A New Jersey housing advocacy group is challenging the affordable housing plans of 16 towns, saying they fall short of what is required by a 2024 law that aims to add 80,000 new homes across the state.

If the nonprofit Fair Share Housing Center’s court challenge succeeds, the towns could be stripped of legal protections and affordable housing developers could sue them to force more housing to be built.

Under the 2024 state law, which went into effect in June, more than 500 municipalities are required to build a set number of affordable homes. The towns are mandated to add between 150 and 1,000 homes between now and 2035, Gothamist reported last year. For towns that comply with the requirement, the law grants them immunity from lawsuits brought by builders and developers who want to construct housing but haven’t received approval.

Montvale, a wealthy town that borders New York, has been among the most resistant to the law. State officials have mandated that the town allow more than 300 new affordable homes to be built there. Montvale — where the median income is about $183,000 a year, nearly double the state average — said it can add four new homes over the decade.

Mayor Mike Ghassali told Gothamist he was not surprised by Fair Share Housing Center’s challenge and he would “100%” fight it. Ghassali is leading a group of local mayors from 28 New Jersey towns that are suing in federal and state court to have the 2024 law overturned. So far, he and the other plaintiffs have been unsuccessful in multiple attempts to get the state’s affordable housing planning process paused while the legal fight plays out.

“My residents want us to fight this. We're fighting it. We are being more than fair,” Ghassali said, adding that Montvale currently has more than 360 affordable units.

The other towns Fair Share Housing Center is asking the courts to take action against are Belmar Borough, East Greenwich Township, Florham Park Borough, Franklin Lakes Borough, Hanover Township, Lyndhurst Township, Madison Borough, North Arlington Borough, Park Ridge Borough, Rockaway Township, Roxbury Township, Saddle River Borough, Summit City, Toms River Township and West Windsor Township.

Mayor Daniel Pronti of North Arlington declined to comment on the center's legal challenge but said, “We are confident that we can work cohesively to prove our existing compliance with the [state’s] mandate."

Mayor Keith Misciagna of Park Ridge Borough called the challenge “very disappointing news.”

“We have and will continue to support reasonable development but will not be bullied into allowing overdevelopment of our community without considering proper established planning practices,” he said.

Gothamist reached out to officials for the other towns but did not receive further comment on the court matters.

Fair Share Housing Center Director Adam Gordon said his group intends to hold each town accountable to build the required housing.

“At the end of the day, this is about ensuring that teachers, nurses, families with young kids, veterans, seniors and people with disabilities can afford to live in the communities they call home,” he said.

According to the nonprofit, 423 towns across the state filed affordable housing plans this year, a record in the 50-year history of the Mount Laurel doctrine, a series of state court decisions requiring every New Jersey municipality to contribute its share of affordable housing.

This article has been updated to include a comment from Mayor Keith Misciagna of Park Ridge Borough.