19, St Mary Street

19 St Mary Street is a house dating from the early 18th century, with an early 19th-century rear wing. It is constructed from limestone ashlar with a rubblestone plinth, and rubblestone at the rear. The stone slate mansard roof is hipped to the left, featuring ashlar stacks at the rear, while the stack for the rear wing is made of brick with a moulded ashlar shaft. The house has a central stair-hall plan with a rear right wing.

The exterior consists of two storeys with an attic and basement, presenting a symmetrical five-window arrangement. It features a fine moulded cornice, a high parapet with moulded coping, a ground-floor lintel string course, and chamfered rusticated quoins. The 18th-century six-over-six pane sash windows have painted moulded architraves and thick glazing bars. The central bay is slightly stepped forward and has pediments above the cornice and lintel string, which is supported by brackets over the entrance. Steps lead up to a six-panel door with raised and fielded panels, accompanied by a margin-paned overlight and moulded architrave. To the right, there is a plain stone mullion for a two-light basement window, and a cyma-moulded mullion for a two-light window in the gable of the left return. The rear features two hipped dormers and two six-over-six pane sash windows with moulded architraves. The early 19th-century rear wing has timber lintels above the openings, a roll-edge moulding on a margin-paned sash window, and a hood on brackets over a central door.

Inside, the hall is adorned with a modillion cornice and has an open-well, open-string staircase featuring a fluted column newel, a swept handrail, and a corresponding dado. The ground-floor rooms are fitted with box cornices. A semicircular arch leads over a straight flight of stone steps behind the left-hand room, descending to a barrel-vaulted, stone-flagged cellar beneath the main building. The three-bay roof has tenoned purlins and a ridge in notch. The rear wing contains three cross-beams and a brick breast for an open fire. The facade is similar in design to No. 61 St Mary Street, which is likely from 1702.