9 Castle Street

9 Castle Street is a house dating from the mid- to late-18th century, later used as a shop in the 19th century and as offices in the 20th century, with the shop fronts subsequently removed. The building is constructed of silver-grey brick in a header bond, with red brick detailing, and has a slate roof. Later 20th-century extensions are in red brick.

The building has an L-shaped plan, with a main north-facing range fronting onto Castle Street and a longer rear extension to the west. The principal north elevation is three storeys high over a basement, with three bays and a coped parapet. A central doorway is accessed by two stone steps and features a six-panel door with a radiating fanlight above, flanked by Doric pilasters rising to fluted brackets supporting an open pediment.

The outer bays on the ground, first, and second floors have matching canted oriel windows with flat, lead roofs, each containing a larger, central sash window with six-over-six panes to the ground and first floors and three-over-six panes to the second floor. Narrower sash windows are located to the sides of the oriels. Segmental relieving arches in red brick are positioned above each oriel. The oriels spring from coved brackets, which cross the relieving arches of the ground and first floor oriels. Red brick detailing runs between the two bays of oriels, rising from the ground-floor plinth to the top of the parapet. Further detailing is present on either side of the doorway, and red brick quoins define the ends of the elevation. A 20th-century basement window, protected by modern railings, is set beneath the eastern ground-floor window, beneath a soldier course of red bricks.

The roof is complex, with three transverse pitches connected by hipped elements in the valleys, and a dormer projecting north into the central valley. A lead-covered dome rises through the southern slope of the central pitched roof.

The largely hidden south elevation includes a three-storey projection running along the western side, with a window at second-floor level, followed by a two-storey extension running south under a pitched, plain-tile roof.

The interior is understood to contain an 18th-century staircase connecting the first and second floors.