SU 8367 is a concrete wall that served to divide Room I-17 from I-20 and I-22 to the north, constructed as part of the original phase of the building. The 'curve' to the north toward the western end described above appears to relate to a N-S wall that was bound to 8367 and extended north from it a very short distance, ending at a threshold linking Room I-20 with I-22 to the west. Indeed, while this northward extension is only very partially preserved, at the very bottom there is a brick that appears to represent all that remains of the northern facing, separating the wall from a concrete/signinum threshold which is fragmentary and only barely visible (pending further excavation of I-22 next season; see photo from north). Significantly, since a cut provides access to the lower courses of this wall, we can see that there are at least three courses of brick/tile below the level of the preserved floors. We see similar brick/tile courses in only a few other walls (at the same depth), and (higher up, ca. 2-3 m above the floors) in collapsed walls within collapse 8318. Thus some might refer to these walls as opus vittatum rather than (as currently labeled, prior to seeing these) petit appareil.

The wall curves slightly northward at its western side, this northern side is not completely excavated but as of 2018, it appears to be truncated by later activity. No further excavation evidence supports that this wall is related to a substructure, rather, it is now interpreted as part of the southern limit of I-20.