12 Arthur Street, Hillsborough, County Down, BT26 6AP

12 Arthur Street is a mid-terrace single-storey stone house with attic dormer, built around 1830 as part of a substantial workers' housing scheme on the Downshire Estate. It is one of approximately 23 similar dwellings constructed during the mid-nineteenth century to accommodate estate workers and tenants.

The house is rectangular in plan form, with a pitched natural slate roof with clay ridge tiles and a centrally located dormer window. Cast-iron gutters with uPVC downpipes drain the roof, and a replacement brick chimneystack, shared with the adjoining building, carries two clay pots.

The walling consists of rubble masonry galletted with brick and sandstone surrounds to doors and windows. The building retains its original dressed stone archway with long-and-short surrounds, and a sandstone elliptical arched alleyway, shared with the adjacent dwelling, provides access to the rear. A robust half-circle sandstone label moulding runs over both the alleyway and the main windows, contributing to the building's modest, original character.

The front elevation faces west and is asymmetrically arranged. The ground-floor window is positioned to the left of the front door, with the shared arched alleyway to the right. The alleyway formerly gave access to the rear yard and now provides secondary access to a modern single-storey extension added to the rear. The left elevation abuts the adjoining dwelling (number 10), and the right elevation forms part of the passageway between number 20. Windows are modern replacements: timber casement, top and side hung, double glazed, painted white with applied lattice lead. They retain sandstone cills, though some show cement repairs. The front door is a replacement timber-sheeted example.

Despite substantial internal renovations, including the loss of original doors, windows, and many original materials, the building preserves its original modest style and proportions through its retained façade, making it an important component of the overall character of Arthur Street.

Historically, the Ordnance Survey maps of 1833 identify the earliest houses on Arthur Street as dating from the 1820s. By the town plan of circa 1834, six dwellings were recorded on the street, and the second edition Ordnance Survey map of 1858 shows the street as it appears today. Number 12 was constructed as part of the earlier phase of development, evidenced by its location and rubble masonry type. The Griffith's Valuation of 1862 records John Smyley as owner, with the house and yard valued at £2 10 shillings; the valuer noted that rents were 'moderate'. The single bedroom at first floor resulted in a valuation slightly lower than neighbouring houses. All houses on the street originally included a yard to the rear with a pit for household waste and a dry toilet; coal was typically stored in a hole under the stairs beside the living room, and water was supplied from a tap at the top of Arthur Street or a pump at the end of Wapping Street.

The building was listed in 1974. Alterations in the twentieth century include a bathroom and kitchen extension undertaken in 1975, which substantially contributed to the loss of original features.

The house forms part of a pair of matching terraces lining Arthur Street, which is accessed from Ballynahinch Street. The street is enclosed at its far end by a large rubble masonry wall, which formerly featured an arched opening, now infilled. The building lies within a conservation area.