The cities of the Roman world were filled with small shops that were rented from their owners by the shop keeper. Some shops were located on the ground floor of elite houses. Some on the ground floor of an insula. A number of such shops have been found at the well–preserved sites of Pompeii, Herculaneum, and Ostia (all in Italy).
The photo above is a view of the main entrance (just right of center in the light) to a wool processing/cleaning shop (a fullonica; see here for 5 additional images of this shop). Note the pool in the lower left, and the modern staircase that led up an upper floor of this shop. Jerome Murphy–O’Connor writes that typically merchants/craftsmen/etc. “. . . used the lower level for their shop and the upper level for living quarters” (see below for the important biblical discussion).
A fullonica was designed for the washing of dirty laundry and degreasing of fabrics. Based upon inscriptions it is believed that Stephanus was the owner of the fullery. He died during the eruption in 79 AD while trying to escape. The workers for Stephanus, almost all slaves, had to tread on fabrics and clothes for hours, placed in a liquid containing human and animal urine. The urine was collected in pots placed along the streets. The smell in a fullonica must have been “putrid” — but the shop was on a main street and houses (upper class) surrounded it! To view more images of the fullonica with commentary Click Here.
Jerome Murphy–O’Connor wrote p. 48:
The first churches may have occupied the upper-level living quarters of shops like this [his picture is that of a thermopolium—see my previous post]. Shopkeepers typically rented such . . . rooms [from landlords], which opened onto the sidewalk, and then built a wooden platform halfway up to divide the room into two levels [see the picture above!]. They used the lower level for their shop and the upper level for living quarters. . . . . Statements that Prisca and Aquila, at Ephesus and Rome, hosted “a church in their house” (1 Corinthians 16:19; Romans 16:5), or more literally, “the group [of believers] which meets in their home,” suggest that the early Christians met in the living room above Prisca and Aquila’s shop. Such a room could probably accommodate 10 to 20 persons. This may explain why Paul, at Corinth, preached in the synagogue and later in the house of Titius Justus, rather than in Prisca and Aquila’s home, where he lived (Acts 18:3–7), as these locations could accommodate larger crowds than a room above a shop.
Murphy-O’Connor, Jerome. “Prisca and Aquila — Traveling Tentmakers and Church Builders.” Bible Review 6 (December, 1992): 40–51, 62.