66 St Andrew Street, Castle Douglas

66 St Andrew Street in Castle Douglas is an early 19th-century house that was raised to two storeys and extended in the later 19th century. It is a two-storey attic and basement, three-bay house with a two-bay pavilion. The exterior is constructed of random whinstone rubble with red ashlar sandstone dressings, featuring a lintel course above the basement windows, an eaves course, and quoin strips. The main entrance has a pilastered and corniced doorpiece with a fielded frieze, accessed by a flight of stone steps with railings. The door is decorative, panelled, and part-glazed, complete with a letterbox fanlight. The windows are regularly spaced, with three-pane windows in the basement that open onto the pavement. The building has ball-finialled skewblocks.

The later 19th-century pavilion has a pitched roof and is lower than the ground floor of the main house, featuring slightly smaller windows. The timber sash and case windows have a 12-pane glazing pattern. The roof is covered with graded grey slate and includes a cast-iron rooflight. The skews are ashlar coped, and there are stone gablehead stacks with thackstanes and clay cans. The interior was not seen in 2003.