Trewethern Farmhouse

Trewethern Farmhouse is a two-storey stone rubble farmhouse dating from circa 1500 or earlier, substantially remodelled and extended in the early 18th century. The building is partly slate-hung above the ground floor on its left-hand side and roofed with asbestos slate. The roof arrangement was altered on the right side and to the rear right during late 20th-century re-roofing. Gable ends feature projecting wings, with a gabled projection on the front right. The building is heated by projecting stone rubble stacks with brick shafts on the left-hand gable end and rear right slope, and an axial brick stack to the right of centre serving the central room.

The earlier range survives on the right, containing one cruck truss dating to circa 1500. This roof truss is completely clean and probably once spanned an open hall, which may have contained a fireplace, or alternatively a first-floor parlour or solar. The original plan is uncertain. Early 18th-century remodelling is evidenced by a straight joint on both front and rear elevations to the left of the axial stack, and the right-hand range was increased in depth, probably by about 1.5 metres. The remodelled house comprised a three-room plan with cross passage and stair, probably located in a rear projection off the passage. The earlier range on the right became an inner room of considerable dimensions and by the mid-19th century had developed into a large kitchen with a dairy added in a projecting front wing and a small service room in a rear outshut.

The front elevation is regular with three windows. Fenestration is disposed to the left in the later range, with a projecting two-storey wing on the front right. The ground floor features two 16-pane horned sashes flanking a 19th-century entrance door, with a circa 19th-century porch having rendered piers and flat roof. Three 3/6-pane sashes occupy the windows above ground floor openings. To the right of the projecting wing is a second entrance with a 19th-century six-panel door in a lean-to stone rubble porch.

The interior of the 18th-century range features a circa late 18th or early 19th-century open-string stair with turned newels and ramped rail. The left-hand room contains a segmental arched opening with fluted pilasters and a circa late 18th-century chimney-piece. The earlier range on the right was remodelled in the 18th century. The roof structure above the right-hand range was altered during late 20th-century re-roofing, but earlier roof framing of five bays survives below, comprising three circa late 18th-century trusses with principals halved, lapped and pegged, with collars partly halved, lapped and pegged onto the face of principals and trenched purlins.

The truss towards the right-hand gable end dates to circa 1500 and features cruck principals with cranked collar and arch braces. The principals reduce above collar level to open mortices apparently intended to carry an upper tier of principals which appear to have slotted onto the back, though this upper tier is now missing and only part of an apparently unusual joint survives. The principals contain a tier of holes for threaded purlins well below the collars. There is no evidence whether the upper principals supported any form of ridge. One principal foot has been truncated, probably during late 20th-century modification of the relieving roof structure above, whilst the other has been boxed in.