Mayor Zohran Mamdani is advancing his commitment to affordable housing with this new project.
During a housing crisis in New York City, there are thousands of city-run apartments sitting empty and the number has grown since 7 On Your Side started tracking the problem.
New York City has the lowest vacancy rate of any major city in America.
Despite the announcement, Mamdani has come under fire for continuing to fight against a popular housing voucher program the City Council voted to expand.
Rents in Manhattan and Brooklyn reportedly soared to an all-time high last month.
ADUs, sometimes called granny flats, can be basement apartments, attic conversions, an attached addition, a detached backyard unit, or a converted garage.