149 Clyde Street East, Helensburgh

3 Glenfinlas Street in Helensburgh is a late 19th-century, three-storey tenement located at the corner of Clyde Street East and Glenfinlas Street. The building is constructed from cream squared and coursed sandstone, featuring horizontal banding on the first floor. It has a base course, raised margins around the windows, and a wide ovolo-moulded frieze with a cornice between the ground and first floors. Decorative patera can be found between the string course and cill course on the second floor, topped with a cornice.

On the south elevation facing Clyde Street East, there are two widely spaced bipartite windows at the center of the ground floor, with a doorway to the right and a window at the far right. To the left of the doorway, there are windows flanking it, and a bipartite window on the outer left. The center features two full-height canted oriel windows, with additional windows flanking and at the far right and left. The outer left also has full-height canted oriels, while the corner of Clyde Street and Glenfinlas Street is marked by full-height bow windows.

The east elevation facing Glenfinlas Street has two bipartite windows at the center of the ground floor, with flanking windows and a doorway at the far left. Another doorway with flanking windows is located at the far right, along with a bipartite window on the outer right. The center again features two full-height canted oriel windows, with additional windows flanking and at the far right and left, and a full-height canted oriel window on the outer right.

Inside, there is a stone dog-leg staircase leading to the pends, adorned with an iron balustrade and stained glass stair windows. The building primarily features plate glass sash and case windows, a grey slate roof, and corniced sandstone stacks with moulded cans.