Overmonnow House, including attached railings

Overmonnow House is a three-storey building, likely dating from the 18th century, with a stucco exterior that is painted and possibly applied over local rubblestone. It features painted dressings and a plain tile roof, along with a modillion eaves cornice and smooth stucco surfaces. The main street facade has five windows arranged in pairs on either side of a central bay, which includes a central doorway. The doorcase is topped with a broken pediment supported by brackets and features a radiating fanlight above a six-panel door with panelled reveals. The ground and first floors have 6 over 6 pane late 18th-century type sash windows, except for the central first-floor window, which has a semi-circular head with a stucco surround, key, and impost blocks, and a 6 + 6 pane casement with an ogee tracery fanlight. The top floor is fitted with 3 over 6 sashes. The roof slopes gently with a slight bell cast, and there are tall rendered stacks on each gable. The property is enclosed by attached spearhead wrought iron railings and a gate.

The return wall on the right side is partially covered by a lean-to on the ground floor and has a small window on the second floor at the rear. The left return wall features a sash window on the ground floor. The garden elevation includes a central full-height gabled stair wing, which is extended on the ground floor by a conservatory added around the 1990s. Above this, there is a tall arched stair window with a 6 over 12 pane sash. To the left, a modern lean-to covers the ground floor, with a 6 over 6 pane sash above. To the right, there is a French door flanked by a 6 over 6 pane sash window with half panes above and a small eaves window.

Internally, the layout consists of a basic four-room plan surrounding a wide central hall, with an open well stair leading to the attic in the rear wing. There is one bolection moulded door surround that may date from the early 18th century and an 18th-century panelled room, though most of the joinery is from early 19th-century alterations. The stair features an unusually wide well, closed string, turned balusters, and a moulded handrail. The attic landing shows signs of an undatable alteration, with balusters of a different pattern supporting a three-bay arcade of unusual design.