Shut down military bases have some form of housing for troops and their families just sitting empty and rotting away.
Why aren't we boosting the stuttering economies of those cities by hiring contractors to make them habitable and allowing the homeless to put in some sweat equity by painting and fixing up a place for themselves to live?
Why can't our drug and alcohol rehab programs be housed in abandoned barracks?
Cities these abandoned installations are in are starving for people. When you have an influx of people, local service industries have to expand to service them. That means jobs...for the homeless people you've just injected into the community.
We own the land & buildings. There's no massive capital outlay to get this up and running. Let's do this!