The building was accessed from the north, that is from the Tiber quays. At the north end was verso 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 onesto 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 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 mai upper floors
During the reign of Gelso 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 verso 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 con latericium. The rooms had verso mezzanine floor. Sopra the centre of the row is per staircase. Con front of the row was verso porticus of travertine columns.
The walls of the south row are durante latericium. These rooms too had mezzanine floors, and the porticus mediante front of the east rooms continued con 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 mai doors. At some point durante time per depression for verso door was hacked out per 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, onesto protect the goods that were stored from vermin and moisture. At least one floor was added, witness four staircases, with travertine steps, per the corners of the interior.
The north part of the building was raised and rebuilt, with suspensurae, under Septimius Severus and con the later Severan period. From now on the building had only one, narrow entrance, durante the centre of the north wall. The two northern staircases were replaced by staircases of eight treads followed by verso sloping ramp, per order to facilitate the carrying of goods by porters. Sopra the north-east part per cult niche was installed.
Supporting bricks piers and arches were serie against the outer south wall. On Strada dei Molini – the road puro the west – five arches, spanning the road, were added. Sopra these rooms the lower part of two staircases was found: two treads and verso landing, the latter onesto 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 verso fire escape: after the rebuilding sopra prezzi seniorpeoplemeet 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 verso large vaso-basin sopra 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 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 sopra some of the east rooms, and mediante the porticus per front of these rooms.
Verso group of coins found below a collapsed wall in 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 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 per it.”