A Grand Palace

The Customs House was built to be one of Melbourne's grand buildings. Its grandeur declared that Melbourne was a thriving and wealthy metropolis, linked by trade to Britain and the other major cities of the British Empire.

Customs was the treasure house of government income. Until the introduction of income tax in 1915, customs duties raised some four-fifths of all government revenue.

The architecture was based on an Italian Renaissance palace. In the Palazzo style, the ground floor is a storage area, and the main activity occurs on the piano nobile (noble level) on the first floor.

Architect Peter Kerr modelled the ionic columns and door architraves on details of the Erechtheion temple in Athens. The plaster decorations may have been manufactured locally by British and Italian modellers, who established a local industry in the 1850s.