Barn and attached ranges at Wallas Farm

The barn and attached ranges at Wallas Farm are constructed of rubble with dressed quoins and feature a Welsh slate roof. The barn is oriented north to south and has overhanging eaves that extend over deep off-centre porches, with the western porch being larger than the eastern one. It has wide timber lintels above opposing boarded double doors, which are topped by segmental relieving arches. There are ventilation slits at two levels and a further boarded opening on the northeast side. Stone steps lead to a loft at the left end of the courtyard frontage, which has a boarded door and a small light below. Attached to the north is a low single-storey four-bay range with a pitched roof and some dressed stone on the altered front. A lean-to three-bay piggery steps down from this range. An open cart shed is attached to the barn on the south side. There is a later extension to the porch on the west side.

Inside, the barn features a five-bay layout with king post trusses and braces that support the principal rafters, which rise from the jowelled foot of the king post. There are two rows of trenched purlins on each side, and timber lintels above splayed vents. The north end is floored and has a boarded partition with a door leading to the loft. The timber threshing floor that was present when the barn was first listed in 1989 is no longer there, and stone flags are now present to the south. King post roofs are also found in the ranges to the north and south.