Since we can build a doghouse for Dogmeat, we should have options to allow our favorite companions to either move into our house or offer to build them a house of their own in one of our settlements. This way, when we dismiss them, they're all safe in one place, like the casino strip in New Vegas.
Plus, with weapons and armor we give them, they can pull their weight with town defenses, fending off raiders when we're not around.