22 South William Street, Perth

22 South William Street is an early 19th century, two-storey, three-bay villa featuring a piend roof. The villa has a prominent central entrance with a large pilastered and corniced doorpiece. It is constructed of painted rubble with ashlar dressings and raised margins, and has a moulded eaves cornice. At the rear, there is a full-height bowed stair projection topped with a conical cap. A lean-to porch addition is located at the left re-entrant angle. The property includes a small walled garden at the rear, which adjoins the wall of a railway viaduct embankment.

The villa predominantly features 12-pane glazing in its timber sash and case windows, and is roofed with grey slate. It has tall, coped end stacks with round and octagonal clay cans, and cast-iron rainwater goods. There is also a coped boundary wall adjoining the property to the rear.

Inside, the villa has cast-iron banisters and a timber handrail on the staircase, along with some fire surrounds in the principal rooms. The property is currently undergoing conversion to a twin occupancy residence, which began in 2009.