The zoning amendment for the lot near Argyle Street and Long Avenue kills the proposed project by developer American Heritage, which was first introduced in 2014. [provided]

A proposal to bring a 48-unit Northwest Side apartment complex that was already on life support is now officially dead after Ald. Jim Gardiner (45) downzoned a vacant Jefferson Park lot this week, undoing a 2016 zoning decision championed by his predecessor.

At a Tuesday meeting, the Committee on Zoning, Landmarks and Building Standards approved the downzoning of the lot at 5330-5338 W. Argyle St., where a 48-unit apartment complex was previously approved under former Ald. John Arena.

The lot is just steps away from the Jefferson Park Blue Line station and Metra stop.

The proposed project by developer American Heritage, first introduced in 2014, was a flashpoint in the 2015 aldermanic election and opened up a fierce debate over whether Jefferson Park should remain a suburban-like haven or allow denser developments near transit hubs and business districts.

The project was never built, and any new pitch for the site would already need to go through City Council process anew. But the decision advanced on Tuesday ensures that the original plan, which scored zoning approval in 2016, will not move forward.

Gardiner sought the downzone because of “very valid concerns” from neighbors about density in a “neighborhood filled with single-family homes and two-flats.”

“Due to the height and density of this building, many neighbors and community groups expressed their valid concerns and the impact such a development would have on our community,” Gardiner said at the meeting.

The lot, which was previously zoned as a multi-unit district, now will only be able to accommodate single-family homes or two-flats, but only if the block is predominantly already made up of two-flats.

In 2016, residents and members from the Jefferson Park Neighborhood Association protested outside of Arena’s office, asking him to reject zoning changes that would allow for the 48-unit development and others in the area on the grounds that they would adversely affect parking, traffic and alter the character of the neighborhood.

Gardiner said the project has been controversial ever since new zoning laws went into effect and asked the committee to approve his request that would be “most palatable to our constituents.”

“It will help ensure the development of single-family homes and two flats as opposed to a large scale project that would have real consequences to residents who have lived in this area for decades,” he said.

The zoning change is set for final approval by the full City Council on Wednesday.