The structure underwent conservation work by the Office of Public Works in 1936, evident in the replaced quoin stones on the angle towers, restructured parapets, and possible repairs to the main doorway on the eastern wall. The northwest tower, measuring 2.25 metres wide and projecting northwards by just 0.9 metres, houses the castle’s garderobes, whilst the slightly larger southeast tower contains the stairwell and projects 1.45 metres southward.

The main entrance, positioned just north of the southeast angle, showcases fine limestone craftsmanship with its two-centred arch and chamfered jambs. Beyond this doorway lies a north-south barrel vault featuring double-splayed openings in three walls, with a murder hole measuring 35 by 40 centimetres strategically placed in the roof. The first floor contains ogee-headed windows; two-light versions face north and south, complete with window seats, whilst a single light illuminates the western wall. Upper floors, once supported by corbels, feature progressively smaller windows, with single ogee-headed lights on the second floor and simple rectangular openings on the third.

The castle’s defensive features extend to its roofline, where all four corners boast towers rising above parapet level. The wall-walk, constructed from large flagstones with drainage holes through the parapets, connects these defensive positions, though access to the northeast tower is now blocked. Whilst the 1936 conservation work may have altered some original features, particularly the stepped battlements that appear to have existed on the north and east sides, the castle remains an impressive example of medieval fortification. Now designated as National Monument No. 298 under state ownership, Roodstown Castle continues to stand as a testament to Ireland’s turbulent medieval past.