The jambstones, the shaped uprights that frame a doorway, were removed in 1943 or 1944, taking with them the most finished stonework in the building. Everything else here was built without cut stone, which gives the ruin at Killincarrig an unusually plain, almost severe character for a house of its class and period.

The structure dates to the early seventeenth century and was most probably built for Henry Walsh. The main block measures roughly fourteen metres long by seven and a half metres wide, gabled, and originally two storeys tall with an attic above. A stair turret projects from the western wall, directly opposite the eastern entrance, a layout that kept circulation efficient in a relatively compact house. Attached to the northeast is a kitchen block of similar height and construction, with internal dimensions of just under seven metres by five. What survives most visibly today are the chimney stacks on the northern and western walls of the main block, both described as substantially intact, solid evidence of a building that was once genuinely inhabited rather than merely symbolic. The armorial recess above the former entrance hints that the Walshs were keen to signal status, even if they chose rubble construction over dressed stonework throughout the rest of the building.