A curtain and stacked filing cabinets separate math teacher Barbara Healey's seventh-graders from the hallway and the English class next door.

At Middle School North, doors are rare and hollow metal panels stand in the place of classroom walls. The building is a relic of the 1970s, when a concept of connected "open classrooms" gained popularity in school construction nationwide.

Over time, that construction style, with its removable walls and no doors, has been criticized for being noisy, distracting and unsafe.

The building is one of nine elementary and middle schools in the Groveport Madison district that would be razed and replaced with four larger buildings, if voters approve a combined tax levy and bond issue on the May 7 ballot.

Four of the schools to be demolished are "open classroom" style, with partitions, lunch tables and office supplies creating makeshift barriers.

"It's really scary, if you think about it," Healey said of being unable to secure her classroom with a locked door if an intruder entered the building.

Superintendent Garilee Ogden said other district buildings are overcrowded and have aging infrastructure, especially plumbing. At Sedalia Elementary School, about 140 students are in 14 rented classroom trailers. Groveport Elementary School will be 100 years old in 2023.

The 37-year, 4.72-mill levy with the bond issue would raise $83.6 million and would cost homeowners an additional $165 in property taxes for every $100,000 of assessed home value. The money raised would cover 47 percent of the cost of the project to replace buildings.

The Ohio Facilities Construction Commission, a state agency that helps districts with construction projects, would pay the remaining 53 percent.

The bond issue is combined with a permanent 6.10-mill levy that would generate $5.7 million a year for district operations, according to district officials. That levy is a renewal of a five-year levy that voters approved in 2014 -- meaning the owner of a $100,000 home would continue paying about $213 a year.

If approved, the levy and bond issue for Groveport Madison schools would continue construction plans that started in 2014 when voters approved a bond issue for a new high school that opened this year. The $60 million project came in $2 million under budget, but officials said the new building might already require an addition because of increased enrollment throughout the district. The OFCC also paid for 53 percent of that project, meaning its construction had to be based on the enrollment projections of the commission's demographer, Ogden said.

The commission is reviewing Groveport Madison's request for a project amendment, said Melanie Derup, the OFCC chief of planning.

Space beyond what is needed for anticipated enrollment can be added to projects, but only if the construction is paid for with local money, she said.

Canal Winchester

Voters in the Canal Winchester Local School District also will see a tax levy on the May 7 ballot.

The five-year, 12.59-mill levy, if approved, would generate $6.2 million for operations but would not cost any more than homeowners pay now -- about $386 annually per $100,000 of property valuation. The district plans to open a 48,000-square-foot addition to the high school in time for the 2020-21 school year.