Plas Trefilan

Plas Trefilan is a two-storey building constructed from rubble stone, originally roughcast, and topped with a pyramid slate roof featuring deep eaves and paired brackets. There is one rendered stone chimney stack to the left of the apex, with another that was originally located to the right. The building has a square plan and a three-window range, with a raised plinth and a basement under the southwest angle. The windows are 12-pane sash types with stone voussoirs. The central entrance features a six-panel door, two of which are glazed with lozenge tracery, complemented by a similar lozenge tracery overlight. A fine painted timber trellis porch enhances the entrance, showcasing an arched entry, leaf-pattern spandrels, lozenge pattern uprights and top rail, dentils, and paired brackets, with the sides featuring intersecting diagonals that create a central lozenge shape.

On the west side, there is a 20th-century basement door (the basement was previously only accessible from inside), two 12-pane sash windows on the ground floor, with the left window replacing a 19th-century bay window, and one first-floor sash window to the left. The east side has a ground floor 20th-century French window on the left, replacing a previous window, and a 12-pane sash window to the right, along with another 12-pane sash window on the first floor to the right. An added northwest service wing has a hipped roof to the north and an altered west lean-to that was formerly a dairy. The rear wall of the house is partially rendered.

Inside, the building features a centralised plan with a broad entrance hall that has an elliptical arch. The staircase has stick balusters and a curved return to the landing. The landing is surrounded on three sides by a plaster-moulded circle in the ceiling that encircles a conical tall roof-light reaching near the roof apex, constructed of lath and plaster. The ground floor has six-panel doors, and the east rooms are combined into one space, while the southwest room has shutters. There is a rear panelled door with an overlight.