One portion is thatched, the other slated, and the reason for that disparity is not architectural fashion but arson: after a thatch renovation was set alight, the Conservation Office permitted the damaged section to be reroofed in slate rather than restored again in kind. Look closely at the junction between the thatched bay and the round entrance hall and you can see where plastic underlining has begun to show through the patching.

The building itself is a multi-period structure whose western end is considered the earliest portion, probably dating to the sixteenth or seventeenth century. It has clay walls and a steep gable, measuring roughly eleven metres in length and five metres in width, with wall thickness of around 0.6 metres. That western section, comprising a single chamber and a corridor, was eventually absorbed into a more formalised cottage built around 1785. The house is almost certainly the same structure marked on the Down Survey map of 1650 and identified in the Civil Survey of 1654 to 1656 as the only farm house in the townland then recorded as Tankerstowne. In 1702 the property was sold to a John Rottorn of Dublin, as documented in a National Library of Ireland manuscript. The Down Survey, it is worth noting, was a mid-seventeenth-century mapping project commissioned by the Cromwellian administration to catalogue Irish land ownership prior to large-scale confiscations.

The building is a Record of Protected Structure and sits within a landscaped entranceway surrounded by trees and enclosed by a wooden fence. Its current life as the Balbriggan Community Crèche and Playschool means access to the interior is not generally available to casual visitors, but the exterior rewards a close look. Three large bays sit to the right of the distinctive round entrance hall, with four chimneys above; to the left, three smaller windows and two chimneys mark the slated section. An east-west wing intersects the main range, adding to the building's irregular, accumulated character. The patched thatch near the entrance hall, with its visible underlining, is an unintended record of the structure's recent difficulties as much as its older ones.