19 Gayfield Square, 18A, 18, Edinburgh

20 and 20A Gayfield Square is a classical terraced double tenement block designed by Hugh Cairncross in 1808. This building features a symmetrical, four-storey and basement structure with a seven-bay elevation facing Gayfield Square and a six-bay elevation at the rear. The exterior is constructed of droved ashlar, with coursed rubble and droved margins at the basement and dressed margins at the rear. It includes dividing bands between the basement and ground floor, the ground and first floor, and between the second and third floors, along with an eaves cornice and a blocking course. The fenestration is regular throughout.

On the principal southeast elevation, the central bay has steps and a platt that lead to a timber-panelled door topped by a four-light rectangular fanlight. The second and sixth bays also feature steps and a platt leading to timber-panelled doors with half-wheel design glazing above the letterbox fanlight.

The windows are fitted with 12-pane glazing in timber sash and case style. The pitched roof is covered with grey slates and has stone skews and skewputts. There are three chimney stacks: one on the front pitch at the center, and two ridge stacks, one at the center and one to the right. All stacks are corniced in ashlar with droved dressings and circular cans.

The property is bordered by spear-head and urn finialled cast-iron railings set in stone copes that edge the basement recess, along with plain railings that edge the steps and platts.