Simple rules for character homes.

1. Live within your means. If your known as the King in Rags or something, your not going to be living in a big fancy house. Unless it's a clever cover.
2. Multiple characters can share a home, within reason. Five people in a tiny apartment doesn't really work, besides with five people you should be able to pool resources to afford a bigger place.
3. Items and weapons of various kinds can be stored here, obviously, just watch out if the police come knocking. They'll ask you about that bazooka.
4. Feel free to put traps in your house, if your that kind of crazy and/or paranoid.
5. Try to be realistic. Weird houses are fine to a degree, like living in a ventilated underground bunker, but try for a floating mansion above the city and you'll fall pretty quick.

That's pretty much it, the rest is free reign until someone breaks a rule I didn't think of.