The walls preserve the evidence of at least three distinct phases of construction, each one partially cancelling out what came before. A round-headed window in the east gable was knocked through and then blocked when a chancel was added. A later doorway was inserted directly into the chancel arch, infilling the arch itself. A carved stone mullion from an ogee window, presumably dislodged at some point after the building fell out of use, ended up repurposed as a grave marker in the churchyard to the south. The structure reads less like a finished design than like a series of pragmatic decisions accumulated over several centuries.

The church stands on a slight rise within what was once a wider medieval settlement at Moycarky, and it appears in the ecclesiastical taxation of the Diocese of Cashel as early as 1302. The nave, the older portion, is a plain rectangular space built of coursed limestone with large quoinstones, those cornerstone blocks that give medieval Irish masonry its characteristic alternating rhythm of large and small. The west wall retains the ghost of a tall round-headed embrasure that was later replaced by an ogee-headed window, the ogee being a flowing S-curved arch form associated with later medieval craftsmanship. Four corbels, projecting stones designed to carry a timber beam, run along the west wall at a consistent height, suggesting the nave once had an internal wooden gallery or loft. The chancel was added in the fifteenth century, requiring the demolition of part of the original east gable and the insertion of a new chancel arch with chamfered edges and diagonal tooling. Then, somewhere in the sixteenth or seventeenth century, a doorway was punched through that arch and the remaining opening filled in. The east gable of the chancel still carries a bellcote, a small stone turret designed to hold a single bell, with cut stone quoins framing a flat-headed opening at the top.

The two-light ogee window in the chancel's east gable is the most elaborately finished element remaining, with decorated cusps and a hood-moulding visible from outside. Its central mullion is gone from the window itself, but, as noted, a fragment of it survives nearby in the graveyard south of the church, doing quiet, unintended duty as a headstone.