfront land once owned by Stinson Seafood and some former city land, has little room to add new buildings, Turner said.

Three options emerged: expand an existing building, build on the site of the current Belfast Maskers theater, or — the company’s preferred option — build a new structure on a city-owned parking lot adjacent to the shipyard’s building 4.

“To us, the parking lot makes the most amount of sense,” he said.

In making the pitch for buying or leasing the city-owned lot, Turner noted that 58 of the 97 employees live in Waldo County; the average hourly wage, excluding senior managers, is $19.34 with an annual gross payroll of $4 million; and the company pays 100 percent of the cost of health insurance for employees.

Though he didn’t have exact figures, Turner said the average age of employees is in the late 20s or early 30s.

This year, the company spent $1.5 million with Belfast vendors and another $6 million with other Maine businesses.

In answer to a question from Councilor Eric Sanders, Turner said Front Street has been able to weather the slow economy well. In 2007, boat-building was at “full force,” but once the recession began, construction slowed.

“Instead of paying $18 million for a new boat, they pay $5 million [for a used boat] and put $5 million into it to make it their way,” he said. “If you can do both,” build and retrofit, “it’s a win-win.”

The shipyard has had one yacht in its shop for nearly a year and the owner will pay almost $5 million for the retrofit, Turner said.

Councilors told Turner they were thrilled the company was formed in Belfast, and stressed that it was easy to work with Front Street officials on the contract zoning arrangement that allowed the company to build here.

“This is a great problem to have,” Councilor Mike Hurley said of the need for expansion. But considering changing the status of the city-owned parking lot and the city-owned Maskers theater were big issues.

“Act in haste, repent at leisure,” he said, and noted that decades ago, two city streets were given to private interests in the name of economic development by “the geniuses who sat here,” referring to the council chambers.

But Hurley sounded a conciliatory note: “One way or another, we’ll figure a way to work it out,” he said.

Sanders said there was some concern in the city that the company could grow so large as to change the character of the community.

Councilor Mary Mortier echoed that view, saying that she has been stopped in public by residents who have expressed their concerns about the loss of city property.

Speaking on behalf of the shipyard’s expansion earlier in the meeting, former harbor committee member Mike Stein said that the small parking lot the company wants to buy or lease was built to accommodate the Belfast & Moosehead Lake Railroad which, in the mid 1990s was running an excursion boat from the city-owned Thompson’s wharf. That business no longer exists, he said.

Resident Joanne Boynton, who described herself as a “great fan of the shipyard,” said allowing it “to grow so large that it would dominate the waterfront would be a big mistake.”

City Planner Wayne Marshall said the company’s application to add a new lift would work its way through the harbor committee, planning board and council, with public hearings at each step. If the council agrees to lease or sell land, the application to build also will be heard by city committees.