Single Storeyed Building to SE of Octagonal Building at Bersham Ironworks Site.

This is a single-storey building located to the southeast of the octagonal building at the Bersham Ironworks site. It has a roughly eight-sided or near-circular shape, constructed from brick and rubble, topped with a pyramidal roof, although the slates were removed at the time of inspection in July 1995. The roof is supported by pentagonal brick piers at each angle. The northwest, east, and south walls feature what appears to be contemporary brickwork. The south wall includes a relieving arch with later rubble infill below, while the upper part of this elevation is open. There is a similar blocked arched opening in the east wall that once provided access to the adjacent fettling shop. The northwest wall is bowed out in its central section. The west side is open, and the southwest elevation, which is brick above a rubble base, was likely infilled later and has a small ventilation slit. The north elevation has brick infill on a rubble plinth, with a stone sill to the open upper section. The northeast elevation is blind and infilled with brick.

An attached single-storey range has been extensively rebuilt, likely in the late 19th to early 20th century, but it incorporates earlier work between and below the windows on its north elevation. It features five-light windows with concrete sills and lintels. In the east bay, which is probably a later extension, the roof is supported by cast-iron Wilkinson pipes. An A-frame timber truss is exposed in the east gable, and there are lean-to extensions to the south.

Internally, the building is now a single space, but excavation in 1987 revealed traces of internal walls that ran parallel to the external walls, likely removed to facilitate the building's reuse. The roof is braced with a king-post at the intersection of massive cross tie-beams. A cast-iron bracket with a central hole is located at the centre of the underside of the king-post, probably associated with 19th-century agricultural machinery.