The Minneapolis City Council on Friday voted unanimously to allow duplexes and triplexes in low-density residential neighborhoods, eliminating single-family zoning that had been in place for decades.

The vote sets into motion the first and most contentious component of the 2040 Comprehensive Plan, one that drew nationwide attention from other cities looking to diversify neighborhoods as their populations grow.

Before the vote, City Council President Lisa Bender said the approval was “one of the many changes that will be coming” as a result of the plan, which was formally adopted last month.

“We think that we should allow more housing units in every neighborhood, that we shouldn’t cordon off parts our of city to say, ‘This is only for one type of living,’ ” she said. “That we need a diversity of housing types and options, everywhere.”

The change eliminates the “single-family district” category from the city’s zoning districts. New triplexes would still have to follow the same height, setback and building requirements of single-family homes and duplexes.

Council Member Lisa Goodman attempted to assuage residents surprised by the change, saying the council was codifying something it had already discussed at length last year.

“I like to refer to it as, ‘the box can’t change,’ ” she said. “All that can change is how many families can live within the existing box.”

The elimination of single-family districts was the most controversial component of the 2040 plan, with many residents and some council members worrying the change would lead to developers buying up and razing single-family homes. While the plan originally sought to allow the construction of fourplexes, it was later scaled back to allow only up to three-unit buildings in each lot.

Council Member Phillipe Cunningham, who represents north Minneapolis neighborhoods with lower-priced single-family homes, said many of his constituents had a “fear of there not being enough safeguards in place to prevent harm being done as a result of this change.” He said he would work to make sure that allowing the construction of triplexes brings about a positive outcome.

The change will go into effect Jan. 1. Bender previously said she expects there to be a period of time before homeowners seek to convert properties into duplexes or triplexes.

Moving forward, the council will take on other components of the plan, including rezoning across the city and the requirement of affordable housing units on new residential buildings.