23 Clarendon St, Londonderry

23 Clarendon Street is a mid-terrace, two-bay, three-storey red brick townhouse with an attic over a basement, built in 1862–63 and designed in the Georgian style to match the adjoining Nos. 25–27, which were built slightly earlier between 1853 and 1856. The listing extends beyond the house itself to include the railings, plinth wall and the mews building to the rear. The building was originally constructed as a private residence for Forrest Reid, a local solicitor who also owned Nos. 25–27, and was first occupied by Thomas Reid before Forrest Reid took it as his own home in 1865. It was converted to office use in 1984 and is currently used as accountancy premises, though its original character and much of its original detailing survives despite some modernisation of the interior. The roof was reslated during a renovation in 2001.

The house sits within the Clarendon Street Conservation Area and forms part of a group of twelve early to mid-Victorian townhouses lining the south side of Clarendon Street, sharing group value with Nos. 5–21 and Nos. 25–73 (excluding No. 53), the whole terrace having been built over a twenty-one year period. The street was originally known as Ponsonby Street, named after the Rt. Rev. Richard Ponsonby (1772–1853), Bishop of Derry and Raphoe, but had been renamed Clarendon Street by at least 1853 in honour of George Villiers (1800–1870), the Fourth Earl of Clarendon and Lord Lieutenant of Ireland between 1847 and 1852.

The building is rectangular on plan with a projecting rear return. Its principal elevation faces north onto Clarendon Street. The roof is a pitched slate roof with black clay ridge tiles, a single dormer to the rear, and a large brick chimney stack rising from the east side, centred on the ridge and topped with seven clay pots. Cast-iron guttering and circular downpipes serve the front elevation.

The principal north elevation is laid in Flemish brick bond. The basement level is rendered and terminates at a string course at ground floor level. The entrance doorway has a three-centred arch opening with a moulded cornice supported by Doric order columns flanking a painted timber four-panelled door, above which is a single-pane overlight. The entrance is approached by five steps, the bottom two of which project beyond the boundary wall onto the pavement. All window openings on this elevation are square-headed with painted cement rendered reveals and painted sills. Unless otherwise noted, all windows are six-over-six timber sliding sashes. At ground floor level there are two diminished windows to the left of the door. The first and second floor each have two windows, though these upper-floor openings are not aligned with those below. The basement has two casement windows positioned directly below the ground floor windows.

The east and west side elevations are abutted by the adjoining Nos. 21 and 25 Clarendon Street respectively.

The south rear elevation is cement rendered and rises three storeys over a basement. To the left there is a cement rendered, pitched roof rear return of four storeys over a basement. To the right of the main block's rear elevation there is a small single-storey lean-to boiler house. In the right bay of the main block, the basement has a modern uPVC door with sidelights, and there is a single six-over-six timber sliding sash window at ground, first and second floor levels. Above this bay there is a pitched roof timber-clad dormer containing a single six-over-three timber sliding sash window. The left bay of the main block is fully abutted by the rear return.

The fenestration on the south gable of the rear return is irregular. At basement level there is a single casement window. At ground floor there is a single two-over-two timber sliding sash window. At first floor there is a canted timber oriel window made up of margin-paned timber sliding sash windows on each facet: a two-over-two round-arched sash, a four-over-four segmental-arched sash, and a further two-over-two round-arched sash. At second floor there are two diminutive one-over-one timber sliding sash windows, and at third floor a single six-over-three timber sliding sash window. On the east face of the rear return there is a flush fire door at basement level, a diminutive one-over-one timber sliding sash at first floor, and a round-arched margin-paned timber sliding sash at second floor; the upper floors of this face were not visible at the time of survey. The west face of the rear return is blank.

The front of the property is set behind a low rendered wall with a painted stone coping surmounted by replacement black painted metal railings. To the rear there is an enclosed yard. Also within the curtilage, and contributing to the interest of the listing, is a two-storey mews building with a pitched natural slate roof, whitewashed stone walls and brick dressings. On the mews building's north elevation there is a vertically sheeted timber door to the left of centre, with a square-headed three-pane overlight above, and two square-headed timber louvred openings at first floor. The east elevation is blank. The west elevation is fully abutted by the mews building of No. 25 Clarendon Street. The south elevation has a square-headed timber louvred opening to the upper left and a vertically sheeted timber opening to the upper right; the ground floor of this elevation was not visible at the time of survey.

Materials throughout are as follows: the main roof is slate with cast-iron rainwater goods to the north and uPVC to the south; the rear return roof is also slate; walling is brick to the front and rendered elsewhere; windows are timber to the north and south elevations, with some uPVC to the south.

The house stands as a representative and noteworthy example of the mid-19th century expansion of the city. The Clarendon Street area had been entirely rural hinterland as recently as 1830, when the first edition Ordnance Survey map of the townland of Edenballymore recorded virtually no development in the area and the city's built streets extended no further than Waterloo Place, Abbey Street and William Street. The only significant buildings north of the walls constructed in the early decades of the 19th century were isolated institutional structures such as the Londonderry Infirmary, the Lunatic Asylum, and Foyle College. The only surviving domestic building in the area from before the Victorian development is Foyle Cottage, a Regency house of around 1815, which writer Calley described as "a pleasing composition which offers a gentle rebuke to some of the exuberance of later nearby buildings … one of its pleasant features is that it opens a gap in the long terraces." Robert Simpson, writing in The Annals of Derry in 1847, noted that the entire district then covered by Great James Street, William Street, Little James Street and the surrounding lanes had originally comprised meadow ground without a house.

Development of Clarendon Street began in the late-Georgian period and accelerated into the Victorian era, driven by substantial growth in the economy and population of the city. John Hume records that during the period 1825 to 1850 reconstruction within the walled city took place alongside the first development of housing outside the walls at Bogside and Edenballymore. A plan of Londonderry dated 1847 depicted the proposed layout of the street — then still labelled Ponsonby Street — at least a decade before it was completed. In 1851, building ground on Clarendon Street, Queen Street and Patrick Street was advertised to let in perpetuity by Skipton & Miller. Griffith's Valuation recorded that only nine dwellings had been constructed along the entire length of the street by 1856, with further leases for ground on the northern side advertised that same year. Clarendon Street, Great James Street and Queen Street followed a geometric street pattern characteristic of Georgian town planning, and their development represented the most ambitious programme of urban planning in Londonderry since the construction of the walled city between 1613 and 1619. The uniform rows of three-storey townhouses swiftly became the residence of the city's merchant and professional classes.

No. 23 was originally valued at £40. By 1901 the house was occupied by a Ms. Jane Scott, who derived her income from investments; the census return of that year described the property as a first-class dwelling of ten rooms with a stable as its sole outbuilding. Forrest Reid continued to own No. 25 and many adjoining buildings until his death in 1888, at which point his holdings passed to the executors of his will. By the First General Revaluation of 1935, ownership of No. 23 had passed to a Mr. J. B. Smith and the assessed value had risen to £42; the house remained solely a private dwelling at that date. By the 1950s it had been partially converted into a medical surgery for a Dr. J. E. O'Donnell. By the end of the Second General Revaluation (1956–72) Mr. J. B. Smith was still recorded as owner and the value had been slightly increased to £46. In 1978 the Department of the Environment designated Clarendon Street and the surrounding streets a Conservation Area, defined as "an area of special architectural or historic interest, the character of which it is desirable to preserve or enhance." No. 23 was listed in 1979 and fully converted to office premises in 1984. Calley, writing in 2013, described Nos. 23–27 Clarendon Street as terrace houses "differing from their neighbours in that they have stone steps over basement wells leading to the doors, giving them the most elegant approaches of any houses on the street." The majority of mid-Victorian townhouses on Clarendon Street have since been converted to professional office use; few remain in residential occupation.