Seskin House presents a composed, if irregular, facade to the world, but its floor plan tells a more complicated story. The building's unusual footprint, with projecting bays on half-octagonal plans, recessed central sections, and a substantial service range extending to the north, does not sit easily with the idea of a single building campaign. It is the kind of house that suggests accumulation rather than intention.

The documentary trail reaches back to 1675, when a property at Seskin was mentioned in the will of one John Meagh, a reference preserved in the Carrigan Manuscripts and recorded in the Irish Genealogist. The house that stands today dates largely from around 1825 in outward appearance, but architectural analysis points to an earlier core, possibly from around 1725, absorbed into the later structure. The half-octagonal bays and the irregular, evolving plan are consistent with a building that was extended and remodelled rather than conceived whole. Whether an eighteenth-century range was substantially redeveloped in the early nineteenth century, or whether the composition grew more gradually over time, is not entirely clear. The fabric of the walls may hold the answer, though it does not readily give it up.