50 Killyleagh Street, Crossgar, Co Down, BT30 9QD

50 Killyleagh Street is a substantial but relatively plain two-storey terrace house dating from approximately the 1870s, constructed as part of a larger block containing another smaller house. The building is situated on the north side of Killyleagh Street, close to the centre of Crossgar.

The south-facing front façade is asymmetrical in composition. To the right of centre is the main entrance, comprising a partly glazed door with fanlight and a plain surround with moulded keystone. To the left of the entrance is a sash window with vertical astragals and plain surround. Further to the left is a large elliptical arched carriage gateway with a similar surround to the main entrance, fitted with timber sheeted double doors and a wicket gate. To the right of the entrance are two sash windows matching those on the left, with five additional similar windows, unevenly spaced, arranged across the first floor. The front façade is finished in rough cast with in/out quoins.

The rear elevation contains a large modern single-storey extension with a gabled roof positioned at the left. The main rear façade has windows on the first floor: the far left window was obscured from view by the extension roof and appears to have a modern frame; to its right is a small window with coloured glass, which may originally have been larger before being shortened for the extension; further right are a larger window with a modern frame and another window with a sash frame. The rear façade is finished in recently applied dry dash. The gabled roof is covered with natural slate and has three yellow brick chimneys. The rainwater goods are mainly metal.

The building's original layout remains largely intact, retaining the original staircase, floor tiling, joinery detailing throughout, original glass in many windows, and some original fireplaces.

The 1859 valuation town plan of Crossgar indicates that this block was constructed sometime after that date. Based on its architectural style, it likely dates from approximately 1870 to 1880. The current owner believes it was originally used as the local police station; however, historical map evidence suggests that the police station or 'barrack' remained sited in Downpatrick Street until at least the latter half of the twentieth century. A rear extension was added circa 1980.