Ancient Roman Insula or Insulae
Towards the end of the Republic in Rome and other cities only wealthy Romans could afford to live in private houses. Most citizens lived in apartment buildings and tenement houses called insulae or insula in the singular. Roman insulae were sometimes six or seven stories high. The emperor Augustus restricted their height to seventy feet; Nero, after the great fire of his reign, brought the limit down to sixty feet.
The ancient Roman insula was often built very poorly and cheaply for speculative purposes with Juvenal speaking of the great danger of fire and collapse. Outside rooms were lighted by windows. There were sometimes balconies overhanging the street. These, as the windows, could be closed by wooden shutters. The inner rooms of an insula were lighted by courts if assuming they were lighted at all.
Roman insulae were sometimes sub-divided into apartments of several rooms, but were frequently let out as single rooms. At Ostia remains of insulae were found where each of the upper apartments has its own stairway. The ground floors were regularly occupied by shops or taberna. The superintendent of the building, who looked after it and collected the rents, was a slave of the owner and was called the insularius.