AUBURN — The City Council voted unanimously Monday in a first reading to allow detached, “in-law” structures to be built in most residential zones in Auburn.

Under current rules, even if a homeowner has the required land area and meets the density requirements, a second unit must be attached or contained within a single structure. The change will allow a second dwelling to be detached from the primary home.

The proposal came as city officials consider a number of zoning amendments intended to encourage housing growth in Auburn.

Those in favor of the proposal have said it would add to the diversification of housing options in the city, possibly freeing up homes for first-time buyers in a market low on inventory.

The Planning Board sent an unanimous positive recommendation on the amendment to the City Council in late March. The change so far does not include the low-density country residential zone, but it could eventually be added, city staff said.

It excludes the agricultural and resource protection zone.

Despite the unanimous vote Monday, councilors said they had heard some concerns from constituents, including whether properties with detached dwellings would be easier to subdivide, especially when sold.

One resident, who wished to remain anonymous, told the Sun Journal she had similar concerns. She also questioned why the council was moving so quickly on its zoning amendments.

“Yes, there is confusion about this new zoning law so why push it through at a time when people are reluctant to gather for fear of the pandemic?” she said. “What’s the big hurry?”

City officials held a public discussion on zoning at the Auburn Senior Community Center last week. About 15 people attended, according to Mayor Jason Levesque.

The meeting was requested by Councilor Holly Lasagna after she said she had heard some confusion from residents about what the changes could mean for them.

Eric Cousens, director of planning and permitting, said the amendment does not change current rules on the ability for homeowners to subdivide. Unless the lot is large enough to split, the two dwellings would be on a single parcel.

“It’s still the same lot of land,” he said, adding that most of the time, road frontage requirements prevent property owners from subdividing.

When asked if there had been discussions on limiting the size of the secondary structure, Cousens said the Planning Board “didn’t see then need to restrict the size,” but said any structure has to meet the setback and maximum lot coverage requirements of the zone in which it is built.

According to the amended zoning language, the ordinance would stipulate that only one “principal building shall be erected” on any lot in residential zoning districts, except “an additional one-family detached dwelling in a zoning district where two-families are permitted and a single-family dwelling unit currently exists on the lot.”

It also stipulates “the additional one-family detached dwelling unit shall share a driveway curb cut with the pre-existing dwelling unless it is determined that another driveway location could provide safer access than the existing driveway.”

Officials have said the addition of secondary dwellings is part of a larger effort to provide more options for property owners.

During his recent “state of the city” address, Levesque called for a substantial increase in housing development — about 2,000 single-family homes — over the next five years, while asking officials to remove regulation barriers and encourage infill development in the downtown.

Infill development is the process of developing vacant or underused parcels within urban areas that are already largely developed.

In September, the City Council agreed in concept to a six-month process to increase the available housing units in the city.

In February, officials expanded Auburn’s form-based code district known as Traditional Downtown Neighborhood to a swath of the downtown and New Auburn, meant to encourage infill development and building rehabilitation.