Old Lyme — The Region 18 Board of Education has asked for refined cost estimates for three potential building projects that could each cost more than $40 million as it works toward a possible fall referendum in Lyme and Old Lyme.

The projects, first pitched to the school board in November using preliminary estimates from architects with the Farmington-based QA+M firm, start at $41.87 million for basic heating, cooling and accessibility upgrades to the district's preschool, elementary and middle school facilities. The other options, which each come in around $45 million, include the basic upgrades to the four schools plus targeted renovations.

School board members then will have to decide which of the choices, if any, are right for the district after they receive the breakdown of costs. QA+M principal Am'r Rusty Malik said the architecture firm usually takes about two weeks to gather the detailed cost estimates.

Superintendent of Schools Ian Neviaser this week said the school board's next step will be to analyze the results and determine what exactly the school board wants to include and what can be eliminated — and also "to determine if these options are what is best for our schools."

The four buildings — not including the high school — were last renovated 20 years ago, according to Neviaser.

He has said the aging heating and cooling systems triggered the $45,850 facilities analysis the architecture firm was hired to conduct last spring. "No matter what, we have to address HVAC," he told school board members at a special meeting last week. "That's an issue. It's aging. It's inefficient. It needs to be upgraded."

The renovations included in the two other options address a population increase projected by the nonprofit New England School Development Council.

The Region 18 school board has policies identifying class size targets for the different grades. They specify a maximum of 15 students in each kindergarten classroom, 18 in first grade, 20 in second and third grade, and 22 per fifth grade classroom.

Neviaser said the current projections would have the classrooms exceeding capacity in kindergarten through grade five by 2024. Numbers show the target of 570 students could be exceeded by 22 in 2024, by 31 in 2025 and by 58 in 2026. Enrollment projections are created using factors like birth rates, census and housing data, previous enrollments, number of females of childbearing age in the community and other factors, according to Neviaser.

Of the two options involving renovations, one would come in at $45.48 million to expand the middle school to include the Board of Education offices and the district's alternative education programs. It also would reconfigure Center School to add kindergarten to the school's current preschool population.

The other option, which comes in at $45.12 million based on the architect's preliminary estimates, would include a 7,500-square-foot addition to Mile Creek School for more classroom space. It's currently 52,609 square feet, according to the architecture firm.

A suggestion to put a 5,000-square-foot addition on the 35,147-square-foot Lyme Consolidated School was scrapped due to what Neviaser described as a lack of space for an addition.

A suggestion by Republican school board member Christopher Staab to get another opinion on the cost of the base option ultimately was rejected when members were assured by Malik that the firm uses a third-party construction company to come up with the refined cost estimates.

Malik noted there is a possibility of funding coming down from the state for HVAC repairs at schools.

The influential Connecticut Conference of Municipalities is lobbying legislators to fund air filtration improvements and HVAC repairs for schools through state bonds because the advocacy group believes indoor air quality is critical to the health and safety of students, teachers and staff. The upcoming legislative session convenes Feb. 9 and runs through May 4.

"If that happens, the numbers change drastically," Malik said.

Old Lyme resident and previous school board member Steve Cinami during public comment balked at the cost of any of the options. He said the four buildings were renovated 20 years ago, the high school was renovated almost 10 years ago, and now residents need to pay up again — all within two decades.

The Lyme-Old Lyme High School renovation project was completed in 2013 for $35.26 million, according to The Day archives.

"It's certainly something to think about when you're asking a small town like this," Cinami said.

Resident and previous Board of Finance member Anna Reiter said it's important to address air quality in the schools and to make sure the buildings can accommodate all students. "I think you need to make sure there's space for all the students, and that includes increases in enrollment," she said.

A slide presented at last week's school board meeting said the financial impact of the project will hit at the same time the debt currently carried by the district drops by $618,850.

That means a $45 million project introduced in the 2023-24 budget could lead to an overall decrease from the previous year's budget in debt service, according to the district — or it could lead to an increase of $1.53 million over the previous budget year. That all depends on the distribution of borrowing, interest rates and borrowing structure, the district said.

The school board nixed a $44.62 million proposal to renovate Center School and buy an existing building, such as a house on Lyme Street, to convert into the new home of the Board of Education. The board also struck down the $62.69 million possibility of building a brand-new kindergarten through grade five building.

e.regan@theday.com