Insulae

Insulae (singular insula) were multi-story apartment buildings that formed a core part of urban housing in ancient Rome and other cities of the empire. The term insulae is Latin for “islands,” a reflection of their location within densely built city blocks, often bounded by narrow streets on all sides.

Construction typically used brick and concrete, with heavy lower floors and lighter upper floors. Ground floors often housed tabernae, shops or workshops; upper floors contained a maze of small rooms—tenants’ dwellings—arranged around staircases or inner courtyards. Access was usually provided by external wooden stairs on the façade or by a shared interior stairwell. The height of insulae varied, but many reached three to five stories, with some examples rising higher in major cities.

Residents included artisans, shopkeepers, and other urban laborers, while higher floors could be rented by less affluent families or multiple tenants sharing accommodations. Conditions were crowded and sanitation was informal; running water and latrine facilities were limited, and fires could spread rapidly in wooden stairwells and upper floors.

Archaeological remains and ancient writings show insulae as a distinctive feature of city life in Rome and imperial centers such as Ostia and Pompeii. Their design reflects urban density, commercial activity on the street level, and the social stratification of housing in antiquity. Over time, insulae underwent reforms and replacements as cities expanded and regulations evolved.