WESTPORT — Three months after concerns about pervasive mold closed Coleytown Middle School, options for remediation or a complete rebuild of the school have emerged, and so have each plan’s estimated cost.

The Board of Education hired Mount Kisco based KG+D Architects to investigate what it would take to remediate the building and on Monday, the firm presented three options to the board. The first option — to remove and replace all of the school’s exterior walls and renovate the school’s interior and roof — would cost an estimated $25 million, based on industry standards, KG+D predicts.

The second option is to remove and replace both Coleytown exterior and the HVAC system, and complete renovations similar to those included in option one. This would cost an estimated $35 million, KG+D said. The third, nearly $70 million, option is to demolish the existing school and construct a new one.

“We have much more information than we did before,” BOE Chairman Mark Mathias said, adding the board does not yet know when it will decide on one of the three options.

The BOE has already requested upward of $800,000 for work related to Coleytown this year, all of which the Board of Finance has approved, BOF Chairman Brian Stern said. Next Wednesday, the BOF will vote on whether to appropriate an additional $284,558 for mold remediation, reconstruction, and professional services at Coleytown.

“As a town, we clearly prioritize good education for our kids. It’s an important part of our brand and our community and we will continue to do that. We’ll have a little financial crunch, but we’ll figure it out,” Stern said, noting the $800,000 came out of the town’s general fund.

Top on the agenda is to decide where Coleytown students will attend school in the fall of 2019, Mathias said. For the rest of this school year, Coleytown sixth-graders have been relocated to Bedford Middle School while the seventh- and eighth-grade students are housed at Staples High School.

The board plans to choose a location by mid-December, to give the administration time to create a budget for the 2019-20 school year. The budget is expected to be presented to the BOE by the first week of January, Mathias said.

In the scenario that Coleytown will remain closed for the upcoming school year, the administration will plan to house the displaced students in the seven other Westport schools or in a rented space, Superintendent Colleen Palmer wrote in a letter to district parents Nov. 1. The administration is currently searching for a real estate agent to assist with finding a property the district could rent, Palmer wrote.

A committee, with one representative from several stakeholder groups, including the Representative Town Meeting and Board of Finance, will convene soon to study and provide recommendations for the future of Coleytown and Westport school facilities, Mathias said.

“We have to keep the membership small for expediency right now, but we’ll make sure it’s open to public comment and collaboration,” Mathias said.

In the meantime, the BOE has put out a request for proposals for the addition of six modular classrooms at Bedford Middle School to ease the crowding caused by the addition of Coleytown seventh- and eighth-graders, Palmer wrote. Additional lockers and a revised scheduled have also been put in place at Bedford to better accommodate the Coleytown students at Bedford, she added.

The modulars will likely be installed mid-January, Mathias said. The Board of Education will next meet on Nov. 19.

svaughan@hearstmediact.com; 203-842-2638; @SophieCVaughan1