Conservatory, Rhuarden, 1 Sutherland Crescent Upper, Helensburgh

Rhuarden is a large, asymmetrical Greek Revival villa dating to circa 1871, designed by William Leiper, with a late 19th-century conservatory also by Leiper. The house is located at 1 Sutherland Crescent Upper, Helensburgh.

The villa is constructed of stugged, snecked cream sandstone with ashlar dressings. A base course, cill course, ashlar pilaster-mullions, pilastered reveals, an architrave, and a frieze above the tripartite window to the south gable, feature patera decoration. Deep, overhanging eaves are supported by brackets.

The south (entrance) elevation has a taller, advanced gabled bay at the centre, flanked by single bay wings. A porch is situated in the re-entrant angle to the right. The porch is advanced gabled with Scamozzi-Ionic columns and a window to the right return. It contains a pair of panelled doors. To the left is an advanced gabled bay featuring a deep, five-light bow window at ground level, and a tripartite window above. A recessed bay to the left has a slightly advanced tripartite window at ground level and an entablature, with a bipartite window above it at the first floor.

The west elevation presents a gable bay to the right, with a window to the left at ground level and a conservatory to the right. Two windows are at the first floor, and an advanced chimney wall is positioned off-centre to the left. A single wing is to the left, with bipartite windows at both ground and first floors. An advanced, lower, two-storey service wing is at the extreme outer left, with a single window at ground level and a bipartite window above.

The north (rear) elevation features a taller central gabled bay. A bipartite stair window is found at the first floor, with single-storey and lower two-storey service wings abutting. The east elevation has a window to the centre at ground level, with flanking bipartite windows. A window is at the centre and a bipartite window to the left at the first floor, and a bipartite window is to the outer right. Windows are primarily plate glass sash and case, with lead-pane glazing. The porch, hall, and stair-hall windows have painted glass. The roof is covered in grey/green slate, and corniced sandstone stacks are present.

The interior is fine, with an encaustic tiled porch and a half-glazed vestibule door. Features include corniced ceilings, a drawing room with a timber chimneypiece flanked by Ionic columns and a timber screen to the bow window, and a dining room with wainscot and a black marble chimneypiece with marble columns. A stone stair has timber balusters. A pantry retains original fittings, and a mezzanine is situated above.

The hexagonal, timber-framed conservatory stands on an ashlar plinth and is joined to the villa by a short, glazed link corridor; a lean-to glazed potting shed extends from the north side. A doorway leads south.

Drum ashlar gate piers with bell-cast caps mark the entrance.