The basic form of the building echoes the layout of the Treasury building. It is a perimeter block building around a central courtyard. A wide hallway runs around most of the building with doorways on either side opening onto rooms that are lit via windows to the courtyard or to the street or garden. The hallway does not continue through the centre of that part of the building located on Stephens Lane. Rooms in this wing are accessed from an arcade on the northeastern edge of the courtyard. Cast-iron balconies also provide circulation around the courtyard. Vertical circulation is provided by fine staircases and lifts associated with the two street entrances. The design also echoes the Treasury building by providing colonnades on the three main elevations.