Barn at Pen-twyn Farm

The barn at Pen-twyn Farm is a 19th-century structure made of red brick laid in English bond, with a limewashed exterior. The yard side is covered with Welsh slate, while the rear slope features asbestos sheeting. On the yard front, there is a blind bay to the left of the porch, which contains two blocked slit vents. The small porch is supported by brick wing walls that are corbelled out to hold the roof, and it has double plank doors. This bay is mostly hidden by a later lean-to addition.

There is a cross passage entry into the byre, featuring an elliptical blue brick head. A second doorway, now blocked, has a window with a blue brick sill and elliptical head, along with a casement window that has a stone sill wider than the window itself. Another doorway with an elliptical blue brick head is also present. The right gable has a taking-in door for the hay loft, while the left gable includes a later lean-to below and a slit vent above.

On the rear elevation, double doors lead to the threshing floor, with a casement window above and a window on each floor at the byre end. The barn has several slit vents, but all are blocked and not visible from the outside. The eaves are supported on brackets, and the roof is plain.

Inside, the barn features a five-bay queen strut roof with three tiers of purlins and secondary rafters. Most of the timber is hewn, with a few sawn replacements. The interiors of the byre and granary remain unchanged.