51 Castle Street

51 Castle Street is a house built between 1800 and 1830, with the ground floor originally used for commercial purposes and later converted to office use by the mid-20th century. The building is constructed of red brick in Flemish bond, featuring a rendered ground floor and a slate roof.

The structure has a rectangular footprint extending southeast from Castle Street and consists of three storeys plus a basement, arranged across two bays facing Castle Street, topped with a pitched roof. The western bay of the rendered and painted ground floor includes a six-panelled door with a rectangular fanlight above and reeded casings. Adjacent to the west is a tall, twelve-pane fixed window with wooden glazing bars and matching reeded casing. The eastern bay of the ground floor features an eight-over-eight sash window.

On the first and second floors, there are two eight-over-eight sash windows on each level, all under gauged-brickwork heads, and a stone-coped parapet that conceals the pitched roof. A chimney is located on the eastern half of the roof ridge. At the rear elevation, the basement is rendered and painted white. There is a single-storey brick extension with a hipped roof along the western boundary of the property. The eastern bay of the rear elevation has a column of three eight-over-eight sash windows, while the western bay contains two sash windows positioned between the ground and first floors and the first and second floors; the lower window is an eight-over-eight sash, and the upper window is a six-over-six sash.