Barn to South West of Powdermill Farmhouse

This is a barn dating to the late 17th or 18th century, with a later 18th-century powder magazine inserted within it, and further remodelling and re-roofing occurring in the 19th century. Constructed from roughly-squared limestone rubble, it has a brick gable stack and a pantile roof. The building's plan is rectangular, featuring an inserted vaulted powder store at the north end.

The barn's exterior includes a central cart entrance with a timber lintel and double plank doors. To the right of the entrance is a round-arched doorway leading to the powder store, now fitted with a 20th-century glazed door, and a small window to the left. A blocked entrance is located in the south end, positioned beneath an upper segmental-arched door accessing a hayloft. The north gable has a round-arched doorway beneath a projecting 19th-century arch that supports a brick stack. The front and back elevations display irregular toothed ends and a string at eaves height, reflecting the position of a former lean-to. The rear elevation incorporates a small window to the powder store and three blocked lights, alongside a segmental-arched doorway to the right.

Inside the barn, there is a central threshing floor supported by six 19th-century king post trusses, with mid to later 19th-century joist holes cut across the entrance. The south end of the barn contains a chamber, lower than the surrounding walls, characterized by thick rubble walls and a semi-circular groin vault. The barn walls above the chamber are plastered.

The barn is linked to the history of the Littleton gunpowder mill, which operated from the early 18th century. This mill, one of several in Somerset initially designed to supply local mining interests and export through Bristol, ceased operation by the mid-19th century. The complex, including the canal, is now a Scheduled Ancient Monument. The vaulted structure was likely incorporated into the barn during the early stages of mill operations, serving as storage for gunpowder, a critical part of the manufacturing process. Its proximity to the farmhouse, its design, with three openings, and the unique construction within a pre-existing farm building, make it a comparatively unique structure within the context of gunpowder works.