21 Castle Street, Duns

19-21 Castle Street in Duns is a mid-19th century, three-storey, three-bay house that features shops on the ground floor, forming part of a stepped terrace. The building is constructed from coursed stugged cream sandstone ashlar with polished dressings. It has a regular arrangement of windows with raised margins, blocked cills, and quoin strips.

On the ground floor, there is an Ionic pilastrade and a dentilled cornice. The central entrance consists of a deep-set panelled door topped with a rectangular plate glass fanlight, flanked by a pair of three-bay shopfronts. Each shopfront includes a deep-set panelled and glazed door alongside plate glass windows. The northern gable is blank and harled. The upper floors are fitted with timber four-pane sash and case windows. The roof is covered with grey slates and features rebuilt brick stacks and ashlar coped skews.