41 Castle Street, Duns

41 Castle Street in Duns is an early 19th-century, two-storey and attic, three-bay end-of-terrace house that likely incorporates older materials. The building is constructed of harled rubble sandstone with ashlar margins and features regular fenestration. At the center, there is a flat-panelled door topped by a 5-pane letterbox fanlight. To the left, there is a piend-roofed dormer, and to the right, a Velux skylight is present.

The south gable end has two bays, with a blank section to the right at ground level. The rear elevation is irregular. The house has 12-pane timber sash and case windows, brick chimney stacks, grey slate roofing, and ashlar coped skews.