15 The Square, Port William

15 The Square in Port William is a house built in the later 19th century. It is two stories high with an attic and has three bays, featuring a shop on the ground floor. This building is paired with Nos 5, 7, and 9 The Square.

On the north elevation facing The Square, there is a central door with a two-pane fanlight above it. To the left is a shop front that includes a central door flanked by windows. There is a window in the bay to the right on the ground floor, and the first floor has regular fenestration. Above the outer bays, there are flat-roofed three-light dormer windows.

The east elevation is adjoined to Nos 17 and 19 The Square.

On the west elevation, there are paired 12-pane sash and case windows on both the ground and first floors. The ground floor features plate glass display windows. The building has red sandstone coped skews that are shared with the east side. There are rubble stacks, with a gablehead to the west that is also mutual to the east. The roof is covered with purple slates and has octagonal cans.