Trewoon Manor House

Trewoon Manor House is a roofless ruin of a manor house, originally built in the 16th century and extended in 1634 (as recorded by a datestone) for Henry and Gertrude Carnsew. It was remodelled slightly in the 18th century. The building is constructed of granite rubble with granite dressings.

The house follows an irregular L-shaped plan, with a 16th-century hall range on the left, a former through passage to its right, and a cross parlour wing projecting forward on the right. The roofline is defined by a half-hipped front to the parlour cross wing, a hipped end on the left, and a gable end between the hall and parlour sections. The large hall features a large external lateral stack at the front. To the left of the hall is a possible former inner room, containing what is probably a resited 16th or 17th-century doorway at the front. The parlour wing may be truncated at the rear, where a probable reset datestone of 1634 appears in the wall.

The exterior presents two storeys on its north-north-east front. The long, low hall range occupies the left side, with the parlour front built forward slightly on the right. The hall range contains a probable 16th-century 4-centred arched chamfered doorway with pyramid stops towards the left, a later (probably 18th-century) doorway roughly midway with a straight joint marking a former hall window position to its left, a large external lateral chimney breast towards the right, and a probable 17th-century chamfered doorway with segmental head on the right. First-floor window openings towards the left and a blocked opening left of the chimney breast are probably 18th-century insertions. Two window openings cut into the chimney breast are probably 19th-century additions. The parlour front features a central 17th-century moulded 4-light window to each floor, with a square hoodmould over each window, though the mullions have been removed. The relatively thin rear wall of the hall range contains openings that appear to be 18th-century. The left-hand wall of the rear projection of the parlour wing has a ground-floor doorway near the angle and a loading doorway above and slightly to the left. The ground-floor doorway has double chamfered jambstones, probably in situ, and a reused moulded and stopped probable jambstone serving as a lintel. The right-hand wall of the parlour wing contains some openings that were not sufficiently accessible at the time of survey to permit accurate description.

The interior was substantially decayed at the time of survey in October 1987, with 18th-century floor and roof structures falling in and making access difficult. Principal features identified include a large hall fireplace, partly fallen, featuring a hardwood lintel and a domed oven behind each jamb (probably partly rebuilt in the 18th century). A 17th-century chamfered granite fireplace serves the chamber over the hall, supplied by a flue in the cross wall between the hall and parlour ranges. A moulded granite cornice is visible high up in the same wall. A similar 17th-century fireplace exists in the chamber over the parlour, backing onto the same wall, and an ovolo-moulded hardwood lintel sits over the parlour window. A chamfered granite fireplace occupies the rear left-hand corner of the parlour, with its far jambstones visible from the outside. The walls retain traces of limewash.

Trewoon was inspected and researched by Charles C. Henderson in the 1930s, with his notes recorded in Antiquities, Volume IV, held at the Royal Institution of Cornwall Library, Truro.