It's not exactly as if its a new idea. In parts of the world you occasionally come across very old homes that were originally designed to be shared by humans and animals. Wiki has a whole article on
housebarns if you're that interested. The ground floor was designed as a barn for the half dozen or so cows, goats, sheep or whatever that the family owned, while the people lived above. But they stopped building houses like that about the time they stopped building houses with toilets. After all who wants to go to sleep in a house smelling of shit and wet goats, wake up in a house smelling of shit, and have to put on boots and wade through shit just to get outside. Let alone modern day problems of getting alpace shit on your playstation, your stuffie collection and your selection of dilators and dildos.