Ancient Roman apartments, called insulae, could reach up to 9 stories, could have running water (fed by nearby aqueducts) and were often owned by the rich and rented out to the poorer roman citizens (from somewhat rich equestrians to pretty poor workers).
In Roman architecture, an insula (Latin for “island”, plural insulae) was one of two things: either a kind of apartment building, or a city block. This article deals with the former definition, that of a type of building.
An insula housed most of the urban citizen population of ancient Rome, including ordinary people of lower- or middle-class status (the plebs) and all but the wealthiest from the upper-middle class (the equites). The term was also used to mean a city block.
The traditional elite and the very wealthy lived in a domus, a large single-family residence, but the two kinds of housing were intermingled in the city and not segregated into separate neighborhoods. The ground-level floor of the insula was used for tabernae, shops and businesses, with the living space upstairs. Like modern apartment buildings, an insula might have a name, usually referring to the owner of the building.