Walk around to the rear, however, and the building reveals a different storey altogether. A basement, invisible from the entrance front, becomes apparent only from behind, where a gabled three-storey projection rises above more recent additions. It is the kind of architectural secret that a casual passer-by would never suspect.

According to local tradition, the house was built in the eighteenth century as a dower house for Castlemary House, a nearby estate in east Cork. A dower house was a secondary residence provided for a widow of the main estate, allowing her to remain on the family's lands after her husband's death without occupying the principal family seat. The connection to Castlemary gives the Ballynacorra house a particular social function; it was built not as a grand statement in its own right, but as a practical and dignified provision within the wider domestic economy of a landed family. The building's limestone detailing, including a band course running between the ground and first floors, cut stone chimney stacks on the gables, and the Doric order applied to the front door surround, reflects the restrained classicism that was fashionable in Irish provincial architecture during that period. The low two-storey hipped wing on the north side adds further complexity to what might initially appear a straightforward composition.