The House of the Stuccoed Capitals was a rich house, a domus, built in the second century BC. Today only the peristylium can be seen. Most of the building was replaced by the Seat of the Augustales (V,VII,1-2) to the north. Furthermore an apse from the late third century invaded the space of the peristylium.

The main entrance to the remaining part of the domus is from the south, through what was once the tablinum. In the peristylium was a porticus of tufa columns, except for the corners, where travertine columns are found. Most of the columns were later replaced by brick piers. The columns were decorated with stucco imitating fluting.

The peristylium could also be reached through a corridor to the west. Doors in the south wall of this corridor lead to some rooms in the south-west corner of the block: shops and backrooms. They were built in the Antonine or Severan period. The ambulacrum of the peristylium was decorated with a geometric black-and-white mosaic in the middle of the third century.

During further excavations in 2022 part of a stucco relief of Mithras was found in the building. The early reports say: "The interpretation of this stucco relief as a representation of the god Mithras in the act of sacrificing the bull was supported by the continuation of the excavation which, in addition to producing numerous other stucco fragments, led to the identification of the room in which it was found as a mithraeum".