That would be dumb, we should be able to buy more then one house if we have the money, capitalism!
We should also be able to rent out the home... or let Hobo's in... or even get robbed.
Imagine how cool that would be. You decide to leave your elegant armor you smithed at your house on an armor rack (This we need Armor Racks!). Then your headed home as you see someone come out of your house... you kill him and find that armor on his inventory... stupid thief.
This would get annoying, so you could hire a guard, or have a guard dog, or just get your spouse really good at one handed combat, and give them a dagger.