The most applause-worthy piece of Mayor Bill de Blasio’s Housing 2.0 report is not the notion that he’s on track to reach his initial housing goal two years early, although protecting or building 200,000 units of affordable housing certainly is an important step.

And it wasn’t even the new goal — to reach 300,000 total units by 2026.

Instead, the best part was the introduction of a new $275 million public-private fund that will allow NYC to provide money to nonprofit and community organizations so they can buy rent-regulated buildings to keep them affordable.

By City Hall’s estimates, the program, called Neighborhood Pillars, should preserve about 1,000 units of affordable housing each year, 7,500 units total. That’s a small dent, but it’s the concept that’s worth watching. If Pillars succeeds, it could be a model for more partnerships with community organizations to address affordable housing development and preservation. It also could take buildings out of the hands of bad landlords or those looking for ways to end their rent-regulation status.

None of this supplants the continued need for new housing construction. De Blasio has long touted his housing numbers without emphasizing the vast majority are existing units. There’s nothing wrong with protecting affordable units, but the new construction part of the plan doesn’t go far enough. Even de Blasio’s new effort to build so-called “tiny” homes on vacant infill parcels alone won’t do much to meet the need.

De Blasio must focus more attention on the need for new truly affordable housing, through rezoning or other efforts. For that, he needs the City Council to be a full partner. Unfortunately, its members often have been lukewarm at best to his initiatives, especially when a high-quality rezoning plan comes to their neighborhoods. It’s up to individual council members to balance the needs of their districts with the broader needs of the tens of thousands of residents who can’t find an affordable place to live.

De Blasio is right to push his affordable housing goalposts further down the field, but real success will come only if everyone plays a role.