20 Castle Street, Newry, Co Down, BT34 2BY

20 Castle Street is a Grade B1 listed building forming the middle unit of a terrace of three three-storey townhouses with basement and attic, dating from the early Georgian period. It is located on the east side of Castle Street in Newry. The architectural composition of the terrace suggests that this building and number 22 were erected as a single unit.

The street-facing facade is three bays wide, constructed of random granite rubble with a moulded granite eaves course. The roof is gabled with natural slate covering, a coped verge, and a brick chimney positioned at the left. A cast iron skylight sits on the front pitch, with concealed gutters and a metal downpipe at the left side.

The ground floor contains a grained tongue-and-groove herringbone door at the centre, fitted with a plain transom above. Its exposed timber frame rests on painted granite blocks, with cement-rendered reveal and head. To the right is a pair of tongue-and-groove doors with louvred transoms, the right door incorporating a wicket, all set within a segmental headed coach arch trimmed with ashlar granite. The arch head is infilled with recessed rubble stone with strap pointing. To the left of the front door is a 2/2 sliding sash window with a rendered lintel extending the full width of its bay. Below ground level is a painted timber lintel, likely marking an infilled basement window. A short length of modern metal railing sits between the front door and coach arch, mounted on a chamfered granite plinth.

The upper floors each contain three 1/1 sliding sash windows aligned with the ground floor openings. All sash windows feature exposed boxes, rendered reveals, and painted granite cills. Those on the top floor are diminished in height with unequal pane sizes, suggesting the original configuration was 6/3 panes.

The left and right gables form party walls with the adjacent properties. The rear elevation follows the same construction as the front.

A three-storey gabled return projects from the right bay. Its ground floor rear elevation was not inspected, though a coach arch should be present at ground floor left. At first floor left is an exposed box 6/6 sliding sash window, and at second floor is a 6/3 window of similar type; the ownership of the top window is uncertain, as it may belong to number 20. Neither window has a cill, and the top window is diminished in height. The return has a gabled natural slate roof with a rendered chimney rising from the left cheek wall head. Half-round metal rainwater goods are present. The right cheek wall is random rubble, painted at ground floor and otherwise blank. The left cheek is random rubble at ground floor, not inspected. At first floor are three 6/6 sliding sashes, and at second floor are three diminished height 6/3 sashes, all aligned vertically. Windows on this elevation have shallow segmental brick heads or arches over them but lack cills. The rear gable is wet-dashed random rubble with a small casement window to the right.

A second return abuts this gable. It has a gabled natural slate roof, half-round metal rainwater goods, and wet-dashed walls. The right wall aligns with the left wall of the first return and is constructed of random rubble; the ground floor was not inspected. A 1/1 sliding sash window is present on both first and second floors, the upper one diminished in height, both with segmental brick heads but no cills. A further outbuilding abuts the gable of this return but is of no architectural interest.