In a true boarding house, the landlord/owner controls who lives there - each room is rented individually. Individual tenants have zero control over who lives in the next room.
But, yes, if you have a typical shared home, where 4 people get together and rent a home at once, yes, you do have that control (and should have it).
But, yes, if you have a typical shared home, where 4 people get together and rent a home at once, yes, you do have that control (and should have it).