Ooh, then I've got work to do. I just put my test family in Newcrest, since it's already empty. I'm also a bit confused about the whole set household income thing. Is that the same as setting family funds, or is there a way to actually change the income level? It's related to not getting bills. I don't use many cheats, so I'm not too sure about this.
As I mentioned before, I don't have GT, JA, or OR, so I'm just doing a test run right now. I'm also doing aliens crashed on Maxis-earth post apocalypse, so it's actually fairly easy to do the same outfit for everyone rule. Aliens default to their suits, anyway. And I'll keep the cave basement in mind for when I actually do the challenge for real. Right now my test family is pretty happy with their roof over their heads setup. They don't even mind swimming in the pool when ti's cold. XD ...well, mostly. My first toddler just became a child, so I'll get to see how the school thing will play out.
...on second thought, I think I'll start my test over. Just for the sake of clarification for my own understanding: town here is defined as an area, such as Newcrest, Willow Creek, and so on? As opposed to the entire game world? I've always referred to those as neighborhoods-a collection of places you can go without seeing a world select screen.
ETA: OK I just stumbled on this by accident while building my new test file's cave/pool. You can have a room-at least a basement-built partially underground. I don't think I can use either this way. Maybe it's meant for fountains.