This late 1880s St Kilda Road mansion with its distinctive tower and l-shaped verandahs and balconies has both historical and architectural significance within the state of Victoria. Its importance may be summarised as follows:
(1) It has historical importance as a fine, substantially intact example of the many mansions set in spacious grounds constructed on the prestigious St Kilda road, (originally one of Melbourne's grandest boulevards) during the last century. "Ulimaroa" is one of a very small number of survivors.
(2) In addition, "Ulimaroa" is notable for its associations with its first occupier, John Traill (1826-1918), pioneer shipping merchant and director of the well-known Huddart Parker line. The Traill family lived at "Ulimaroa" from 1890 to 1946.
(3) "Ulimaroa" has significance because of its fine architectural detailing, which is attributed on stylistic grounds to the architect JAB Koch.