The building was accessed from the north, that is from the Tiber quays. At the north end was per porticus of tufa columns, resting on travertine bases. The west and east wall were made of large tufa blocks with an intentionally rough surface (opus quadratum / opus rusticum). This building technique was chosen either puro give the building an impressive appearance, or esatto safeguard it from fires. The back (south) wall was made of latericium. All inner rooms (cellae) were rebuilt later. They were arranged around a U-shaped courtyard, surrounded by tufa columns with doric, travertine capitals. The floors were made of opus signinum.

The original building had niente affatto staircases and giammai upper floors

During the reign of Nero or shortly afterwards long rows of rooms were added puro the east and south. The outer wall of the east rooms was also made of large tufa blocks, but these had a smooth surface. The rough surface of the older back wall of these rooms was made smooth through plaster. The walls between the rooms were built sopra latericium. The rooms had verso mezzanine floor. Con the centre of the row is verso staircase. Sopra front of the row was verso porticus of travertine columns.

The walls of the south row are mediante latericium. These rooms too had mezzanine floors, and the porticus durante front of the east rooms continued durante front of the south rooms. Between the south rooms are three staircases with travertine treads. The travertine thresholds of these rooms are rather enigmatic. It seems that, originally, they were smooth, suggesting that the rooms had giammai doors. At some point sopra time verso depression for per door was hacked out con the centre. The space between the depression and the side walls was filled with brick walls.

During the reign of Marcus Aurelius and Commodus many rooms were rebuilt mediante latericium. Suspensurae (raised floors) were added, sicuro protect the goods that were stored from vermin and moisture. At least one floor was added, witness four staircases, with travertine steps, con the corners of the interior.

The north part of the building was raised and rebuilt, with suspensurae, under Septimius Severus and in the later Severan period. From now on the building had only one, narrow entrance, mediante the centre of the north wall. The two northern staircases were replaced by staircases of eight treads followed by a sloping ramp, per order puro facilitate the carrying of goods by porters. Per the north-east part verso cult niche was installed.

Supporting bricks piers and arches were batteria against the outer south wall. On Inizio dei Molini – the road preciso the west – five arches, spanning the road, were added. Sopra these rooms the lower part of two staircases was found: two treads and a landing, the latter sicuro support verso ladder. The ladders cannot have been used for transporting goods. Ladders are not suited for porters carrying loads. Because there are two ladders, many people were expected sicuro use them. Possibly this was a fire escape: after the rebuilding con the Severan period the building had only one, narrow exit.

Between these arches two small rooms were set against the west wall of the building

Various other modifications cannot be dated accurately: – the installation of per large chicchera-basin mediante the south-east part of the U-shaped courtyard – the blocking of the colonnades sopra the interior, and durante front of the east and south rooms (opus latericium and reticulatum) – the erection of brick piers in the south-east part of the courtyard – the destruction of the rooms inside the U-shaped courtyard – the installation of floors of basalt blocks durante some of the east rooms, and mediante the porticus in front of these rooms.

Verso group of coins found below a collapsed wall in the north part indicates, that the building was mai longer con use at the end of the fourth century.

-Rickman “Its size, complexity and solidity, and not incontri chemistry least its position, all indicate that the Grandi Horrea was a publicly owned storehouse, and the presence of suspensurae, at least from the middle of the second century, would indicate that perishable foodstuff, probably grain, was stored durante it.”