121 Bentinck Drive, Troon

121 Bentinck Drive in Troon is a two-storey T-plan villa, possibly designed by John Rutherford Johnstone around 1910, and later subdivided in the 20th century. The building features an asymmetrical design with elements reminiscent of Charles Voysey. The front has a three-bay layout, with single-storey bays on either side of a two-storey entrance bay. The exterior is finished with whitewashed harl, has overhanging timber bracketed eaves, and is topped with red tile piended roofs. The walls are battered, the angles are boldly buttressed, and there is a columnar entrance. To the north, there is a single-storey L-plan garage block.

On the south (front) elevation, the central columnar porch features a recessed, part-glazed timber panelled door, a six-light fanlight beneath a segmental-arched cornice, and tripartite side-lights. To the right, there is a bipartite window in the reveal, while the upper floor has paired columns that support a projecting two-bay section breaking the eaves above, with bipartite windows in each bay. The outer right bay has a five-light bowed window at ground level, and the outer left bay contains a stylised Venetian window.

The west (side) elevation consists of a four-bay wing with a five-light bowed window in the outer right bay and a tripartite window in the outer left bay. Above these, there are two tripartite windows that break the eaves. There is a recessed wing to the outer left featuring a glazed porch in the re-entrant angle to the right, a single window aligned at the first floor, and two bays with single windows to the outer left, along with a bipartite window at the first floor offset to the right.

The villa predominantly has 12-pane timber casement glazing, with some ground-level windows featuring two-pane upper sections and plate glass lower sections. Various skylights are present, and the roofs are swept red tile piended with replacement rainwater goods. The chimney stacks have crenellated detailing and are topped with whitewashed rectangular-plan ridge and apex stacks, along with circular terracotta cans.

The boundary wall, entrance gateway, and piers consist of red sandstone coping atop a stepped harled wall that encloses the site. There is a round-arched, buttressed entrance arch leading to Bentinck Crescent, with a boarded timber pedestrian entry gate. The entrance from Bentinck Drive is flanked by coped rectangular-plan piers with round-arched caps, although the gates are missing.