The Martha’s Vineyard Commission has agreed to pardon a series of unapproved changes to the Wavelengths hair salon building in Edgartown, in light of evidence that the changes were unintentional.

At a well-attended public hearing last week, commissioners heard from building owner Jayne Leaf, along with builders, residents and others who cited various mistakes over the last few years, as plans were adapted for a modular design, leading to a significant increase in square footage on the third floor.

The commission originally approved the project on upper Main street as a development of regional impact (DRI) in 2010, followed by modifications in 2011 and 2014. But the new modular plans never returned for MVC review, and applicants said they had not noticed the changes until the building went up last year.

“I was as shocked as everybody else,” project manager Colin Young said at the hearing Thursday. “In this case, it was just really an unfortunate set of circumstances . . . We made the error, and we are trying to fix it in a way that won’t destroy the building.”

Developers have agreed to a list of 12 requests by the Edgartown planning board, but are not willing to replace third-floor dormers that were mistakenly installed and are larger than the original plans. Other unapproved changes included a reshuffling of windows and doors and an open third-floor porch that was relocated from the rear to the side of the building.

Mr. Young said the plans he sent to the modular construction company had been a variation by architect Chuck Sullivan, who had also designed the originals. Ms. Leaf added that the originals had required a number of corrections to comply with the building code.

General contractor Phil Miller of Miller Starbuck Construction said some of the changes had resulted from new regulations related to elevators, but having multiple designers working on the project had also exacerbated the problem.

Several of Ms. Leaf’s clients spoke on her behalf, calling the situation unfortunate and hoping for a quick resolution. Stacy Wallace of Edgartown further argued that the mixed-use building would help address the Island’s shortage of affordable housing. According to an MVC staff report, one apartment will be sold at a reduced rate to Mr. Young, who is an employee of Ms. Leaf and will manage the future condominium association.

Two members of the Edgartown planning board, Fred Mascolo and Robert Sparks, also spoke in support of the applicants and urged the commission to approve the changes. Mr. Mascolo said before speaking that he was appearing as a private citizen and had recused himself from planning board discussions of the issue because an agent in his real estate business represented Ms. Leaf.

“Would they do that on purpose? I wouldn’t think in a million years, because who would want to have to go through this mess,” said Mr. Mascolo. “These are local year-round people just trying to do better.”

Mr. Sparks said the planning board and MVC hearings had led to the same conclusion, with the applicants taking responsibility for the increased square footage.

Some commissioners were critical of the mistakes. Commissioner Josh Goldstein raised concerns about setting a precedent, but Mr. Mascolo said he did not believe the MVC would have any trouble handling similar applications in the future. Commission chairman Jim Vercruysse agreed, noting that every case is unique.

Some commissioners said they were ready to move on.

“Edgartown sent it back here and wants us to be the hit man,” said commissioner Clarence A. (Trip) Barnes 3rd, agreeing that the project presented a tricky situation. But he added: “I know damned well that this wasn’t a situation that was planned this way . . . . I’ll be damned if I’m going to vote to tear the top of that building off the week before Christmas,” he said.

Commissioner Fred Hancock suggested requiring applicants to remove only the open porch between two dormers, but others thought it would not make much difference.

In the end the commission voted unanimously to approve the project, along with the agreed-on list of requests (excepting the request to rebuild the dormers), and contingent on further oversight by the planning board.

The vote drew applause.