20 Church Street, Ballynahinch, Co. Down, BT24 8AF

20 Church Street is a large two-storey terraced house on the slope of Church Street, to the south of Ballynahinch town centre, County Down. It originated as three separate properties built around 1840 and retains a late Georgian and early Victorian appearance despite having been fully amalgamated into a single dwelling around 1920–25.

The front façade faces west and is finished in lined render, painted. To the left is the principal entrance doorway, set within a large elliptical arch recess. The door itself is a boarded four-panel timber example, flanked by Doric columns that support an entablature, with a spider-web elliptical fanlight above. To the left of the doorway is a sash window with simulated margin panes — the glazing bars are stuck to the inside of a plain single pane rather than being true glazing bars — set within a moulded surround with keystone, an arrangement probably added around 1920–25. To the right of the doorway are two further windows of the same type, followed by an elliptical carriage arch with timber-sheeted double doors and a simple surround with keystone, then two more windows of the same pattern but shorter in height. At first-floor level there are seven unevenly spaced windows, matching those at ground floor to the far right but without the simulated margin panes. Four rendered chimney stacks rise from the gabled roof of the main house, which is covered in natural slate. Three Velux windows are set into the rear slope.

The rear elevation is considerably more complex, reflecting the building's layered history of amalgamation and extension. To the left of the carriage arch is a two-storey gabled return (Return A). Against the south face of this return, and joined to the rear of the main building, is a single-storey flat-roofed extension; its east face has a single window with a modern frame. The first floor of the south face of Return A has two small sash windows, and the corresponding first-floor section of the main rear façade to the left of the return has a tall window with a late Victorian fixed-light frame with arched tracery, which is reported to have originally belonged to the nearby St Patrick's Church. The gable of Return A has a timber-sheeted door to the left at ground-floor level, two small windows to the right at ground floor, and a slightly larger window at first-floor level, all with modern frames matching that of the flat-roofed extension. The north face of Return A is blank.

To the right — that is, to the north — of the carriage arch is a second two-storey return (Return B). The south face of this return has two ground-floor sash windows with Georgian panes (six over six) and a similar window to the right at first-floor level. The gable of Return B has a similar six-over-six sash window at first-floor right and a twelve-pane window with Georgian-style panes at ground-floor right. At ground-floor left, a single-storey gabled section extends eastwards; its north face has two small nine-pane windows and its south face is blank. The roof of this section continues further east, where it abuts a large two-storey outbuilding. The north face of Return B is blank, but at ground-floor level it is abutted by a large single-storey L-shaped extension with a hipped roof, added by the current owner since 1977. The short east face of this extension, close to Return B, has a timber-sheeted doorway with a multi-pane sidelight. The main south face has two nine-pane windows with Georgian-style panes. The short east end face has a pair of French-style doors with multi-pane sidelights. The long north face appears to be blank. This L-shaped extension has one Velux window.

Above the carriage arch, set into the rear façade of the main house, is a first-floor sash window with Georgian panes (six over six). To the right of Return B at first-floor level are two semicircular-headed windows: the left one is broader and has margin panes, while the right one is narrower and taller with Georgian-style panes. To the more southerly, north-facing wall of the carriage arch there is a large six-pane window with a timber-sheeted panel beneath it.

The finishes to the rear vary. Most sections are finished in unpainted roughcast, but all facades from the south face of Return B southwards are finished in fine roughcast and painted. The roofs of the returns and extensions are covered in natural slate, with the exception of the flat-roofed extension to the far south. Rainwater goods are a mixture of cast iron and aluminium.

The large two-storey outbuilding to the rear is rendered and painted, with a hipped slated roof, and has a variety of windows including some set into gabled half-dormers. To the east, the outbuilding drops to single storey because of a dramatic rise in ground level.

The northern end of the main roofline sits slightly lower than the rest, marking the extent of what was once a separate and smaller property. The building's history is well documented. Much of Church Street was undeveloped when the first Ordnance Survey map of the area was made in 1833–34, though a house is recorded on or near this site, identified in contemporary valuation records as a low two-storey dwelling belonging to a Michael Nugent. The present terrace appears to have been built around 1840, with the future No. 20 comprising two houses — one on each side of the carriage arch — and a smaller property at the very north. These may have been built by a local surgeon named White, who is recorded as an early occupant of the house north of the carriage arch, with the smaller northern property serving as his dispensary. Around 1855, White sold the lease of the whole group to another doctor, James Dickson, who continued to use the dispensary. The Dickson family and their relatives by the name of Earl remained in possession of both houses and the dispensary until 1902, when the lease was sold to a John Coulter. Coulter is believed to have amalgamated the three properties into a single house around 1920–25. The current owner acquired the property in 1977 and subsequently added the L-shaped rear extension.