21 Segontium Terrace

21 Segontium Terrace is part of a late Georgian terrace consisting of seven three-storey, two-bay houses with basements. The houses feature rendered fronts, while some retain original moulded architraves around the windows and have exposed rubble stone walls at the rear. The slate roofs are sloped towards the back, and each house has a brick or roughcast chimney stack on the right side. The doorways are located on the left sides and are accessed by steps. Many of the houses still have original iron railings on dwarf stone walls, although the gates to the basement steps have been replaced. The railings are adorned with trident finials and urn finials on the stanchions.

The front of the building is roughcast and includes late 19th-century keyed and eared architraves around the original openings, along with a sill band on the middle storey. The windows have all been replaced and are positioned beneath the eaves on the upper storey. The doorway is now within an added flat-roofed porch, and the forecourt railings have been removed.