Old farmhouse at Trewyn Farm

The Old Farmhouse at Trewyn Farm is a 17th century building constructed from red sandstone rubble with a stone tile roof. It is a single-storey, single-depth rectangular structure featuring three rooms, with the right-hand room having a separate entrance. The main elevation includes a plain plank door on the left, positioned in a lobby entry next to the stack. To the right of the door is a small two-light casement window, and a smaller casement for the central room. The right-hand room has a blind wall. The stone roof is partially damaged and has a stone stack on the left gable, showing weathering that suggests it may have originally had a thatched roof. The left gable is blind, while the right gable features a doorway with an overlight, a low window with a drip over, and a four-pane casement window in the gable above. The rear wall is also blind.

Inside, the house appears to have been an open hall, as the roof is heavily smoke blackened. There are three small rooms, two of which are interconnected, while one is entered separately. A stack has been inserted on the south gable, with remnants of a 19th century iron range, and to the right of this is the base of a copper. The interior features two raised cruck trusses with ties and heavy trenched purlins, indicating that the front wall has been heightened. There are also slight secondary rafters, all of which are smoke blackened. This includes timbers added when the pitch of the roof was changed for the stone tiles, suggesting the chimney was already in place when the roof was still thatched. The second and third rooms could not be properly inspected.