The Victorian-era facing, added by the Sullivan family in the nineteenth century, was laid onto what researchers have described as a fifteenth or sixteenth century building beneath, and that layering is precisely what makes the place odd and worth attention. The medieval bones show through: an arch of the appropriate period survives inside one wall, and at some point during work on the building an armorial plaque was found embedded there, bearing part of an Archer coat of arms alongside an incised carving of a man in sixteenth-century dress.

The milling history at Lacken stretches back at least to 1307, when a medieval source records a mill at this location. By 1425 the Earl of Ormond had granted two mills to a Walter Sherlock, and the surrounding land was known for some time afterwards as Sherlock's land. A mid-seventeenth-century parish map produced during the Down Survey, which was the Cromwellian government's effort to document landholding across Ireland in the 1650s, marks a watermill here and notes that a mill in the area was in repair, listed as Corporation Land in 1640. The Civil Survey of the same period is more specific: it describes "Lackings Mills being 3 in number under one roof, whereof there are 2 Corne Mills and 1 Tuck Mill," with stone walls and a thatched roof, and names Thomas Lein as the tenant at the time the town was taken. A tuck mill, also called a fulling mill, was used to pound and clean woven cloth rather than grind grain, so the complex was serving both agricultural and textile needs simultaneously. Adjacent to the surviving building, a silted-up mill stream can still be traced alongside the channel that once drove the twin mill wheels. The Archer coat of arms, incidentally, is not unique to this site; another appears at the former Archersgrove mills roughly a kilometre and a half to the south-east, suggesting the family had a presence across several industrial sites along this stretch of the Nore. The mills at Lacken fell silent in 1946 and have remained so.