What survives at the site, who built it, and when, are questions the available record has not yet answered in any accessible form.

The name Ballynakill derives from the Irish Baile na Coille, meaning townland of the wood, a placename pattern common across the west of Ireland and one that often signals long settlement in a landscape that has since been cleared and transformed. Derrycallan, the broader townland, similarly carries an Irish name suggestive of early habitation. Country houses in this part of Galway were frequently built by Anglo-Irish landowning families during the eighteenth and nineteenth centuries, sometimes on or near the footprint of earlier structures, and the formal designation of Ballynakill House as a monument suggests the site has archaeological as well as architectural interest. Beyond that, the specifics remain tantalisingly unconfirmed.