Wern Tarw is located to the north pencoed and is a grade II listed property. The western unit of the house is C17 and represents the outer room of a hearth-passage house. The hall to the east was demolished and replaced in the early - mid C19 by a new range. The roof was raised at the same time.

The house comprises of a long 4-window range of rubble masonry under a slate roof with 2 end stacks and a ridge stack. The western unit is the earliest part of the house and is constructed of walls c 1.5m thick. It would have constituted part of a one and a half storey building. The west gable stack, rebuilt in blue brick, is in its original position. There is a simple planked door to the front (S), at the eastern end of the C17 unit, which opens into a passage. To its left is a large raked buttress, the top of which supports a flat timber canopy which acts as a porch. To the L of the buttress is a deeply recessed 3-light wooden window with ovolo mouldings and very small panes. It is slightly skewed relative to the opening which has a timber lintel.

The C19 remodelling involved the addition of a symmetrical 3-window range to the east and the raising of the roofline to form 2 storeys. A 2-light wooden casement with small panes was inserted above and partially into the C17 unit at first-floor level. The range to the east has a centrally-placed panelled door and a blind window above, both flanked by 12-pane sash windows with sills but no lintels.

The east gable end of the house has no openings. The west gable end has no openings above the level of the cowhouse. The rear has been partially cut into the hillside. There is an outshut to the rear of the C17 unit and one blocked opening is visible. There are single storey lean-tos to the rear of the C19 range; that to the east has a brick stack in its north-east corner.

The cowhouse, adjoining the western side of the house, is of masonry rubble under a corrugated iron roof. It has a 4-door front, although there may have been a 5th door to the west where the wall has collapsed. The doors are planked where they survive. There is a centrally-placed casement window with a brick sill but no glass. In the attic is a loft opening at the east end and a smaller opening towards the centre. Joints in the masonry suggest that the building was raised to form the loft and was extended to the east. This is further suggested by the east doorway which has a flat head with voussoirs, unlike the others which have simple wooden lintels. Thus the cowhouse may originally have been a free-standing single-storey building with 3 doors. The rear is built into the bank so there is direct access into the hayloft. There are 2 openings, the east one with planked doors, the west one under a brick head.

Source: Cadw Listed Building database (Ref: 19049).