21 Castle Street

21 Castle Street is an early 19th-century house that was converted into a shop during the mid-19th century. The shop fronts were removed, and the façade was restored in the late 20th century.

The building is constructed of stucco and has a slate roof. It features a dog-leg plan, with a double-pile section facing Castle Street and a longer rear range extending south.

The main façade is three storeys high plus a basement and is divided into three bays. The ground floor has banded stucco, separated from the two upper floors by a plat band, which are smooth rendered. The main entrance is located on the left side and consists of a six-panel door with a decorative fanlight above, set within a round-arched recess supported by moulded brackets. To the right, there are two round-headed window openings, each containing a round-arched timber sash window with glazing bars.

On the first and second floors, there are three timber sash windows in square-headed stucco architraves. The first-floor windows are larger with six-over-six glazing, while the second-floor windows are smaller with three-over-three panes. A plat band runs between the first and second floors, and above the second floor is a projecting cornice topped with a lead-coped parapet. The upper floors also feature eight late 20th-century pattress plates arranged in two rows.

The west elevation of the rear range is blank, while the east elevation includes various timber sash and casement windows on all floors. There is a door at the basement level of the south elevation, a full-height casement window and a smaller two-pane timber sash window on the ground floor, and a tripartite timber sash window on both the first and second floors.

The front range has an M-shaped roof with partially infilled roof valleys, and the rear south range has a hipped roof with a brick chimney stack.