18-22 Hill Street, Belfast, Co Antrim, BT1 2LA

Nos 18–22 Hill Street is an attached two-storey former warehouse built around 1850, with the current façade representing a complete rebuild carried out in 1871. The building is rectangular on plan, faces east onto Hill Street, and has been extended to the south and west. It now contains a performance space and bar at ground floor level (Nos 20 and 22) and office space at first floor (No 18), and has been home since 2006 to the Black Box, one of Belfast's principal arts and entertainment venues.

The roof is covered in natural slate with blue-black ridge tiles, lead valleys where the building meets its neighbour, and two smooth-rendered gable chimneystacks at the north end, each with a corbelled bellcast coping and three clay pots. Deep moulded eaves support ogee-profile cast-iron rainwater goods. The external walls are finished in painted smooth render with a torus-moulded plinth, a continuous projecting flat sill course at ground floor level, a continuous ogee-moulded sill course at first floor, and a moulded string course above the first floor windows.

The ground floor windows are largely intact and are arranged as a Venetian composition set within a pointed arched frame enriched with barley-twist colonettes rising to small carved capitals from which paired segmental arches spring. Each frame is surface-fixed to a single sheet of replacement glazing. Decorative surface-fixed roundels are positioned above and between all ground floor openings. According to Patton, these roundels contain carved shamrocks, thistles, an eagle, a rose, and a motif of three barrels — emblems of the various breweries whose goods were distributed from the building. First floor windows are segmental-arched 2-over-2 timber sashes with horns.

The principal east elevation is the architecturally significant façade. To the left is the main entrance, which has replacement double timber panelled doors surmounted by paired segmental-arched glazing panels with a glazed roundel above containing the painted inscription "18". The entrance is contained within a segmental pointed arch with a torus-moulded architrave. To the right of the pedestrian entrance is the former carriage arch, now used for pedestrian access to Nos 20 and 22 only. This segmental arch contains double diagonally-sheeted entrance doors with cast-iron strap hinges and replacement external painted steel gates; a deeper moulded architrave frames a decorative figuratively carved key block at its centre. Three windows sit to the left of the carriage arch. Five first floor windows are positioned directly above their respective ground floor openings.

The south gable is attached to a modern three-storey red-brick extension, noted as being of no interest. The west elevation is abutted at ground floor by a single-storey extension connecting the main block to a modern five-storey block to the west; this single-storey extension is partially glazed where it meets the original building, providing natural light to the ground floor rooms of Nos 20 and 22. At first floor on the west elevation, an exposed section contains four square-headed 1-over-1 timber sashes to the right and a projecting box bay window to the left with a leaded flat roof. The bay comprises 2-over-2 horizontally divided timber sashes on the north and south faces and paired 2-over-2 horizontally divided timber sashes on the west face. To the east side of the glazed lean-to roof, a paved walkway with a mild steel handrail provides external access for maintenance purposes. The north gable is smooth rendered, fully painted, and carries a monochrome mural.

The building sits on a city centre site on the west side of Hill Street. It is street-fronted directly onto a paved footpath, with original cobbles surviving in the street surface. It is enclosed to the south and west by adjacent buildings. Car parking is provided to the north, bounded by metal railings separating it from Exchange Place.

Although much of the interior has been remodelled and substantial amounts of interior detailing have been removed, a considerable amount of historic fabric survives. The building is regarded as a good example of the type of warehouse characteristic of this early part of Belfast, connected directly to the city's early commercial and industrial history.

Hill Street itself — a narrow street running between Waring Street and Talbot Street — first appears on a 1757 map of Belfast as an entry off Waring Street. It was originally known as Pott-house Lane, owing to the presence of a pottery shop. By the time of the 1822 map of Belfast, published in George Benn's The History of the Town of Belfast, the street had taken its current form, lined with private dwellings, a foundry, and, in the mid-to-late 19th century, numerous public houses and licensed premises.

The earliest firmly documented occupant of the building is a Mr Robert Atkinson, a commission merchant, general agent and broker resident in Holywood, recorded in the 1852 Belfast Street Directory. Griffith's Valuation of 1859 recorded Atkinson's stores and offices valued at £83, with the lease held by a Mr Edward D. Atkinson. In 1866 the lease passed to a Reverend Canon Babington, and in 1871 the front of the building was completely rebuilt, resulting in the current façade and an increase in the warehouse's rateable value to £77. It is possible the building has an even earlier history: the 1843 Belfast Street Directory records a Mr Henry Steen, a provision merchant, operating from premises on Hill Street next to Elliot's Court — the same location where Atkinson was recorded a decade later — though the connection cannot be confirmed given the extent of the 1871 refronting.

Atkinson continued to occupy the warehouse until shortly before 1900, when Bass, Ratcliff and Gretton Ltd, English brewers headquartered at Burton-on-Trent, acquired the property (the company was founded in 1777 and continues to manufacture beer under the name Bass). By 1896 an additional store and offices, valued at £30, had been constructed to the rear. A Belfast Revaluation plan from around 1900 depicted a large L-shaped rear return containing a stable block used for delivering licensed goods. This rear block has since been demolished. At the revaluation the warehouse was increased in value to £150; the valuer noted it was fitted with gas fittings and had been purchased from Robert Atkinson for £2,000.

Bass, Ratcliff and Gretton continued to occupy the Hill Street site into the mid-20th century. The rateable value was reduced to £130 in 1909 for reasons not recorded, then raised to £166 in 1921 when the upper floor workrooms were leased to an Arthur McKinney — possibly the linen merchant of that name recorded at 4 Sandhurst Road in the 1918 Belfast Street Directory, though this cannot be confirmed. The Annual Revisions ceased in 1930 with no further change to the value; the First General Revaluation of property in Northern Ireland in 1935 set the value slightly lower at £140. The warehouse survived the heavy bombardment of the Belfast Docklands in the 1941 Blitz.

By the time of the Second General Revaluation, which commenced in 1956, Bass had vacated the warehouse but continued to lease it to other occupants. The building was by then subdivided into two addresses: No 18 (the upper floor), occupied by Irwin and Campbell Ltd, a Scottish metal supplier, valued at £96; and Nos 20–22 (the ground floor), used by David Bell and Co Ltd, valued at £268 by the end of the revaluation in 1972. First Survey records indicate that by the 1980s the ground floor windows onto Hill Street had been blocked up while Irwin and Campbell still occupied the building.

The building was listed in 1981, at which point it was in use as offices across three addresses — Nos 18, 20 and 22 Hill Street. The stable block to the rear was demolished in the late 20th century when the modern rear extension was constructed. Office use continued until 2006, when the current occupants acquired the building and converted it into the Black Box arts and culture venue, described on its own website as "a home for live music, theatre, literature, comedy, film, visual art, live art, circus, cabaret and all points in between."