Barn with attached cart shed at Berthymaen

A rubble-stone barn with slate roof behind coped gables, set on a sloping site with large stepped boulder plinth to the downhill end. Facing the yard is a lintelled winnowing doorway, narrowed with brick jambs added to the R side, and with a boarded door. The doorway is flanked by 3 tiers of narrow ventilation strips, mostly blocked with brick. A small lintelled opening is at the R end. The L, downhill, gable end has a blocked lintelled opening to its loft above the lower cart shed. The cart shed, also of rubble stone with slate roof, has 2 brick segmental-headed doorways with replaced doors, and boarded loft openings beneath the eaves. The machinery store is lower again and is open-fronted with a central timber post and added metal gates.

To the rear, the cart shed has 2 boarded loft openings. The barn has a segmental-headed doorway to the threshing bay, of which the jambs are original but the arch is C19, with replaced boarded door. Above it is an inserted loft opening, to the R of which is a late C19 bearing box probably inserted to allow steam-powered threshing using a portable steam engine. The doorway is flanked by ventilation strips, similar to the front and mostly infilled. A doorway at the L, uphill, end is probably inserted for a small stable, and has a brick jamb on the R side and a boarded door. A later large shed is attached to the uphill gable end.

The barn has a 4-bay queen-post roof.