Are you familiar with Community Development Finance Institutions or CDFI? If not, are you aware of any special loans for groups of at risk by helping them gain shelter? Similar but not the same as the Habitat model. Some other resources that are part of this movement is micro finance or micro loans, community loan funds (generally geared towards housing and education but not limited), or it could be offered through a participating CDFI Credit Union. It's about doing well while doing good.
It would be best to talk to a loan officer at a community bank in your neck of the woods.