Roman insulae: Deadly risks of living in an ancient apartment building

Insulae were multi-story apartment buildings that housed the majority of Rome’s urban population.

The term insula originally meant ‘island’, as these apartment blocks stood isolated between streets, like islands. This was in contrast to the domus, a private kind of house that was reserved for the elite.

Since Rome’s expanding population required efficient housing solutions, insulae became an essential feature of the city’s infrastructure.

Many were primarily for rental purposes, which meant that landlords often prioritized profit over safety.

According to the 4th-century Regionary Catalogues document, Rome had 46,602 insulae compared to 1797 private houses.

Most of Rome’s lower and middle-class citizens would have lived in insulae.

This included shopkeepers, craftsmen, and laborers. Although, minor officials sometimes occupied the better rooms on lower floors.

For those with some disposable income, they could pay for a kind of insula with cenacula, which were self-contained apartments with basic furnishings.

The poorest individuals lived in cubicula. These were small, single-room units without proper ventilation, which meant that smoke and odors lingered in the air.

Therefore, a prosperous artisan might live on the second floor, a struggling cloth-dyer’s family on the third, and day-laborers in the garret above.

This curious vertical social mix meant that insula dwellers were acutely aware of their status relative to others in the same building.

Frequently, tenants moved houses and apartments based on rent prices and employment opportunities.

Wealthier Romans who relied on urban trade and services depended on the labor of those living in insulae. 

Most insulae ranged between four and six storeys in height. Some did exceed eight, which made them among the tallest residential structures in the ancient world.

However, these became quite dangerous, so the Lex Iulia Municipalis in 20 BCE restricted the height of new buildings to 70 Roman feet, which is approximately 21 meters.

Earlier constructions often surpassed this limit and increased the risk of collapse.

While builders had relied on brick-faced concrete for the exterior walls on the lower levels due to its durability, the upper levels were often constructed from timber and mudbrick.

This reduced the weight of the upper floors, but it also made the structure increasingly vulnerable to fires.  

Because lower floors provided greater stability and easier access to the street, they were reserved for wealthier tenants.

Rooms on these levels were larger and better maintained. Ground floors also housed tabernae, which were small shops or businesses that opened directly onto the street.

This meant that commerce and residential life existed within the same space for these wealthy families.

Some insulae even included shared amenities like a well or fountain in the courtyard, and occasionally even a small shrine or temple room.

For example, one Ostian insula, the House of the Charioteers, had a cult room dedicated to the god Serapis on its courtyard.

Those on the upper levels had to use a single staircase that was often very narrow and steep.

As such, rental prices decreased with elevation, which meant that lower levels were more desirable but significantly more expensive.

Many were built on unstable foundations, which caused walls to crack under their own weight.

What is more, heavy rainfall or seismic activity could easily weaken the mudbrick and timber supports, which made collapses more common.

In one of his letters, Cicero notes that several of his rental buildings had collapsed or were nearly on the verge of doing so.

Such incidents were common in Republican Rome, where “most of the buildings are held up by flimsy bits of wood”, as the satirist Juvenal put it.

However, the greatest concern was fire, especially in the packed Subura district.

The use of oil lamps, open flames, and wooden flooring created the perfect conditions for deadly fires.

Once lit, they would spread rapidly in the tightly packed neighborhoods of the city.

In fact, the Great Fire of Rome of 64 CE consumed entire districts filled with insulae.

When an insula collapsed or was burned, the wealthy owners could generally absorb the loss or rebuild, whereas the inhabitants of the buildings lost everything.

Roman law did allow tenants to terminate a lease if the building became unsafe, and landlords could be liable for damages if gross negligence was proven, but such accountability was rare in practice.

Unsurprisingly, almost no insula structures from the Republican era survive to the present day.

The most in-tact remains can still be found in the port city of Ostia. However, one remarkable survivor is the Insula dell’Ara Coeli on the Capitoline Hill in Rome itself.

It was discovered in the 20th century beneath a medieval church, and retains parts of its brick façade.

It stands three and four stories high and dates to the 2nd century CE. It likely had ground-floor shops with multiple levels of apartments above, built around a courtyard (though only a portion of the structure is preserved).

The Ara Coeli insula’s remains, with windows and beam sockets still visible in the masonry, actually confirm many of the ancient descriptions of tall, crowded Roman apartment blocks.

Also, archaeological surveys in other parts of Rome (such as the Esquiline and Subura districts) have uncovered foundations of insulae and their tabernae.

It’s estimated that 90–95% of the people of Ostia, a nearby port city of Rome, lived in insula apartments.

Most historians believe that this would have been similar in Rome itself. So, the daily experience of living in an insula could vary depending on where you were located.

The larger cenacula provided multiple rooms, including a separate sleeping area, a small cooking space, and sometimes even direct access to a shared courtyard.

In contrast, upper floors would provide multiple single-room dwellings that provided little protection from the elements.

Cracks in the walls and gaps in the wooden flooring allowed cold drafts to creep in during winter. 

Overcrowding remained a constant challenge. Many families shared their rooms with extended relatives, apprentices, or even unrelated lodgers.

Because thin walls and wooden floors carried sound easily, privacy became impossible, which meant that arguments, conversations, and the sounds of daily activities carried through the insula.

At night, tenants often struggled to sleep through the noise of crying infants, barking dogs, and the shouts of vendors closing their shops. 

Because insulae generated steady income for their owners, landlords controlled a lucrative market, which meant that they could demand high rents while neglecting necessary repairs.

Wealthy investors such as Marcus Licinius Crassus, who was one of Rome’s richest men, owned multiple insulae.

In fact, the income could be quite substantial for others like Cicero, who bragged that just two of his rental blocks on the Aventine brought in enough revenue to fund his son’s education.

These landlords, though, rarely lived in their properties, which meant that they relied upon people called insularii, building managers, to collect rent and handle tenant disputes.

Unfortunately, because Rome lacked formal tenant protections, landlords could increase rent arbitrarily, and, as such, evictions for non-payment were not uncommon.

The poet Martial describes one poor tenant’s belongings being seized and carried off when he had fallen two years behind on rent, leaving him destitute in the streets.

Due to the lack of direct plumbing in most insulae, residents depended on public fountains for their daily water supply.

This would have required frequent trips through the crowded streets. The fountains were connected to Rome’s extensive aquaeductus, which provided a continuous flow of fresh water.

From the fountains, water carriers transported large clay amphorae of water to the apartments.

Meanwhile, some wealthier tenants in lower floors had access to private cisternae, which collected rainwater, but these were rare and required frequent maintenance.

This led to a reliance on street vendors selling water by the jug, which increased costs for families already burdened by high rents. 

As a consequence of limited sanitation facilities, shared latrinae became essential.

These communal toilets, which were often located on the ground floor or in nearby alleys, consisted of simple stone or wooden benches with openings over a drainage channel.

Residents living on upper floors rarely had access to latrines and relied on chamber pots.

Once full of waste, they were emptied onto the streets or into cesspits. Following this, waste flowed through open gutters that ran alongside roads, which polluted the air and attracted vermin. 

Thanks to Rome’s cloaca maxima, which was one of the earliest known sewer systems, some districts had underground drainage, which helped remove excess waste.

However, this system primarily served the wealthier areas of the city, which meant that most insula residents had no direct access to it.

The sheer number of people living in these cramped buildings, combined with the lack of adequate waste management, led to persistent sanitation problems.

As a result, diseases such as dysentery and intestinal infections spread quickly, which made survival difficult for those living in the most unsanitary conditions.

Motivated by these concerns, emperors such as Vespasian introduced public urinals, which were known as vespasianae, which generated revenue through a tax on urine collection for industrial purposes.

Because most insulae lacked private kitchens, tenants relied on purchasing prepared meals from street vendors and small food shops.

For example, many residents visited thermopolia, which were establishments that sold hot meals and simple dishes such as puls (a thick porridge made from grains), bread, and stews.

These shops were located throughout the city and often contained large ceramic storage jars set into counters.

These jars kept food warm and ready for customers. Wealthier tenants sometimes owned small hearths, which allowed them to prepare simple meals at home.

Because fresh ingredients such as vegetables, fish, and meat spoiled quickly without refrigeration, residents often relied on preserved foods, which meant that garum (a fermented fish sauce) became a staple for adding flavor to otherwise plain meals. 

Because open flames posed a constant threat, cooking inside insulae created significant dangers.

Those who cooked in their rooms used braziers, which were small portable stoves fueled by charcoal, but filled the air with smoke.

Roman authorities did try to introduce reforms and encouraged the use of safer building materials. However, these changes failed to eliminate the dangers entirely.