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 to give the building an impressive appearance, or onesto safeguard it from fires. The back (south) wall was made of latericium. All inner rooms (cellae) were rebuilt later. They were arranged around verso U-shaped courtyard, surrounded by tufa columns with doric, travertine capitals. The floors were made of opus signinum.
The original building had per niente staircases and no upper floors
During the reign of Moro or shortly afterwards long rows of rooms were added onesto the east and south. The outer wall of the east rooms was also made of large tufa blocks, but these had per 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 durante latericium. The rooms had verso mezzanine floor. Con the centre of the row is verso staircase. Con front of the row was verso porticus of travertine columns.
The walls of the south row are in latericium. These rooms too had mezzanine floors, and the porticus in 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 no doors. At some point con time a depression for a door was hacked out mediante 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 in latericium. Suspensurae (raised floors) were added, preciso protect the goods that were stored from vermin and moisture. At least one floor was added, witness four staircases, with travertine steps, in the corners of the interior.
The north part of the building was raised and rebuilt, with suspensurae, under Septimius Severus and mediante the later Severan period. From now on the building had only one, narrow entrance, in the centre of the north wall. The two northern staircases were replaced by staircases of eight treads followed by per sloping ramp, durante order puro facilitate the carrying of goods by porters. Sopra the north-east part per cult niche was installed.
Supporting bricks piers and arches were attrezzi against the outer south wall. On Modo dei Molini – the road to the west – five arches, spanning the road, were added. Con these rooms the lower part of two staircases was found: two treads and verso landing, the latter preciso support a 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 puro use them. Possibly this was per fire escape: after the rebuilding con the Severan period the building had only one, narrow exit.
Between these arches two small rooms were attrezzi against the west wall of the building
Various other modifications cannot be dated accurately: – the installation of verso large chicchera-basin sopra the south-east part of the U-shaped courtyard – the blocking of the colonnades mediante the interior, and con front of the east and south rooms (opus latericium and reticulatum) – the erection of brick piers per the south-east part of the courtyard – the destruction of the rooms inside the U-shaped courtyard – the installation of floors of basalt blocks mediante some of the east rooms, and per the porticus mediante front of these rooms.
Per group of coins found below a collapsed wall per the north part indicates, that the building was giammai longer con use at the end of the fourth century.
-Rickman “Its size, complexity and solidity, and not least its position, all indicate that the Grandi Horrea was per 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 per it.”
