What makes it quietly puzzling is precisely its anonymity: the walls, built from double-faced uncut stones laid in uneven courses, offer almost no architectural detail to read. A gap roughly two metres wide in the north wall may once have been a doorway, but beyond that, the structure keeps its character to itself. Its interior measures just over eleven metres east to west and just under six metres north to south, with walls surviving to no great height, and three further stub walls abutting the east face, suggesting at least one additional enclosed space was attached at some point.

When archaeologists excavated the site in 1982 and 1983, primarily to understand Knockmoy Abbey itself, they turned their attention to this building to settle the question of what it was and when it was built. The answer was unexpectedly late. The wall foundations bore no resemblance to medieval construction techniques, and the surviving stonework pointed to a post-seventeenth century date. The abutting walls and the secondary structure they helped form were later still, their foundation courses lying stratigraphically above the main building, meaning they came after it rather than alongside it. Stratigraphy, the reading of layered deposits to establish sequence, placed all of these walls above something older: a broad layer of dark soil and charcoal beneath the entire complex. Within that layer, outside the east wall of the main building, excavators found a single sherd of medieval pottery, a quiet signal that domestic buildings of the medieval period once stood in this same area, long before the post-medieval structure was raised on top of their remains.