Dunboe House, 133 Quilly Road, Castlerock, Co. Londonderry, BT51 4UB

Dunboe House is a detached, symmetrical, three-storey-with-basement Georgian-style former Glebe House, built in 1774 by Michael Shanahan — architect to the Earl Bishop of Derry — at a cost of £700, as a residence for the Archdeacons of the diocese. The building fell into near-ruin before being extensively restored and repaired in 1821 following the arrival of Archdeacon Monsell. The Ordnance Survey Memoirs record that he "made great improvements about it and rendered the house a good family residence." The house is characterised throughout by symmetrical, balanced proportioning and by the austere, plain detailing typical of late 18th and early 19th century architectural principles. Its interest is further increased by the adjacent outbuildings and its unspoiled rural setting, and the building displays evidence of physical evolution across two centuries of domestic use.

The main house faces south and is rectangular on plan, three bays wide and three storeys over basement. To the north rear elevation there is a full-height advancing central stair bay with a hipped roof. A single-storey pitched return to the west, dating from around 1890, abuts former single-storey outbuildings of around 1840, which have largely been converted and refurbished. Further detached outbuildings to the west date from around 1830. The roof is pitched slate with black and grey roll-moulded ridge tiles. There are two brick gable chimneys, each carrying five octagonal decorative clay pots. Rainwater goods are replacement uPVC, mounted on plain timber fascia, and the eaves are formed by timber-sheeted overhanging boxed eaves. External walling is painted ruled-and-lined render.

Window openings are regular and square-headed, reduced in height on the upper floor, with projecting painted tooled-stone sills and plain reveals. Windows are generally original 6/6 timber sashes without horns, with 3/6 sashes to the basement and second floor levels unless otherwise noted.

The symmetrical principal south elevation is five openings wide. To the centre is a recessed round-arch doorway containing a replacement six-panelled raised-and-fielded timber door, flanked by plain pilasters on plinths that rise to scrolled and foliated console brackets carrying a projecting moulded cornice. There is a plain glass fanlight above the door. Sandstone steps to the main entrance extend over the basement channel below, flanked by curved and capped painted dwarf walls.

The west elevation is largely blank, with a partial area of painted cement render to the left and recently relimed ruled-and-lined render to the right.

The north elevation is three openings wide, with single windows vertically aligned on each floor. The square-plan full-height advancing central bay has a hipped roof and windows at half-landing level. The right cheek is blank; the left cheek has a single timber casement with frosted glass insert at ground floor level, reportedly the former entrance doorway. To the immediate left of the central stair bay, at first-floor level, there is a diminutive oculus and a four-paned casement window. The lower window to the far right of the main elevation has no sill and a painted timber lower section; according to the owner, this window can be opened and the panel lowered to create a doorway.

The east elevation is blank at upper levels, but at ground floor level it is abutted by a pitched single-storey extension of around 1890, detailed to match the main house. This extension abuts and links a line of former outbuildings to the east, dating from around 1840. There is a single window to the right cheek and a triple opening to the left cheek, containing replacement full-height sashes with a twelve-pane door to the centre. The south-facing gable of the east outbuilding, which abuts to the right side, contains a matching window and door arrangement.

The east outbuilding range is roughcast, single-storey, and four bays wide, with a pitched slate roof and two brick chimneys — one plain chimney to the centre ridge and a tall one along the eastern wall. Rainwater goods are uPVC on plain timber fascia. Window openings are small, squared and irregular, generally retaining original multi-pane casements with some replacements, and there is a replacement timber door with a six-paned glazing panel. The north gable is blank; the south gable is as described above. The west elevation has a low window and the upper opening is timber-sheeted. The east elevation has three replacement casements at higher level and a large ten-paned casement with a stone sill at low level, along with two doors, the right-hand one being a timber-sheeted and braced half-door.

The outbuildings to the west are similarly detailed. The west elevation of the main gabled structure comprises two 1/1 timber casements, a modern metal garage door to the right of centre, and large double-leafed timber-sheeted sliding doors to the left. The remaining elevations are blank except for ventilation holes to the east side. A small mono-pitched outbuilding to the west has no rainwater goods, a brick chimney, three timber-sheeted doors with original iron ironmongery, an original 6/6 sash to the north elevation, and a diminutive four-pane original casement to both the north and south elevations.

Regarding alterations documented by researchers: the flanking office wings behind the house indicate, according to Rowan, that the entrance was originally on the north front. Girvan notes that the 1820s restoration also affected the ground-floor interior, where the internal doors are of early 19th century date. In the mid-19th century, alterations were made to the drawing room to the west, a marble fireplace was added, and it is thought that one of the outbuildings was incorporated into the main body of the house. The house was listed in 1977, renovations to the exterior took place in the late 1980s, and further work was carried out to the roof and windows in 2007–8.

The house has a well-documented occupancy history. The first occupant was Archdeacon John Stanley Monck, commemorated by a tablet in the parish church of Drumachose, Limavady. Griffith's Valuation of 1856–64 records the occupier as the Venerable Archdeacon A. W. Edwards, who held the freehold of the house, a steward's house, office, and over 52 acres of land, with buildings valued at £28. The house then passed to the next Archdeacon, Charles Galwey, but following disestablishment it was sold, with John Steen becoming occupier in 1876. By 1886 the valuation had fallen to £15. The 1901 census lists the dwelling under three separate occupiers: nine rooms occupied by John Steen JP, a retired farmer, and his wife; three rooms by widow Mary Anne Watson and her son, a dental surgeon born in County Westmeath; and three rooms by unmarried woman Isabella Kerr and her sister, who lived from the income on their savings. In 1921 the house was taken over by Major James A. Willington of the Willingtons of Tipperary, who had perhaps left his estates in the south of Ireland in anticipation of partition.

The house is situated in a rural farmland setting to the south side of Quilly Road, between Castlerock and Coleraine, on a mature, elevated site overlooking lawned gardens and bounded by extensive woodland. The south-facing entrance is accessed via a replacement stone wall and piers leading to a gravel path which sweeps westward, terminating in an expansive forecourt. The original entrance is reputed to have been on the north elevation, via the lower level of the projecting central bay, with steps ascending into the main hallway. A combination of rubblestone and roughcast screen walls to the east and west of the house commonly feature rounded archways with decorative wrought or cast iron gates. The eastern yard is fully concreted; all remaining paths are gravel. The remnants of a previous range of outbuildings form the eastern wall of the east yard.