4 St Mary's Street

4 St Mary's Street is a terraced town house dating from the 19th century, featuring an unpainted stucco frontage, a modillion eaves cornice, and hornless sash windows. The house has a slate gabled roof with a red brick chimney stack. It is part of an unusual pair of three-storey and basement buildings, with three bays on the upper floors and five bays on the ground floor. The upper floor has hornless sash windows with nine panes, while the main floors have twelve-pane windows. The ground floor includes two doorways aligned with the outer windows of the upper floors, with an additional outer window on each side, creating an alternating pattern of two doors and three windows. The doors have been renewed and are set in open-pedimented arched doorcases with fanlights and radial glazing bars. These doorcases feature pilasters with plinths and console brackets supporting the open pediments. The door to No 4 is half-glazed. The windows are set on stone sills, and there is a basement light beneath the outer windows, which is protected by 20th-century replacement railings.

Since 1981, the doorcase to No 4 has been replaced to match that of No 3, which has undergone significant renewal. The left ground floor room has been altered for use as an office and features panelled shutters. There is a 19th-century staircase behind to the left leading to a room at mezzanine level. A door to the right leads to a room with a reeded ceiling border and a panelled door that connects to the hall of No 3, which retains its original staircase.