The de Blasio administration plans to sell New York City Housing Authority unused air rights to developers for the first time, the mayor announced Wednesday as part the latest effort to bring the city's crumbling public housing into a state of good repair.

The air rights sale is part of Mayor Bill de Blasio's NYCHA 2.0 plan, which also calls for developing predominately market-rate housing on underused public housing land, prioritizing some of the most pressing capital needs including mold, broken elevators and heating.

City Hall appeared to marshal considerable political backing for the plan, which would take a decade to fully realize. City Council Speaker Corey Johnson and several of his colleagues expressed support along with nonprofit groups involved with affordable housing issues.

Many people, however, still oppose developing market-rate housing on NYCHA land. Councilman Ben Kallos, for example, provided a statement of support even while positing that the new project should be 100% affordable—a scenario that would provide virtually no money for capital improvements.

The politics around infill development are part of what doomed a Bloomberg-era idea to build mostly market-rate housing on open spaces and parking lots. Although the de Blasio administration pledged to prioritize affordable housing in its first NYCHA plan, City Hall has come around to the hard math facing public housing and its dire need for cash.

The buildings developers would construct in part from the purchased air rights are expected to be mostly market-rate but subject to the city's Mandatory Inclusionary Housing policy, which requires at least a quarter of the units to be enrolled in the city's affordable housing programs at varying rent levels.

Proceeds from the buildings—which likely would take the form of a long-term ground lease—would fund repairs at neighboring complexes.

"The money stays in the community, where people need the help and support," de Blasio said Wednesday.

Selling air rights and allowing development will together bring in about $3 billion. When coupled with a plan announced last month to enlist private developers to manage tens of thousands of apartments and $8 billion in expected federal funding, however, the mayor said NYCHA would be able to make nearly $24 billion worth of repairs, or around three-quarters of its current total need.