Former farmhouse and cowshed at Trefynor Isaf

The former farmhouse and cowshed at Trefynor Isaf is a historic building featuring whitewashed cob or clom walling with some rubble stone, topped by a corrugated iron roof that was originally thatched. The chimney has been removed. This one-storey structure, which once had a loft, has a north front that includes a hornless 16-pane sash window on the left, a ledged door to the right of center, and a small boarded square window to the right. The east end wall is made of rubble stone, while the west end has a large loft opening with an oak lintel. The rear of the building has an added rubble stone lean-to with a slate roof and five doors, the second of which leads to the house's rear door, while the others provide access to pig-sties. Stone piers are present between these openings.

To the left, there is a cow-house that is situated down the slope, constructed of whitewashed rubble with a slate roof. It features a ledged door at the front and a 20th-century window to the left. There is also a 20th-century brick addition to the left, with a ledged door on the east end wall. The rear of the cow-house has one 20th-century window to the right and one central window, which is partially blocked by the added lean-to on the left.

Inside the house, there are two pegged collar trusses with feet that are scarfed onto long wall-posts, along with double purlins. The east end features a chimney-beam that spans across, supporting a hood that was originally wicker but is now clad in zinc. There is a door to the cow-house on the right. Additionally, two beams at the upper end support the former loft floor, with one beam showing mortices for a former partition. A large west loft window has a crude timber arched window frame that has been inserted. The cow shed has a four-bay roof from the 19th century, dated 1898.