17 Segontium Terrace, including forecourt railings

17 Segontium Terrace is a late Georgian terrace consisting of nine three-storey, two-bay houses. The buildings feature slate roofs and brick or roughcast stacks on the right side. The entrances are located in the left-hand bay and are accessed by steps. In front of the houses, there are original iron railings on dwarf walls, which have pointed finials and cone finials on the stanchions, although the gates have been replaced.

Houses numbered 15-19 have a larger footprint than those numbered 11-14 and project forward at the rear. They also retain original architraves on the front elevation, while houses 11-14 display late 19th-century details. The terrace has a roughcast front with a moulded eaves cornice. The doorway, which is in a recently added porch, features an original moulded architrave, a replaced door, and an overlight.

The windows are set in original moulded architraves, with keystones in the lower and middle storeys and sill bands on the middle and upper storeys. The lower and middle storeys have six-over-single-pane sash windows, which include coloured glass, while the upper storey has three-over-single-pane sash windows. Additionally, the basement retains a two-pane sash window. This terrace is part of a group that includes houses numbered 11-19 Segontium Terrace.