Room M503, or the former Officers’ Dining room, 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 and room M503 still retains the simple and dignified appearance that Murdoch intended.

Room M503 was initially part of the terrace and utilised as a tea room. In 1948 the terrace was enclosed, incorporated into the dining room and converted to the billiard room. By 1983, room M503 had been refurbished and reconfigured as a special dining room. On the main floor, 1983 plans indicate minor changes to create a committee room no 3 (M501), special dining rooms 1, 2, and 3 (M503), and 5 new rooms at the south end of the billiard room (M529). The changes which were undertaken in room M503 are not uncommon for rooms in the building and reflect its changing nature since it’s opening in 1927.