1 Commercial Street, Port William

5 Commercial Street in Port William is an early 19th-century single-storey cottage with a basement, featuring three bays. The building is constructed from rubble, with cherry-caulked sections on the south elevation and projecting granite cills.

On the south elevation facing Commercial Street, there is a central doorway with a panelled door and a fanlight above that includes a letterbox. Steps lead up to a platt, flanked by plain iron handrails. The outer bays at ground level contain windows, while the basement has boarded doors in the outer bays.

The west elevation is attached to No 5 Commercial Street, and the east elevation is connected to the lower building at No 1 Commercial Street. The cottage features 12-pane glazing in sash and case windows, coped skews, and partly rendered rubble stacks that are shared with the west elevation and gable-headed to the east. The roof is covered with graded grey slates and includes two small rooflights on the south pitch. Additionally, there is a rubble wall that shields the basement area at the front of the property.