11 and 13 Union Street, Edinburgh

11 and 13 Union Street in Edinburgh is a classical tenement block built in 1806, likely designed by Hugh Cairncross and constructed by John Aitchison. The building features three storeys, an attic, and a basement, with a near-symmetrical six-bay elevation facing Union Street. The ground floor is characterized by smooth V-jointed rustication, while the upper floors and basement are finished in droved ashlar. The rear of the building is made from random rubble with dressed margins. There are dividing bands between the basement and ground floor, as well as between the ground and first floor, along with a cill course at the first floor and a mutuled eaves cornice.

The principal elevation includes a central bay with a rusticated section, featuring a platt that arches over a basement recess leading to a timber-panelled door set in a round-arched opening, complete with a segmental fanlight. The doorpiece has recessed vertical panels with guttae detail. On the outer left bay, there is a stone step and a platt leading to another timber-panelled and glazed door, which is topped by a five-light rectangular fanlight. The roof is adorned with two tripartite dormer windows.

The building has stone copes at the edge of the basement recess and platts, which are topped with spear-head finialled cast iron railings. A random rubble boundary wall with flat stone coping is located at the rear.

Most windows feature 12-pane glazing in timber sash and case designs, with 4-pane glazing in the outer lights of the tripartite dormers. The dormers have timber fascias and grey slate haffits and piend roofs. There are two rooflights between the dormers and three to the left. The pitched roof is covered with graded grey slates and features stone skews. The building has several corniced stacks, including one rendered mutual ridge stack to the right, one droved ashlar mutual ridge stack to the left, one corniced droved ashlar stack on the front pitch to the left, and one corniced rubble wallhead stack at the rear, all with circular cans.