That much is known. What remains uncertain is almost everything else: when it was built, by whom, and in what condition it survives. It carries the designation of a recorded monument, meaning someone, at some point, judged it significant enough to document, yet the structure sits without a date, without a period attribution, classified only as a house of indeterminate age.

Coollisduff is a small rural townland in Mayo, a county that contains an unusually dense concentration of archaeological and vernacular remains, from prehistoric field systems preserved beneath bogland to post-medieval settlement clusters abandoned during the clearances and the Famine years of the 1840s. A house recorded without a date could belong to almost any of these periods. Vernacular rural houses in the west of Ireland range from late medieval tower-house dependencies to nineteenth-century single-room dwellings built of dry stone or mortared rubble, and distinguishing between them on the ground, without excavation or documentary research, can be genuinely difficult. The absence of a date here is not necessarily an oversight; it may simply reflect the honest limits of what surface survey alone can determine.