Long Range of outbuildings to SW of Farmhouse at Treginnis Isaf, including attached walled enclosure

The Long Range of outbuildings to the southwest of the farmhouse at Treginnis Isaf dates from around 1880, although a second walled enclosure is shown on the 1840 Tithe Map. The main range is approximately 30 meters long, constructed of rubble stone with a hipped grouted slate roof, and was under restoration in 1989 for use as dormitory accommodation. It features eight small square loft lights with timber lintels and 20th-century paired casements. The ground floor includes four large cart entries with heavy timber lintels, flanked by stables at each end. The stable on the right has a single renewed casement, while the left stable has a wide doorway and one window. The southeast angle is marked by Caerbwdy stone quoins. The two cart entries on the right are partially blocked, one with a door and the other with a door and window. Inside the left cart entry, there are stone stairs against the cross-wall. The rear of the building has five loft windows and five doors with brick heads.

Behind the main range is a yard that contains a rubble stone gabled cow-shed at the north end, which has two doors leading to the yard and one door for the feed passage at the east end. This structure was under reconstruction in 1989, with the roof cladding removed and a large brick arched opening in the west wall. High rubble walls enclose the west and south sides of the yard. The west side has been altered for a 20th-century entry and has two concrete-headed windows inserted in 1989, although the original brick cambered-arched cart entry remains intact to the right. Buildings were under construction within the yard in 1989. The south side features three doors leading to a lower yard, all added in 1989.

To the south, there is a large enclosed yard surrounded by rubble walls. Attached at the southwest angle is a stone outbuilding with a hipped grouted slate roof and a brick ridge stack. This outbuilding has Caerbwdy stone quoins at the northwest angle, one door at the north end, two windows on the west side, and a south end lean-to with one window on the west side, all featuring cambered brick heads. The lean-to is part of a malting house range against the south wall of the enclosure, which has a grouted slate lean-to roof and five openings in the south wall, including one stone stack and a door at the east end.

A sale document from 1885 refers to a "granary 50 feet long with cowhouse beneath for 14 cows," but the current building is larger, and there are no remaining signs of its use for cattle.