M506, the Cocktail Bar, is a significant part of the Commonwealth Parliamentary Refreshment Rooms of Provisional Parliament House and was an integral part of the building’s early design and development. Located in the South wing of the building, the various separate dining and bar facilities of the rooms reflect the stratification of various classes of occupants of the building, especially in its early life when women, kitchen and waiting staff, and senior officers such as the Clerks of the House of Representatives and the Senate, all had separate dining rooms. The range of facilities was also vital if the building was to be fully self-contained as originally intended.

Like much of Provisional Parliament House, room M503 was designed by the Commonwealth’s first government architect, John Smith Murdoch, and though somewhat altered it still displays the form, massing and style of the Inter War Stripped Classical style of the 1927 building. The rooms tend to be simple spaces with understated decoration. Subtle and repeated classical references, such as the use of Greek decorative elements and patterning, are found in these interiors.

M506 is of significance in the history of the Old Parliament House building for its role as the bar and recreation place for Parliamentary staff. Room M506 was initially utilised as a servery (a room used for the preparation and serving of food other than a kitchen), however in 1948 was converted to a cocktail bar. By 1983 the bar had been refurbished but still retains the simple and dignified appearance that Murdoch intended. Room changes have been common in Provisional Parliament House and reflect its changing nature since opening in 1927.