Pyrmont Post Office is linked with the original post office established in 1852, and as such is associated with the early development of the Pyrmont/Ultimo area. Pyrmont Post Office is historically significant because it is associated with the population growth in the area during the late nineteenth century, which was the result of its development as a key industrial and warehouse suburb in Sydney. The Post Office was also an important part of the consolidation of communications services to the Pyrmont/Ultimo community. The building has a history of continuous original use that spans almost a century. The unusual architectural footprint of the building reflects the difficulty with designing and constructing new buildings in already well-established suburbs in Sydney. Pyrmont Post Office also provides evidence of the development of workers' conditions in NSW, particularly with regard to the level of self-containment of the residence.
