66 Constitution Street, Edinburgh

68 and 70 Constitution Street is an early 19th century tenement that received an attic storey addition by James Simpson in 1878. This four-storey building features an attic and has a symmetrical seven-bay layout, with a central pend and a basement. The front is made of cream sandstone with tooled ashlar and polished dressings, while the rear is constructed from coursed rubble with droved dressings. The basement has a rock-faced finish, the ground floor is rusticated, and there are various decorative features including a band cill course at the second floor and a projecting cill course at the third floor. The eaves cornice and blocking course are also notable, along with iron window guards on the third-floor window to the right.

The east (front) elevation has a segmental-arched pend, which has been partially glazed. On the first floor, there is a segmental-arched recess with a tripartite window featuring acanthus leaf capitals and a pulvinated frieze with a blank panel. The second floor has another tripartite window, while the third floor has a single window above. The slightly advanced bays on either side of the centre contain pilastered doorpieces accessed by raised steps. The left side has paired doorways with panelled doors and a segmental-arched fanlight, while the right side features a tripartite segmental-arched doorpiece with a two-leaf panelled door and sidelights with etched glass. The first floor has an architraved and corniced window, with single windows on the second and third floors above. The outer bays also have single windows. The mansard roof includes crude gabled dormers, with three single dormers in the centre flanked by canted dormers.

The north and south elevations are blank gables with apex stacks that have been rebuilt. The west (rear) elevation features a bowed bay on the outer right with single windows, and the remaining bays also have single windows.

The building has timber sash and case windows, primarily with plate glass glazing, along with some four- and eight-pane windows at the rear. The roof is slate, with two apex chimney stacks.

The interior was not seen in 1993. The property includes low boundary walls with curved coping, iron gatepiers flanking the pend, and elaborate original iron gates and railings.