Visible from outside, the remains of a small vaulted chamber survive in partial form, its arch projecting eastward and hinting at a building that once stood independently on this plot before later construction absorbed it.

What survives is the first course of voussoirs, the wedge-shaped stones that form an arch, projecting from the wall and indicating that the original vault ran east to west. The walling sitting within the arch appears to be the internal face of the western end of this earlier structure, and some of the surrounding masonry is contemporary with it, meaning these stones were laid together as part of the same original build. The southern wall of the outbuilding was constructed directly against the existing eastern wall, a sequence of construction that reveals how the later builder simply worked around what was already there. The vaulted chamber itself was modest, measuring roughly 1.78 metres high and 2.87 metres wide, and was likely used for storage. It is a scale that suggests something functional rather than ceremonial, a cool, dark space of the kind that served domestic or agricultural purposes throughout medieval Irish towns.

Fethard is one of the better-preserved medieval towns in Ireland, and its streetscape and backland areas contain layer upon layer of built history. This particular fragment, half-swallowed by a later outbuilding, is the kind of detail that rewards a slow walk through the town's quieter laneways and rear plots, where the less celebrated remnants of its past tend to survive.