Among its quieter details are the foundations of a long, rectangular building, internally subdivided, that dates to the eighteenth or nineteenth century. Just twenty-two metres south of a related house site on the island, these two structures together suggest that Church Island was not simply a place of early medieval piety but also, considerably later, a place where ordinary domestic life continued or was briefly resumed.

The Iveragh Peninsula has one of the densest concentrations of archaeological remains in Ireland, ranging from prehistoric field systems to early Christian enclosures. Church Island itself takes its name from the monastic presence established there in the early medieval period, and the survival of later building foundations alongside those older traces points to a longer, more layered pattern of habitation. The foundations recorded here, along with the neighbouring house site, appear to belong to a period when small island communities along the Kerry coast were still maintaining a foothold, however modest, on land that would eventually be abandoned entirely. The subdivision of the interior suggests a building organised for domestic use rather than storage or shelter alone, perhaps a dwelling of two rooms, which was a common arrangement in rural Kerry housing of that era.