12 Glenan Gardens, Argyle Street West, Helensburgh

9 Glenan Gardens is a later 19th-century symmetrical terrace consisting of 14 houses, including double villas at each end. The building is constructed from cream snecked sandstone, with cream sandstone ashlar on the northern elevation. It features base, string, and cill courses, as well as a cornice. The full-height tripartite bow windows have banded stone mullions, and throughout the terrace, there are 2-leaf panelled doors with half-glazed vestibule doors.

On the northern elevation facing Argyle Street, houses 7 and 8 are advanced villas at the center, with paired doorways and two windows above on the first floor, flanked by bow windows. House 9 is a recessed 3-bay villa to the right, with a window at the center on the ground floor, a door to the right, and a window to the left, along with three windows on the first floor. Houses 10 to 12 are three villas on the far right, detailed similarly to the others but not advanced. Houses 13 and 14 are an advanced double villa on the outer right, featuring a central door with a window above on the first floor, flanked by bow windows, and a window on the return to the right at the first floor, with a recessed doorway to the outer right. The villas to the left of the center mirror this arrangement.

The side elevations facing William Street and John Street have three windows each at the ground and first floors. Most windows are plate glass sash and case. The roof is covered in grey slate, with canted slate-hung dormers above the bow windows, bipartite windows above the 3-bay villas, and coped sandstone ashlar stacks with original cans, along with original rainwater goods.