This paper presents the results of a magnetic survey on the Hellenistic and Roman site of Doura-Europos in Syria. The interpretation of the magnetic data is based on an original approach by considering the use of space in a domestic unit. This type of study has been developed for sociological research but is adapted to the information carried within geophysical data. After a brief presentation of the role of geophysical methods for the study of city planning, the most important components of the 'space syntax' will be presented and applied to two blocks of Doura-Europos, one that has been excavated in the twentieth century by the Yale University and another surveyed using the magnetic method.Key words: magnetic survey; city planning; domestic unit; space syntax; Doura-Europos; ancient Near East Si tu ne sais pas répondre à la question posée, demande toi si tu ne peux pas répondre a` une autre question qu'on a oublié de te poser (If you cannot answer a question, ask yourself whether you are able to answer another question they forgot to ask you) (Hesse, 1999)