Former servant's quarters to rear of Plas Tan-y-bwlch

The building is a former servant’s quarters, located in the rear yard behind Plas Tan-y-bwlch. Dating to the 18th century, it is set at a slight angle to the entrance gatehouse. The principal block is a three-storey structure with a five-window front, constructed of coursed local stone. It features an embattled parapet and a shaped dripcourse running around the upper storey and across the front elevation above the first-floor windows. The roof has a shallow pitch covered in slate, with stone copings and rectangular gable stacks. A doorway is located offset to the right, with a shallow overlight containing glazing bars. Another doorway is situated at the far left, and a partially blocked doorway is found to the right, at the left end, with a window positioned above it. The windows are timber casements, each having two lights.

A later, late 19th-century gabled, two-storey, six-window range is slightly recessed from the right end, and abuts the northwest corner of the gatehouse. A modern doorway is at the left end of this range, and it has four-pane casement windows with slate sills. Connected to the left end of the three-storey block is a modern single-storey wing, faced with stone and having a shallow slate gable roof. This wing has a modern door and windows along its length.