10 Northumberland Street, Edinburgh

12 Northumberland Street in Edinburgh is an early 19th-century, three-storey and basement terraced tenement designed by Robert Reid and William Sibbald. It features a polished ashlar sandstone façade with V-jointed rustication at the principal floor. The building has a base course, band courses between the basement and principal floor, as well as between the principal floor and the first floor. At the first floor of No 12, the cills are lowered for the windows, while projecting cills are present in the bays at the second floor. The structure is topped with a cornice and blocking course at the second floor. The windows are architraved with cornices at the first floor, and there are smaller windows on the second floor. Ashlar steps and entrance platts extend over the basement.

On the north (principal) elevation, there are recessed doorpieces in the third, fourth, seventh, and tenth bays from the left, featuring six-panel timber doors with radial rectangular fanlights. The remaining bays have regular fenestration at the principal floor and on the upper floors and basement. The first floor bays at No 12 have fluted aprons.

The east elevation is part of an adjoining terrace, which is listed separately (16 and 18 Nelson Street). The west elevation consists of coursed rubble and is predominantly blank, with a window centered at the second floor.

The building predominantly has 12-pane timber sash and case windows, with window guards in the bays at the first floor of Nos 6 and 8, and spanning the bays at the first floor of No 10. The roof is covered with grey slate and features cast-iron rainwater goods, along with rubble and rendered ridge stacks and a rubble gablehead stack, which is coped and has circular cans.

The interiors were not seen in 1997, but there is some evidence of working panelled shutters. The property is also adorned with ashlar copes topped by cast-iron railings that have spear-headed balusters and pineapple finials, along with cast-iron lamps mounted on the railings featuring glass globes.