27 John Street, Helensburgh

27 John Street in Helensburgh is a three-storey tenement building designed by Robert Wemyss in 1896. It features a near symmetrical three-bay layout, with rake-jointed red sandstone at the ground floor on the east side and harled upper storeys, complemented by ashlar dressings. The building has a base course, a cornice between the ground and first floors, architraved windows, and ashlar mullioned tripartite and Venetian windows. Notable architectural details include chamfered arrises and a corbelled eaves course.

The east elevation facing John Street has a segmental-arched pend located off-centre to the left, with a window to the right. Inside, there is a glazed tiled dado in the close. The outer right and left sides feature Venetian windows, while the centre has a corniced window at the first floor and a pedimented dormer-headed window breaking the eaves above, set within a slightly advanced ashlar panel. The windows have harled aprons, and there is a St Andrew's Cross in the tympanum. A tall corniced wallhead stack is positioned to the right. Full-height canted oriels are located on the outer right and left, supported by heavy console brackets, with mannered quoins at the angles, harled aprons, overhanging bracketed eaves, and a piended slate roof.

The west (rear) elevation features a projecting stair block at the centre, with a window at the first floor that has coloured glass margin glazing, and a segmental-arched window at the second floor, both flanked by narrow windows. To the left, there are two recessed bays with two windows at the ground and first floors, and dormer-headed windows above. To the right, there is a window at the ground and first floors, with a dormer-headed window above.

Most of the windows are plate glass casements with fixed small panes above. The roof is covered in grey slate, with ashlar coped and harled stacks.