The Georgian façade facing the River Nore presents a composed, mid-eighteenth-century face to the world, but behind it lie the walls of a substantially older structure, and beneath it, arched basement chambers that may predate even that.

The building at Nos. 88 and 89 John Street began as a late sixteenth or early seventeenth-century stone mansion house, sited on the east bank of the Nore beside John's Bridge. In the mid-eighteenth century it was remodelled as a dower house, a residence provided for a widow of rank, in this case for the widow of the second Duke of Ormonde, who undertook the work alongside her son the Earl of Arran. That remodelling gave the house its present Georgian character, complete with stucco ceilings and fireplaces that contemporaries described as some of the finest rooms in Kilkenny. The social life that followed matched the rooms: Sir Walter Scott and Maria Edgeworth were among those who visited during the celebrated era of the Kilkenny Theatre. Then, during the Civil War of 1922 to 1923, the house was attacked, and the marks of that episode remain on the exterior wall. Archaeological investigations have since confirmed that the older mansion survives in considerable quantity: original hood-moulded window surrounds, a term for the projecting stone frames that channelled rainwater away from window openings, are still visible in the rear gable, and late sixteenth or early seventeenth-century masonry runs through the north, south, and east walls to second-floor level. The foundations of the original west wall have also been located below ground. The arched basement beneath No. 88 may be older still; the archaeologist Alan Hayden has proposed it could be associated with a structure at the east end of the medieval St John's Bridge, which crossed the Nore at a point further downstream than the present bridge.