St Patrick’s C of I Church, Carncastle, Larne, Co Antrim

St Patrick's Church of Ireland in Carncastle is an early 19th-century church of rustic charm set in a rural landscape, distinguished by an unusual octagonal spire. The building was constructed in 1815 with a grant from the Board of First Fruits as a simple rectangular structure with a western tower and spire. The chancel and vestry were added in 1862 to designs by Welland and Gillespie of Dublin. A Sunday school was added in 1992–93 to designs of H.S.L. Robinson, ARIBA, MRIAI, MBIM.

The church comprises a nave, chancel and western tower containing the entrance, with a projecting vestry on the north side of the nave and a modern school room on the north side of the tower. The south elevation displays the main architectural composition: the nave is constructed largely of grey stone boulders, the later chancel of random rubble blackstone with sandstone quoins, and the entrance tower is set back to the left with the chancel set back to the right.

The tower features circular openings containing louvres on three sides at the top, with the entrance-front opening positioned off-centre; immediately below is a blocked two-centre arch. The main entrance is a chamfered Gothic archway containing double doors of ledged timber with ornamented hinges. The tower is topped by a crenellated parapet supporting a slated octagonal spire—an unusual feature that is a rebuilding of the original spire circa 1970, executed following the general form of the original but lacking the original blind oculus details at the base. A weathervane crowns the spire.

The west face of the tower contains a pair of coupled lancets of Gothic Revival design (later insertions within what was originally a rectangular doorway), glazed with stained glass. The nave is roofed with slate in Bangor blue laid in regular courses between gable copings of sandstone, with a stumpy octagonal chimney at the right-hand extremity of the ridge. Cast iron guttering and downpipes serve the roof. Windows on the south and north elevations of the nave consist of two pairs each of coupled lancets of Gothic Revival design (later insertions) with sandstone dressings. These are glazed with lozenge-pattern cast iron glazing bars and clear glass quarries with red tinted margin lights.

The chancel roof and rainwater goods match the nave treatment. The east gable of the chancel has a three-light traceried window in Gothic Revival style with sandstone dressings and stained glass. One pair of small coupled lancets in the chancel contains lozenge-pattern leading and stained glass. The chancel is fitted with a flag pole mounted high on its wall with timber and iron brackets.

The north elevation shows the chancel side wall with a shallow rectangular out-shot containing a small Gothic arched window with lozenge-pattern cast iron tracery. The vestry projects forward from the north side of the nave with a gabled roof; its gable was built up from an original hipped roof, as documented in historical photographs. It features a small Gothic arched lancet with lozenge-pattern cast iron tracery in the gable and a doorway with shouldered lintel and sandstone dressing in its west side, containing a ledged timber door approached by sandstone steps with a modern tubular metal handrail. The vestry is constructed of random rubble blackstone. A Victorian iron lamp bracket with fluted globe-light is mounted on the wall at the right-hand extremity of the nave's south elevation.

The school room is a recent addition (1992–93) built of boulder masonry in imitation of the tower and nave. However, its lancet windows have cement surrounds applied as raised blocks, a technique not used elsewhere on the church and considered inappropriate. The roof slopes down from the nave in slate, served by cast iron gutters and downpipes, but the introduction of PVC soil and waste pipes at low level is inappropriate. The set-back gable at the west end is dressed with slate hanging, a construction technique also considered inappropriate to the building.

The church stands in a rural setting within its own churchyard, which also contains the ruined walls of a 17th-century predecessor church. A substantial rubble stone boundary wall fronts the main road with a set of modern iron gates; other boundary walling is either insubstantial or in partial collapse, supported only by later buttresses. The building lies within the area of an ancient monument (ANT35:14).

The font is of historic significance, having been used by Dean Swift in Ballynure Church during his incumbency in 1695. The listing extends to the church, gates, and boundary walling.