Long Barn at Pencoed Castle

The Long Barn at Pencoed Castle is an exceptionally long barn built of rubble with quoins and thick walls, topped with a modern tiled roof that undulates at the northern end. The structure consists of two in-line threshing barns that serve the large estate farm, along with a projecting two-storey cross-range at the southern end, which includes a granary and cowhouse. The northern half is narrower and has an independent roof.

The southern end contains the earlier parts of the barn, featuring a depressed and chamfered arched doorway flanked by rectangular windows with dressed stone surrounds. To the right, the taller gable end of the storied range has outside stairs, possibly for a goose nest at the base, and a timber-framed window beside the loft door. The southern end has three timber-framed windows, one of which is blocked, and relieving arches over two blocked doorways, along with a cart entrance on the eastern gable end. Both sections have slit ventilators and full-height barn-door openings on each side; the northern part has modern doors and an off-centre position. The eastern side has a square-headed doorway opposite a late medieval one on the western side.

The king post roof structure of the southern barn dates to 1879, while the northern barn reuses old timbers and was partly lofted, divided by stone partitions. The slit ventilators feature cambered heads with voussoirs to the splays. The cross-range retains a loft.