Following unanimous agreement over a change in zoning designations, the New Haven Board of Alders officially set into motion a project to redevelop 87 Union St. — a parcel of land just southeast of the train tracks ­— into a central residential and retail complex.

Developer Noel Petra first presented the project — which aims to bring 300 apartments, garage parking spaces and retail to the edge of Wooster Square — to the City Plan Commission in mid-September. Late last month, the Board of Alders then agreed to change the zoning designation of the site from a warehouse district to a central residential and retail area. This decision, which allows for mixed-use development in the area, marks the final city approval Petra needed to get started on the project.

“I think the public was very positive in having that building go in,” said Ward 10 Alder Anna Festa. “I don’t think it took a lot for everyone to agree that it was right.”

Petra intends to replace the current warehouses with a variety of residential spaces, including apartments and townhouses, as well as retail and studio space. The new business spaces are set to extend along Olive Street and Union Avenue.

The alders voted to classify the site of the new development to be “BD-1,” signifying the area’s capacity to accommodate a larger population and bigger buildings.

This decision comes in addition to another project, launched earlier in the year, revamping the old Comcast building at Chapel Street between Olive and Union on the western edge of Wooster Square.

Matt Nemerson SOM ’81, the city’s economic development administrator, said the board’s approval of these projects would ultimately help connect Wooster Square to the downtown area. He added that the project would bring in market-rate, unsubsidized apartments.

“We are trying to be consistent — we have been working with the developers for the last five to six months to create this transitional zone,” said Nemerson.

Both Festa and Nemerson underscored the project’s importance in making Wooster Square a more walkable, safe community.

In anticipation of the vote to change the zoning designation, the alders solicited public opinion by holding community team management meetings to gauge neighborhood concerns.

Cathy Hill Conlin, a realtor at Seabury Hill Realtors in Wooster Square, said she thinks that there is currently a lack of upscale apartments in New Haven — a hole that the new development will help fill.

Although Festa and Nemerson emphasized the surrounding neighborhood’s support for the project, Conlin said community members might be less enthusiastic. Developers, she said, should be sensitive to the disruption of surrounding communities.

“New Haven is hot right now, but [the developers] have to be careful,” Conlin said.