Main Street, Rockland, Maine.

ROCKLAND, Maine — Rockland city councilors have given the green light for a historic preservation commission to form in the small coastal city, which has seen a downtown boom and arts renaissance during the past two decades.

Ann Morris, curator for the Rockland Historical Society, drafted and pushed for the historic preservation ordinance, which calls for creation of the commission, out of a desire to preserve the multitude of architectural styles that she believes gives Rockland its unique charm.

“It’s a way to preserve our history and our architecture, which I think are two of our most important assets in Rockland,” Morris said at the Wednesday night city council meeting where councilors unanimously passed the ordinance.

The seven-member commission will create a guiding historic preservation manual and designate specific landmarks and parts of the city that have historical significance as historic districts. During the designation process, property owners within these areas will be able weigh in, and if more than 50 percent of property owners object, the designation will not go through.

After city councilors approve a designation, property owners within these designated areas who seek to make major changes to their buildings — such as moving a porch or changing out windows — must go before the commission to hear recommendations on how the changes could be made in keeping with the historic nature of the building. But those recommendations will not be mandatory.

Councilor Adam Ackor sponsored the ordinance, and was able to see it pass at his last meeting as a city councilor Wednesday. Ackor did not seek re-election this year.

Ackor said he was happy with the way the ordinance seeks to balance the community’s right to preserve its history with flexibility for property owners.

“Rockland really does have a fascinating history,” Ackor said. “This ordinance is not constrictive, it’s not punitive.”

While property owners within designated historic districts do not have to follow the recommendations given by the commission, they will face a $500 fine if they make permanent changes without going before the commission for a review.

On the other hand, if property owners do take the construction recommendations given by the commission, the ordinance includes a tax incentive that would prevent the changes from increasing the assessed value of the property for three years.

“[It’s] An incentive for someone to go the extra mile,” Ackor said. “Often, that work requires a lot more time and a lot more money.”