The first building phase appears to go back to Hellenistic times, (An example of Hellenistic masonry can still be seen on the exterior of the north side).
The life of the building, with various repairs and remodellings, continued until at least the 3 rd c. AD.
The rooms are organised around three inner courtyards, two of which have peristyles with Rhodian-type colonnades.
Opposite the entrance is a statue-base with the inscription:
"ΑΠΑΛΕΞΙΚΑΚΟΣ" (He who wards off evil), The windows in the wall behind this statue-base look on to the first courtyard (1), where there is a water cistern and a mosaic floor with a depiction of a panther tearing apart a dear. Various rooms open on to this courtyard:
- The one at the west (2) has a marble-paved floor at the centre of which was discovered a mosaic “device” of the Hellenistic period, depicting life under the sea.
- The room (3) to the south of the west room has a well-preserved wail-painting depicting a male figure.
To the south of the first courtyard, is the andron (4), which opens on to the large south, peristyle courtyard which has a small water cistern at the centre, The courtyard (5) is surrounded by rooms, some of which have traces of marble revetment on the walls; the floors of some had mosaics (with geometric motifs, depictio of tiger, panther etc.), while others were paved with marble. The area at the north-west corner of the courtyard (6), near the staircase leading to the upper store was devoted to ancillary rooms.
The andron communicated by way of a door in its west wall with a large hall (the triclinium) (7), which had a marble-paved floor and marble-revelled walls. On the north side of this is the third of the courtyards (8), with a water cistern and a mosaic floor depicting Nereid riding on sea-horse. The scene is flanked by panthers and dolphins.
All the mosaics found in the Casa Romana date from the 3 rd c. AD.
A number of statues dating from the late Hellenistic period were also found in the building and these, together with the mosaic with the scene of life under the sea, which adorned the north courtyard (8) of the house, are on display in the Kos Museum.
To the east of the Roman House is the Baths complex; a short distance away to the north-east are to be found the Hellenistic Altar and Temple of Dionysos and to the west lie the Roman Odeion of the 3
rd c. AC and the West archaeological site (with the Houses of Europa and Silenos, the Baths and the mosaic of the Judgement of Paris),