A ruling from a Superior Court judge delivered on Thursday spells out Princeton's affordable housing obligations. Mercer County Assignment Judge Mary C. Jacobson ruled that towns must meet fair housing needs totaling more than 150,000 units, statewide. Specifically, Princeton must build 753 new affordable housing units by 2025.

The number of required affordable housing units in municipalities statewide has been in dispute, and often in litigation, since 1999. In 2015, authority concerning setting affordable housing requirements for municipalities throughout the state fell on the courts.

This is the third round of affordable housing requirements that have been issued since two court decisions in the 1970s established that municipalities must have an affordable housing aspect to their master plans. In the prior round, Princeton's obligation was set at 641 homes. The judge determined that the current need is 80. The prospective need is 365, and the gap is 388, making for a final number of 753.

Princeton had been arguing that its need should be about 300 units, and joined other Mercer County towns in challenging their legal obligations in court. The decision was announced on Thursday, and a compliance hearing is scheduled for July 24.

Towns that have already reached settlements - including Hamilton, Ewing, Hopewell, Mount Laurel, Woodbridge, Edison, Metuchen, and Bridgewater - have said they would look into redeveloping vacant strip malls, office parks and industrial sites, according to the Fair Share Housing Center. They have also pledged to work with local non-profits seeking to build new homes that will allow people with disabilities to receive the support they need to live near their friends and family.