"Hjem" is equivalent to "home" in english. "Hus" is slightly more complicated. Technically it is any building with walls and a roof, but in general we use it for describing a house someone can live in. But adding to it, we also have "rådshus", "sykehus" etc. I as a native Norwegian would eg never call a shopping mal for a "hus". I would use "bygning" or just say "kjøpesenter" which is the norwegian word for shopping mall.