A building that was once part of New Haven’s largest industrial complex is slated to open next month as the first housing unit in Science Park.

Known as Winchester Lofts, the 158 rental apartments are opening in the abandoned buildings of the Winchester Repeating Arms Company, an American rifle company whose factory occupied 75 acres of land and employed hundreds of New Haven residents for much of the 20th century. Today, those 75 acres are part of Science Park, an area that Yale and the city have jointly worked to redevelop into a business center. Although this area, located just west of Yale’s science hill, now boasts research labs, biotech companies and notable startups such as Higher One, it has yet to see any residential complexes.

Developers said the Winchester Lofts will begin to fill that void, while contributing more generally to the city’s need for more affordable housing.

“We think that doing something productive with the old gun factory building will bring life and energy to that neighborhood,” said Erik Johnson, executive director of the Livable City Initiative — a housing department that has worked with the developers of Winchester Lofts.

Vice President for New Haven and State Affairs Bruce Alexander ’65 added that the lofts will bring in 24-hour activity to Science Park, which so far has only been active during working hours.

The land where the new lofts are located is owned by the Science Park Development Corporation, a nonprofit established in 1981 by the city, Yale and the Olin corporation — the rifle factory’s previous owner. The SPDC’s Board of Directors, on which Alexander sits, manages the nonprofit and can set rules about how the land in Science Park should be developed.

President of the Corporation David Silverstone said the group decided to add a housing unit to Science Park in part to address New Haven’s low vacancy rate — a rate that he said was lower than any other city with a population above 100,000 last year.

“It’s getting harder and harder to find an apartment in New Haven,” Silverstone said. “With its location right near downtown and Yale, we thought this site would be a great opportunity for new housing.”

Silverstone said the Corporation mandated that whoever rented the space now occupied by the Winchester Lofts transform it into a housing unit with approximately 160 units, 20 percent of which should be “affordable,” meaning they would be priced below market value and would reserved for low-income residents.

While city developers applauded the addition of lower-priced housing targeted at low-income families, those lofts have so far been “under-subscribed,” Johnson said. The complex is currently still under renovation, but Forest City Enterprises — the development firm leading the project — has opened a model apartment and a leasing office where potential renters can visit the property and sign a lease. Johnson explained that based on his conversations with the developers, there has been less interest in the affordable housing units than in the unaffordable units.

He did not know exactly how many affordable and unaffordable units have already been leased, but he noted that Newhallville residents have expressed concern over the apartment’s prices, simply because they are unaware that some units are priced below market value.

“There have been comments from some people living in the neighborhood [near Winchester Lofts] that the rents are going to be too high,” Johnson said. “People have not challenged that perception to actually see that there is affordable housing available.”

When the loft development was just beginning in 2013, the News reported that several Newhallville-Dixwell residents expressed discontent about the new lofts, both because of their prices and because the residents felt neglected in the development process. One resident told the News that offering 20 percent of low-priced housing was not enough — she said it should be at least 50 percent.

In addition to putting in place affordable housing, Forest City developers are required to maintain the historic façade or the building through the renovation process because the space is part of a historic district listed on the National Register of Historic Places.

Senior Vice President of Forest City Abe Naperstek said the new building maintains the original site’s “historical character,” for example, by replicating windows, restoring a mural that has been in the building since the 1930s and not putting in place modern construction staples like drop ceilings.

The complex will open in phases, with the first set of lofts opening on Oct. 1 of this year and the final set opening in early January.