109, Castle Street

No. 109 Castle Street is a house from the early 19th century. It features a combination of brick, rendered surfaces with sponge decoration, and timber framing that is plastered. The roofs are made of slate and peg tiles, and there is a brick chimney stack. The building has an L-shaped plan that rounds the street corner with Little Walden Road, with a partial infill of the internal angle by a single-storey lean-to.

The house has two storeys. The south front elevation has two windows and a central front door. All windows are 19th-century horned sashes now fitted with diamond leaded glazing. The doorway is wooden and features a flat cornice hood, a fluted frieze, and jambs that are bead moulded with simple projecting panel decoration. The door itself has four recessed panels. The roof is hipped around the eastern end corner.

On the eastern elevation, facing Little Walden Road, there is a block of a single window range similar to the south front. To the north, there is a lower two-storey timber-framed and plastered wing. This wing has one window range, and its peg-tiled roof has a steep pitch. The ground floor features a single casement window with lattice glazing and an adjacent simple boarded door. The first floor has a sliding sash window with two by two panes, also lattice glazed.

On the rear western elevation, the Castle Street range has a single-storey 20th-century pantiled lean-to that leads into a small courtyard, along with a short two-storey lean-to that has a 20th-century light casement window with two by two panes. The timber-framed wing has a first-floor 20th-century single-light casement window, while the ground floor is obscured.