Apartments (Insula) in Rome
In Rome and Ostia, most commoners could not afford to live in private villas, and instead dwelled in apartment buildings, or Insula. These buildings were usually two or three stories tall, but could be as high as six stories, with the size and quality of the apartments diminishing as one moved up in floors. Shops and businesses often occupied the ground floors. Insula were built and owned by wealthy men, who acted as landlords and put the spaces out for rent, but were also charged with maintaining them (something that, like the owners of tenements in the 19th century, they usually failed to do). Interestingly enough, despite the huge disparity between these landlords and their tenants, Rome was not generally segregated into strictly rich and poor neighborhoods, and insula often stood alongside homes of the wealthy.
Life in these buildings wasn’t super fun - insulae had no running water, toilets cellars, or ovens, which meant that dwellers had to use public fountains, public toilets, and had to buy ready-made food from bakeries or street food sellers. The living quarters were dark, cramped, and unsanitary, and had a high risk of catching fire and even collapsing due to shoddy construction from money-pinching landlords or contractors. Because the insula lacked even the most basic necessities, most people were forced to spend the bulk of their social time outside - on the street, in shops and public baths, or in places of entertainment like the coliseum. [x]