An owner-occupier is someone who owns the house or apartment they live in. The home is theirs, and they sleep there. They are not a tenant paying rent to somebody else, and they are not only a landlord whose building is full of other people’s lives — though actually one person can be both: they may live in one flat and rent out another. Housing law, banks, and newspapers like the word because it draws a tidy line: owner-occupiers live in their own places; investors often do not. You will also meet the adjective owner-occupied for the building itself: an owner-occupied house is lived in by the people who own it, not let out. In everyday talk people often skip the long word and just say they own their place. The idea still matters in money talk, because governments and lenders sometimes treat owner-occupiers differently from landlords.