The precious decoration, the opus sectile marble floors, the monumental architecture prove that this building belonged to the imperial noble quarters. Within the complex that we call the Imperial Residence, where the emperor lived, this building was the monumental entrance, a sort of atrium.
In this building all traditional elements of the Roman domus are reproduced, but on an imperial scale: the atrium with fountain TE1, the portico TE5 on which a large room TE20, opened: it was the tablinum, richly decorated.
Noteworthy are the dolphin-shaped capitals and the bases of the columns with very fine carvings that look like embroidery.
The Building with Three Exedras was interpreted by Kähler as a monumental triclinium based on the comparison with the Coenatio Jovis on the Palatine in Rome, which has a similar shape.
However, this hypothesis is unlikely because the triclinia could not be placed inside the exedras, because they were small gardens, and the beds could not be set under the sun.