Tell Beydar is one of the most important excavated sites in Upper Mesopotamia, with a main occupation level of the Early Dynastic Period and a reoccupation in Hellenistic times. The Hellenistic levels are indeed situated directly on the top of those of the 3rd millennium and most of the architectural remains belong to a single residential building with two main phases. According to the chronology proposed on the basis of the material culture data, this palace was built around the middle of the 2nd century BC and, after a period of abandonment, it was reoccupied until the middle of the 1st century BC. In the present report, the building techniques and the architectural phases (I-III) are described stressing the importance of Phase II, the main phase of use of the building: in this phase, the interior was coherently divided into storage, cooking and service rooms, in order to perform domestic activities, in particular textile.