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

15 Arthur Street, Hillsborough, is a Victorian mid-terrace single-storey with attic workers' cottage built around 1850 to house workers and tenants of the Downshire Estate. It forms part of a historically significant terrace that developed in stages throughout the first half of the 19th century, with the earliest houses appearing on the 1833 Ordnance Survey map dating from the 1820s, and the remainder of the street completed by the second edition OS map of 1858.

The building is rectangular in plan with a single-storey modern extension to the rear. Its front elevation faces east and is asymmetrically arranged, with a ground floor window positioned to the left of the front door. The most prominent feature is a sandstone elliptical arched alleyway with long-and-short surrounds, painted black, which is shared with the adjoining dwelling. This alleyway originally provided access to the rear yard and now serves as secondary access to the modern extension.

The exterior displays coursed rubble masonry typical of the later phase of Arthur Street construction, characterised by more regularly cut stone laid to courses, contrasting with the earlier random rubble masonry and granite mouldings found in the first phase of development. The walling retains painted smooth render surrounds to doors and windows. The building has a pitched natural slate roof with clay ridge tiles, crowned by a replacement brick chimneystack shared with the adjoining building and topped with two clay pots. A large modern flat roof dormer has been added, and uPVC rainwater goods have been installed.

The front elevation retains its original dressed stone archway and stone hood mouldings, preserving the modest style and proportions characteristic of the period. Windows are modern top-hung, single-glazed timber casements painted white, with lattice lead applied to the face and concrete cills painted white. Robust half-circle sandstone label moulding, painted black, adorns each window opening, matching the label-mould over the alleyway. The modern front door is timber, painted black.

The left elevation abuts the adjoining dwelling at number 17, while the right elevation forms part of the passageway between number 13. The rear elevation is now largely obscured by the single-storey modern extension.

According to Griffith's Valuation of 1862, the house was then owned by John Smith and valued at £2 15s including the yard. The valuer noted that rents were "moderate" and recorded that this property claimed ownership of the passageway and enjoyed an additional bedroom positioned above it, resulting in a valuation slightly higher than neighbouring properties. Originally, all houses on Arthur Street were provided with rear yards containing a pit for household waste and a dry toilet. Coal was typically stored in a hole under the stairs adjacent to the living room, and water was supplied either from a tap at the top of Arthur Street or from a pump at the end of Wapping Street.

The building was listed in 1974. It has undergone various 20th-century alterations and additions, including replacement of dormers in 1990 and installation of skylights in 1999. Despite these changes and the loss of original dormer windows and replacement of many original materials internally and externally during recent renovations, the building retains architectural and historical significance as an important part of the overall character of Arthur Street.

The street itself is a notable townscape feature, forming part of a pair of matching terraces. It is accessed by a single entrance from Ballynahinch Street, with the other end closed by a large rubble masonry wall, into which an arched opening has been infilled. The building is located within a conservation area and contributes to the group value of Arthur Street as a whole.