That modest description comes from the Civil Survey of 1654 to 1656, a comprehensive Cromwellian-era land assessment that documented property ownership across Ireland in considerable detail. It places a thatched dwelling at Lismortagh as early as 1640, at a time when the land belonged to one Phillip Parcivall of Dublin, identified in the survey as an English Protestant, a designation that carried real legal and political weight in the fractured landscape of pre-Cromwellian Ireland.

The house that stands today presents a very different face. It is a five-bay, two-storey structure over a half-basement, with a three-storey central return projecting to the rear, a form typical of the confident, well-proportioned domestic architecture that spread across the Irish countryside during the mid-eighteenth century. Five-bay symmetry of this kind was a marker of genteel aspiration, the facades arranged around a central door to give an impression of order and solidity. Yet the building may be more layered than it appears. Historians and architectural surveyors have noted that despite its mid-eighteenth century appearance, the house could incorporate fabric from an earlier structure, meaning the walls themselves might carry material memory of that long-vanished thatched dwelling Phillip Parcivall once owned, before the upheavals of the 1640s changed ownership patterns across the country so dramatically.