I am looking for suggestions for a word that would describe this living situation: in many Arab countries, multiple generations of families / multiple families live in the same building/house, on separate floors that function as self-contained living units, almost like apartments. They are not quite apartments, though, I think. For example, a mother and father may live on the first floor (A), while one of their sons and his wife and children live on the second (B), and another son and his family live on the third (C), etc. Each of these living spaces has its own bedrooms, kitchen, bathrooms, entrance, etc. They may only be connected by a stairwell.
I don't feel it's accurate to describe B as living "on the second floor," as this implies the family could just walk down the stairs and be in A's living room, for example. It also feels inaccurate to say B lives in a second-floor flat or apartment, because it's all really one family house, just sectioned into individual living spaces.
Any ideas? Sorry for the long description - let me know if this makes sense. Thanks so much!