SOUTH PORTLAND — The school district will consider the possibility of building a new, consolidated middle school to satisfy state officials who want to address major deficiencies at both of the city’s aging middle schools.

Where a consolidated middle school would be built remains to be determined, but the estimated $23 million cost would be funded entirely by the state, district officials said at a community forum Wednesday night.

The district also will consider the cost and logistics of renovating Mahoney and Memorial middle schools separately as part of a “new vs. renovation” building analysis that’s required to get state funding.

Officials at the Maine Department of Education want to meet the needs of all middle school students in the city, said Michael Johanning, a senior architect with WBRC Architects-Engineers, the firm working on the project.

“The state is going to require us to look at both middle schools,” Johanning said. “The state would prefer we address as many issues as possible with the middle schools.”

Johanning said state funding is available to renovate Mahoney, build a new school for Mahoney students or build a new consolidated school for all South Portland students in grades 6 through 8.

City taxpayers would have to foot the bill to renovate Memorial, build a new school for Memorial students, or include any features in a middle school that are beyond state guidelines, such as larger classrooms or green enhancements, he said.

While the project’s potential cost is unknown, Superintendent Ken Kunin noted that the average size of a new school in Maine is about 160 square feet per student and the going rate for new-school construction in Maine is about $200 per square foot. That would translate to a $23 million school to house the city’s 725 students.

District officials hosted Wednesday’s forum at the high school to explain the lengthy process that lies ahead since the Maine State Board of Education voted unanimously in August to put Mahoney on a list of projects approved for state funding.

The building analysis is the fifth of 21 steps, including construction, that could take as long as six years to complete, Johanning said. The district will hold additional forums to figure out whether to renovate or build a new school, then develop a concept, hold a community straw vote and seek state board approval before holding a citywide referendum on the chosen design.

The Middle School Facilities Committee has already visited two new middle schools in Greater Portland to get ideas: in Scarborough, which was locally funded, and in Westbrook, which was largely state funded, Johanning said.

Johanning presented rough concept designs for renovations to Mahoney and Memorial. Mahoney’s shows an added gym, office space, parking area and driveway from Highland Avenue that would consume all of its ball field space. Memorial’s shows construction of a whole new wing to accommodate myriad design flaws in the existing building.

While it’s unlikely that Mahoney’s site could accommodate a consolidated middle school, Memorial’s site could, Johanning said. An assessment of possible construction sites in the city would follow the building analysis.

Mahoney, built in 1922 as the city’s high school, was rated No. 14 on a prioritized statewide list of proposed school construction projects that applied for funding in 2010-2011. Memorial Middle School, built in 1967, was rated No. 55 on that list.

Mahoney serves about 325 students and sits on 15 acres at Ocean Street and Broadway, near Mill Creek Park. Memorial serves about 400 students and sits on 17 acres at 120 Wescott Road, in the Thornton Heights neighborhood.

While Mahoney is architecturally striking and historically important, both buildings have significant structural, health, safety and handicapped-access deficiencies, along with asbestos throughout and inadequate heating, ventilation, plumbing, electrical and communication systems.

A “thinking together” session of small-group discussions was held after Wednesday’s forum to begin a wider community dialogue on the project. About 70 parents and others participated.

Some parents raised concerns about maintaining smaller middle schools to serve neighborhoods. But while many students can walk to Mahoney, on the east side of the city, many students must be bused to Memorial, on the west side of the city, said Megan Welter, Memorial’s principal.

Matt McAleney, father of a third-grader and a kindergartener at Brown Elementary School, said his kids are the third generation of his family to attend the city’s schools, and his father attended Mahoney when it was the high school.

“I want to see what’s the best option for my kids and for future generations,” McAleney said.

Jamie Keene, mother of a fifth-grader and a second-grader, said she attended the forum to learn about the future development of the city’s schools.

“They did a great job with the high school,” she said. “I’d like to see them do the same for the middle schools.”