I ‘volunteered’ once for Habitat for the Homeless (Jimmy Carter’s project), through work. Some observations:
1) Only the ‘adults’ were allowed to use power tools (probably not a bad idea, since I doubt many of the volunteers knew which end of a screwdriver to hold).
2) The houses were tiny, with a small concrete slab for parking (probably around 800 square feet, if that).
3) There were really nice houses across the street.
The last one sickened me so much that I left very quickly, knowing that the people across the street didn’t buy the land and build their houses just to have the Third World show up. Needless to say, the other volunteers there thought the project was the best thing in the world.