PORTSMOUTH — Slamming the door on “big box” development, the Town Council last night banned any retail store larger than 45,000 square feet.

The vote was 4 to 3, with Democrats in the majority, and the council’s two Republicans and an Independent in the minority.

Many residents in the audience favored a limit of 35,000 square feet, including members of Preserve Portsmouth, the citizens’ group that organized resistance to a proposal from the Target department store chain last summer.

Target would have erected a store covering 3.2 acres, or 146,500 square feet, on a 16-acre parcel at Union Street and West Main Road.

Last night, one official made it clear that the limit on building size will not prevent development altogether.

John Borden, chairman of the Design Review Board, said that eventually, there will be 146,000 square feet of retail space at Union Street and West Main Road.

The land is properly zoned, he said, and the percentage of a lot which may be developed has not changed.

Instead of one building covering all that acreage, there will be a few smaller buildings, Borden said.

“I’m in favor of a cap,” Borden said. “From a design viewpoint, it’s a lot easier to put standards on a 25,000-square-foot building than a 146,000-square-foot building.

Hubert E. Little, a Republican council member, failed in an attempt to impose a 35,000-square-foot limit, about 3,000 square feet larger than the town’s largest store, Clements’ Marketplace.

With a 35,000-square-foot ceiling, “you just told Cements’ they can never expand,” said council president Dennis M. Canario.

“I won’t support that.”

Little said no one even knows whether Clements’ wants to expand.

And some residents said the ceiling can always be raised in the future.

But Canario said the market’s needs in another five years can’t be anticipated.

Canario, a Democrat, as well as the council’s other Democrats, vice president James A. Seveney and council members Leonard Katzman and William E. West, voted for the 45,000-square-foot cap.

West said at the outset of the meeting that he favored no restriction on building size, but once it became clear that one was destined to pass, he voted for what he considered the lesser of two evils.

West said the town needs commercial development, particularly on the West side of town, and property owners have a right to realize the profits from their investment in their land.

Seveney said he wanted to ensure that any ceiling on building size did not exclude an investment company, bank, or other company capable of contributing tax revenue to the town and offering high-paying jobs. The language finally adopted applied only to retail development.

“The compelling discussion is this town has not been about big box development but our property taxes and budget,” he said.

A ceiling of 35,000 square feet, or even 40,000 square feet, would “send a clear message to potential developers: don’t bother,” Seveney said.

The message would say “that we’re happy with our property taxes,” he said, despite a special Financial Town Meeting about 18 months ago in which many voters said they were “unhappy with their taxes.”

Voting in the minority with Little were council member Peter J. McIntyre, another Republican, and Karen J. Gleason, an Independent.

Gleason said she wanted to protect the “mom and pop” stores that have done business in town for decades and would be forced to close if larger stores opened.

Gleason expressed sentiment for limiting new stores to a maximum of 25,000 square feet.

But Seveney said the council “can’t be viewed as restraining or constraining fair and open competition.”

Seveney and other Democrats on the council said they believed that a ceiling of 45,000 square feet was large enough to allow expansions of existing businesses but too low to make it economically feasible for a “destination” store to open its doors.

Another amendment to the zoning ordinance enacted last night requires any retail proposal larger than 25,000 square feet to submit a proposal for a “planned unit development” that would have to meet higher tests than previously required.

That new requirement was adopted unanimously.

gmacris@projo.com