5A William Streeet, Helensburgh

7 William Street in Helensburgh is an earlier 19th century single-storey and attic villa with three symmetrical bays and classical details. It is flanked by two-storey, two-bay blocks built in 1900.

The central villa, known as No 5a, features a rendered exterior lined to resemble ashlar with ashlar dressings. It has base and eaves courses, a cornice, a blocking course, and quoin-strips.

On the east elevation facing William Street, there is a timber doorway with an aediculated design at the centre, featuring moulded ashlar ingoes, a panelled door, and a plate glass fanlight, along with a modern glazed vestibule door. The flanking windows have raised ashlar margins, aprons, a dentilled cornice, and a round-headed recessed panel above with a patera at the centre and a blocked keystone. A broad ashlar dormer with an open pediment and pilaster-quoins sits at the centre, featuring an ogee-headed window with fleur-de-lis decoration at the apex. There are later timber bipartite slate-hung dormers on either side.

The ground floor has replacement uPVC windows, while the attic features border glazed sash and case windows. The roof is covered in grey slate, with corniced ashlar end stacks and original rainwater goods.

Nos. 5 and 7 are constructed from stugged snecked cream sandstone with ashlar dressing. They have stop-chamfered arrises, a cill course at the first floor, and timber bracketed eaves with ashlar brackets at the angles.

No 5, the villa on the left, has a corniced doorpiece on the east elevation with a panelled door and a small pane fanlight, along with a half-glazed vestibule door. There is a window to the left and regular fenestration on the first floor, featuring plate glass sash and case windows and a piended grey slate roof.

No 7, the villa on the right, has three bays on the east elevation, with a pend entrance on the outer left that features raised margins, stop-chamfered arrises, and ogee-moulding on the lintel. There is a window to the right and another at the far right, with two windows on the first floor. The ground floor has modern aluminium windows, while the first floor has border glazed sash and case windows. The roof is also piended grey slate, with a corniced ashlar stack above the eaves at the centre of the east elevation, a rendered end stack to the right, and polygonal moulded cans.