Trethin

A house dating from the late 16th or early 17th century, with a parlour wing added in 1655 as recorded by a datestone. The building is constructed of stone rubble, partly rendered, and is roofed in asbestos slate.

The structure sits on sloping ground and originally comprised a hall and parlour with kitchen, heated by gable-end stacks. The hall occupied the higher left side with a stair projection to the front lower right. The kitchen stood on the right, with a gable-end stack. A two-storey porch was added to the front in the early 17th century. In 1655, Matthew Vivian added a parlour wing projecting forward from the higher left end of the hall, heated by a side lateral stack.

The building rises to two storeys with an asymmetrical four-window front. The front elevation shows the parlour wing on the left with a four-light mullion window on the ground floor bearing the initials 'MV' (Matthew Vivian) in labels. The inner side wall of this wing has a three-light mullion window on the ground floor and a four-over-eight-pane sash on the first floor within a three-light mullion surround. The hall section on the left features a large 20th-century window on the ground floor and a two-light casement above, with a three-light greenstone window lighting the stair projection. The two-storey porch has a chamfered granite surround to the doorframe with pyramid stops and a 20th-century door, with a two-light mullion window on the first floor. The kitchen to the right is lit by a 19th-century two-light casement on the ground floor and a six-pane sash on the first floor. Gable ends have asbestos slate roofing with lean-to outshots on the right-hand gable and to the rear of the hall.

Internally, the through passage features a thick cross wall on the higher side and a partition on the lower side extending to first-floor level. The entrance to the hall has a timber doorframe with a segmental arch and chamfer from the late 16th century, with stops now eroded. The hall fireplace displays a chamfered granite surround with an adjoining door leading into the parlour wing, which has an ovolo-moulded timber doorframe dated to circa 1655. A further ovolo-moulded timber doorframe gives access to the outshot to the rear, with a reused frame showing runout stops with double nick at the pointed end. The stair has a shouldered timber doorframe with chamfer and runout stops. Several ceiling beams in the kitchen have been reused. The newel stair is carpeted and accessed through a chamfered doorframe leading to the room above the porch.

The parlour wing was added by Matthew Vivian in 1655 and underwent partial 19th-century remodelling. The front room retains its original function, heated by a side lateral stack. The granite lintel above the fireplace bears the carved inscription 'M 1655 V'. The granite jambs are unusually hollow-chamfered and moulded on both sides, as the fireplace projects into the room, with ball and pyramid stops on the inner side and diagonal stops on the outer side. The rear room has been partly altered with a partition and 19th-century stair inserted.

The roof structure above the porch was not fully accessible, although the principals show slightly curved feet. The two trusses above the hall feature trenched purlins (the lower set possibly threaded) with morticed apices and a diagonally set ridge. The collars are dovetailed with a single notch. The kitchen range contains one truss of approximately 18th-century date, with the apex and collar partly halved, lap-jointed and pegged.

Copies of the inventory and will of Matthew Vivian, dated 1664, are held by the current owners.