4 Wellington Square, Ayr

4 Wellington Square is an earlier 19th-century, two-storey house with a basement and an attic at the rear, forming part of a terrace. The building is constructed of painted ashlar stone and features banded rustication on the basement, a ground floor band course, an eaves course, a cornice, and a blocking course. The windows are architraved, with square brackets at the lower cill corners on the ground floor and cornices above the ground floor windows.

On the south elevation, the entrance has a central stepped platt that oversails the basement. It features a corniced, consoled doorpiece with a later architrave, a two-leaf timber door, and a segmental fanlight. Above, there is a single window aligned with the door at the first floor, and below, a timber door with a letterbox fanlight is aligned at the basement. The flanking bays have regular fenestration at the basement, ground, and first floors.

The windows are predominantly 12-pane timber sash and case, with plate glass, and the roof is covered with grey slate, featuring coped stacks and both circular and square-plan chimney cans.

The interior was not seen in 1998. The property also includes railings and a gate, with ashlar copes topped by spear-headed iron railings, and sections delineated by pineapple finials, with the gate located to the outer right.