Castlehill House, Castlehill

Castlehill House, located in Castlehill, dates from the late 18th century and has had later additions. It was extensively restored in 1993 by Simpson and Brown. This is a three-storey, three-bay town house featuring classical details. The building is constructed from rubble with ashlar dressings, lime-washed, and has a slate roof. It has rusticated quoins, ashlar-coped skews, and corniced end stacks. The windows are ashlar-margined with 12-pane timber sash and case glazing.

On the northeast elevation, there is a central stuccoed porch at the ground and first floors, added around 1853-1854. This porch features a pilastered and corniced doorpiece and a main cornice that masks the original Venetian windows on the ground and first floors. A bay to the left is obscured by the entrance and stair leading to St Roque's Halls. A single-storey flat-roofed passage linking the house to the church was added around 1950.

The southeast elevation has a prominent projecting three-bay bow at the center, with the central bay being blind. It has a battered concrete base and small windows at the ground floor with a linking lintel course. There is a central shouldered wallhead stack with an oculus, and a single window on all floors at the bays to the left and right, along with two canted dormers.

Inside, the interior remains largely intact, including cornices, joinery, and some chimneypieces. There is an original spiral stair with a stone newel at the ground floor and wrought-iron balusters above, as well as a later spiral stair with ornate cast-iron balusters providing external access to the first floor.

The property is enclosed by a coped rubble boundary wall at the front, which is part of a similar wall associated with St Roque's Hall and St Paul's Cathedral.