Drystone construction, as the name suggests, uses no mortar; stones are carefully fitted together so that their own weight and arrangement holds the structure. This particular hut is of subcircular plan, slightly elongated rather than truly round, and its dimensions are modest: roughly 1.9 metres by 3.4 metres internally, with walls surviving to only around 0.3 metres in height and approximately 0.9 metres thick. It is not a dramatic ruin. It is the kind of thing you could walk past without registering it at all.

What gives the structure some quiet interest is the entrance, set in the southwest wall and just 0.8 metres wide. One of the two upright portal stones that would originally have framed the doorway is still standing in its original position; the other has collapsed. These portal stones, flanking a narrow opening, are a common feature of early vernacular shelters across the Irish uplands, the sort of structures associated with seasonal agricultural activity, transhumance, or simply the needs of people working land far from a main settlement. The hut at Derrycarna appears as part of a group of such features in the area, sitting a short distance to the northwest of related remains, suggesting this corner of the Iveragh Peninsula once supported a small but organised pattern of use across the landscape.