A traditional definition of an insula is a multistory, habitable dwelling for multifamily use; usually synonymous with the English word ‘apartment.’ Iulius Paulus states "insulae properly defined are entities not joined by party walls with neighboring entities, and are surrounded by a public or private pathway."[1] The first floors were usually tabernae, or shops, and all the inhabitable spaces were on the upper floors with exterior staircases leading to the different levels. The individual apartments are called coenacula and “the coenaculum again is divided into several rooms of which we can name three: the exedra, the cubiculum, and the medianum.”[2] Therefore the insula can be defined as an apartment house, the coenaculum as a private apartment unit, a cubiculum is a bedroom, the exedra is a living room area, but the word medianum is vague. According to Hermansen, medianum, or the middle room, was a shared space for all the inhabitants of an insula rather than the private space of an inquilinus (tenant), and may have been a communal cooking and dining area.[3]
The height is debatable, they seem to be anywhere between three floors to the highest recorded insula, the Insula Felicles, at eight stories tall.[4] The Insula Felicles was most likely the tallest insula in existence since it is the only insula to be mentioned by name in the Regionaries, and to be listed among other noteworthy monuments implies that it was extraordinary. Building to these heights was not without its problems, as often the apartments would collapse from the weight. The unsteady nature of inuslae caused Augustus to limit the height to 70 RF (Roman feet) in order to decrease the chance of collapse (Strabo 5.3.7), but a height of 70 RF “would have probably been at least seven stories high, and such towering insulae seem to have been common.”[5] Nero then reinforced the limit after the fire of 64 CE, and Trajan lowered the height to 60 RF during his reign (Tac. Ann. 15.43; Sext. Aur. Vict. Epit. 13.13). However, it is unknown if builders actually stayed within these limits.
During the Republic and early Empire, construction would have been of brick, concrete, or stone with the upper levels constructed of wood and mud or tiles to lessen the weight and expand the height.[6] However, the mud and wood construction was flammable and prone to stress fractures, and the danger of fire and collapse caused Nero to ban the use of wood for construction, mandating that fire-resistant stone be used, and discouraging shared walls between buildings. To further minimize the risk of fire, Nero also widened streets and "tenement congestion was to be reduced by the provision of both internal courtyards and porticoes on the ground floor facing the street, which could also serve as protection against falling debris in the event of a fire."[7] Shallow balconies protruded from the front of the insulae, yet “were clearly not intended for regular family use and were sometimes completely impracticable,” they were most likely ornamental or utilized to catch objects falling out of the windows.[8]
[1] Paulus in Festus, De Significatu Verborum, 111M, as quoted by Storey, 56.
[2] G. Hermansen, “The Population of Imperial Rome: The Regionaries,” Historia, Vol. 27 No. 1 (1978), 131.
[3] Hermansen, Ostia: Aspects of Roman City Life, Alberta: University of Alberta Press (1982), 21-22.
[4] Tertullian (Adversus Velentinianos, 7.1-3) mocks the height of the Insula Felicles stating, “you would think the many floors of heaven constituted a kind of insula Felicles. I do not know where you would find the god of the Valentinian heretics. They dwell at the highest part of the roof on the tiles.” Glenn Storey (“The Meaning of Insula,” 77) interprets this as meaning it to be eight stories tall since Valentinus believed in eight deities.
[5] Gregory Aldrete, Floods of the Tiber in Ancient Rome, Baltimore: John Hopkins University Press (2006), 106.
[6] Vitruvius, De Architectura, 2.8.17-2.8.20. Vitruvius tells us that walls were limited to a thickness of one and a half feet in Rome due to lack of space. This thickness could not support more than one floor, so the upper stories were made of lighter materials such as wooden frames with mud walls. He states that wattled walls lead to calamity since they easily catch fire and are prone to cracks and collapse. Conversely, walls constructed of tile are lasting.
[7] Miriam T. Griffin, Nero: The End of a Dynasty, New York: Routledge (1984), 130.
[8] Alexander McKay, Houses, Villas, and Palaces in the Roman World, Cornell University Press, 1975, 91.
The height is debatable, they seem to be anywhere between three floors to the highest recorded insula, the Insula Felicles, at eight stories tall.[4] The Insula Felicles was most likely the tallest insula in existence since it is the only insula to be mentioned by name in the Regionaries, and to be listed among other noteworthy monuments implies that it was extraordinary. Building to these heights was not without its problems, as often the apartments would collapse from the weight. The unsteady nature of inuslae caused Augustus to limit the height to 70 RF (Roman feet) in order to decrease the chance of collapse (Strabo 5.3.7), but a height of 70 RF “would have probably been at least seven stories high, and such towering insulae seem to have been common.”[5] Nero then reinforced the limit after the fire of 64 CE, and Trajan lowered the height to 60 RF during his reign (Tac. Ann. 15.43; Sext. Aur. Vict. Epit. 13.13). However, it is unknown if builders actually stayed within these limits.
During the Republic and early Empire, construction would have been of brick, concrete, or stone with the upper levels constructed of wood and mud or tiles to lessen the weight and expand the height.[6] However, the mud and wood construction was flammable and prone to stress fractures, and the danger of fire and collapse caused Nero to ban the use of wood for construction, mandating that fire-resistant stone be used, and discouraging shared walls between buildings. To further minimize the risk of fire, Nero also widened streets and "tenement congestion was to be reduced by the provision of both internal courtyards and porticoes on the ground floor facing the street, which could also serve as protection against falling debris in the event of a fire."[7] Shallow balconies protruded from the front of the insulae, yet “were clearly not intended for regular family use and were sometimes completely impracticable,” they were most likely ornamental or utilized to catch objects falling out of the windows.[8]
[1] Paulus in Festus, De Significatu Verborum, 111M, as quoted by Storey, 56.
[2] G. Hermansen, “The Population of Imperial Rome: The Regionaries,” Historia, Vol. 27 No. 1 (1978), 131.
[3] Hermansen, Ostia: Aspects of Roman City Life, Alberta: University of Alberta Press (1982), 21-22.
[4] Tertullian (Adversus Velentinianos, 7.1-3) mocks the height of the Insula Felicles stating, “you would think the many floors of heaven constituted a kind of insula Felicles. I do not know where you would find the god of the Valentinian heretics. They dwell at the highest part of the roof on the tiles.” Glenn Storey (“The Meaning of Insula,” 77) interprets this as meaning it to be eight stories tall since Valentinus believed in eight deities.
[5] Gregory Aldrete, Floods of the Tiber in Ancient Rome, Baltimore: John Hopkins University Press (2006), 106.
[6] Vitruvius, De Architectura, 2.8.17-2.8.20. Vitruvius tells us that walls were limited to a thickness of one and a half feet in Rome due to lack of space. This thickness could not support more than one floor, so the upper stories were made of lighter materials such as wooden frames with mud walls. He states that wattled walls lead to calamity since they easily catch fire and are prone to cracks and collapse. Conversely, walls constructed of tile are lasting.
[7] Miriam T. Griffin, Nero: The End of a Dynasty, New York: Routledge (1984), 130.
[8] Alexander McKay, Houses, Villas, and Palaces in the Roman World, Cornell University Press, 1975, 91.