Last week while talking at CUNY, mayoral candidate Joe Lhota proposed an interesting idea for building new affordable housing: close post offices and use the land to build affordable housing.

Now, while the specifics need some work, it’s a good concept.  Publicly-owned land and buildings that are not fully utilized should be re-purposed for better public use,  with much of it used for one of our most pressing needs – affordable housing.  But “public land” is not a one-size-fits-all designation. Jurisdiction might be with the city, state, or federal governments, or one of many public authorities, such as the Port Authority. And within these entities, dozens of different agencies might control the plots, each agency with its own agenda.

It’s difficult for the city to gain control of Federally- or State-owned land. But the next administration can take one very significant step – a comprehensive survey of city-owned underutilized land, followed up by a citywide plan for disposition and development, as ANHD recommended in its report, Real Affordability: Recommendations to Strengthen Affordable Housing Policy. There are several parcels of city-owned land that would be perfect for building affordable housing except for one thing – the parcel isn’t controlled by the city’s department of Housing Preservation and Development. But the next mayor, with the stroke of a pen, can transfer them to HPD’s jurisdiction, an action that can allow for thousands of units of affordable housing. In fact, if just half of all publicly-owned vacant land were re-purposed for affordable housing, we could generate space for over 100,000 more units – and that’s without even rezoning to allow for larger buildings.

In terms of deciding land use, many vacant or under-utilized parcels might be perfect for much-needed schools, parks, firehouses, qood-paying light manufacturing and industrial jobs,or a myriad of other things that the city needs, but are under the jurisdiction of a different city agency with no plans, or even ability, to utilize them. For instance, HPD has title to several small plots of land that would have a very hard time even hosting a small house and are the only green space in the neighborhood. It’s natural to turn these into parks or community gardens. Larger plots of land, which could easily host affordable housing but are owned by other agencies, could be turned over to HPD to develop.

It’s understandable that the Parks Department wants the land it controls for parks, the Sanitation Department wants its land for sanitation garages or waste transfer stations, and the Department of Education wants its land for schools. But we’re all in this together, and it’s often the case that the plot of land controlled by the Department of Education would be better used as a park, while the plot controlled by the Department of Sanitation would better used as a school. And many, many city agencies have large parcels of vacant or underutilized land that could be used to build much-needed affordable housing. Vacant and underutilized land should be developed according to its best use for the public, not which agency happens to control it.

The next administration needs to kick off this comprehensive survey right away, within the first 100 days of the new administration, in order to quickly and efficiently identify new sites for affordable housing. Post offices are an interesting idea, one which may or may not be proper or feasible, but either way, they’re only a small part of the puzzle.  The real challenge lies in determining how best to use an increasingly valuable and dwindling resource – our publicly-owned land.