Three months after the city told her she could start, then made her stop, Kathe Alkoudsi finally can finish building her new garage.

“You can’t imagine how frustrating it’s been,” she said Tuesday.

The Lawrence City Commission on Tuesday gave Alkoudsi permission to proceed with construction at 1344 Mass. That’s even though the Historic Resources Commission determined in June the garage will “encroach upon” the environs of the nearby Castle Tea Room, 1307, which is on the National Register of Historic Places.

That decision came after the city’s Neighborhood Resources Department issued a building permit to Alkoudsi, not realizing that its proximity to the tea room  within 500 feet  required it to go through the historic review process. City officials put a stop to construction once they realized the error.

The unfinished building sat under plastic coverings for most of the summer.

“This is a half-completed building,” Bradley Finkeldei, Alkoudsi’s attorney, told the city commission Tuesday. “About $19,000 of my client’s money is in this building. There is no feasible and prudent alternative to letting this go forward. Anything else is economic waste.”

Commissioners agreed.

“I think this is unique,” Commissioner Mike Rundle said. “We made an honest mistake.”

The garage, which will hold costumes Alkoudsi buys and sells, still has some hurdles. Commissioners said the design still must be approved by the city’s Architectural Review Committee to help it conform to the neighborhood’s design. Anticipated changes will make it look less like a small house, like in the original design, and more like the utilitarian building it is, said Dennis Enslinger, the city’s historical resources administrator.

But because construction already has started, officials say, there’s only so much that committee can do.

“It’s much easier to enforce these standards when you’re starting from scratch,” Rundle said.

Alkoudsi was left less than enamored with city processes.

“I think they’re totally lacking,” she said. “Five hundred feet is one-tenth of a mile, but it allows citizens of Lawrence to be trod all over.”