This outbuilding, thought to have been built as a cow shed with lofted cart shed and stable, is part of Llandyfan House Farmstead (NPRN 407331). It is Grade II listed as part of the three-sided farm yard complex and because of its group value with Llandyfan House (NPRN 17508), Barn (NPRN 31617), Outbuilding (NPRN 31618) and St Dyffan's Church (NPRN 302028). The range is sited on a slope and is lofted at its lower end, with the upper end partly overlapping the barn.

The building is constructed of rubble stone and its slate roof was partially missing 1998. The front wall is constructed of squared stone mixing grey limestone and purple Sawdde stone with tooled grey limestone dressings, quoins and voussoirs. Outside steps on the lower gable wall lead to the loft door. All openings except the loft window have stone voussoirs except loft window. The rear wall has two long vent loops to the centre and one to the right. The building was disused and derelict in 1998.

Sources include:
Cadw, Listed Buildings Database

N Vousden, RCAHMW, 21 January 2013