AMHERST — A zoning change aimed at slowing the development of new apartments and townhomes, especially in neighborhoods close to the University of Massachusetts and where students are most likely to be tenants, is being sought by the Planning Board.

On a recommendation from the Planning Board’s Housing Subcommittee, the board voted 4-1 on Wednesday, with two members absent, to ask the Town Council to begin the process of amending what is known as “Footnote M,” by increasing the square footage required for any additional unit on residential lots from 4,000 square feet to 6,000 square feet.

When “Footnote M” was adopted by Town Meeting in 1993, it was set at 6,000 square feet, but then amended down to the smaller 4,000 square feet in 2005.

“Experience since 2005 is clearly showing that this subtle yet significant change has led to recent proposals to add multiple additional dwellings on single-family lots that both the Local Historic District Commission as well as the Zoning Board of Appeals have rejected as out of character and too dense for the general residence zoning district around the town center,” reads the Housing Subcommittee report from Jan. 31.

Planning Board member Jesse Mager, who is on the subcommittee, said getting more housing for families and year-round residents is a goal of the board.

The worry, though, is that if “Footnote M” remains as it is, and the town no longer able to require that either an accessory dwelling unit or the main home be owner-occupied, neighborhoods will be increasingly inundated with more rental properties.

Planning Board member Karin Winter said the change should be seen as giving town officials more time to plan. “It’s going too fast, it needs to be regulated,” Winter said.

Chairman Douglas Marshall was the only vote against the measure, though members Johanna Neumann and Lawrence Kluttz were not present.

“My objection is I don’t want to be moving in the direction of reducing density in areas where there is high demand for housing,” Marshall said. “I think that’s the wrong direction to move.”

Marshall said it shouldn’t be an issue to have student housing be congregated near the UMass campus. In addition, Marshall said he worries about Amherst trying to stymie housing development when Gov. Maura Healey is pushing for more housing across the state, making it “not a good look” for the town. It’s uncertain whether the move to require larger spaces for additional dwelling units would be challenged under the new state law allowing ADUs by right.

There may also be the unintended consequence of diverting development pressure to other neighborhoods.

Planning Board member Fred Hartwell said going back to the original “Footnote M” would be wise. “It should have not been increased to 4,000 and we can correct that if we take this action now,” Hartwell said.

Scott Merzbach can be reached at smerzbach@gazettenet.com.