Mandra Bella is of local architectural and historical significance.
Historically, the property is a remnant of one of the larger semi-rural subdivisions predating 20th century suburban subdivision of Heidelberg. In this regard the orientation of the house away from Carlsberg Road and the numerous surviving outbuildings are of interest. The house is largely intact, and is enhanced by its mature landscaped setting.
Of local historical interest is the connection with various members of the MrCormick family, including William McCormick, station master for 40 years at Flinders Street Station during the late 19th and early 20th centuries, and Renee McCormick, a prominent female member of the architectural profession during the 1940s, 50s and 60s.
Mandra Bella is a single-storey residence of brick construction with a hipped roof, designed in a conservative simple Italianate style. Constructed on a large block, the house faces away from the street and to the east. Walls are of red brick, with a brown brick string course and brown brick voussoirs to the window openings. The east elevation has a verandah supported on timber posts and simple slatted timber balustrading; the frieze appears to have been removed. A small gable in the verandah roof marks the entrance. The entrance is asymmetrically located-which may indicate an extension to the north-and has a leadlight glazed upper panel and sidelights. Both the verandah roof and the main hipped roof have been recently re-clad in corrugated galvanised steel. Windows on the east elevation are timber-framed double-hung sashes, and extend to the floor. The tall red brick chimneys have corbelled brick caps and terracotta pots.
A timber wing has been added at the north-west corner, dating from the late 1920s. An early timber wash house with a timber trough and a workshop building exists along the west boundary. These outbuildings do not appear on the 1926 plan, but must have been built soon after. To the north is a small gabled building with an ornamental finial and lattice vent under the eaves, which may be the former stables.
The large block is a remnant of the original two acres, and slopes down to the north. Remnant cypress hedges and woven wire fencing appear date from the 1920s, during McCormick's ownership of the property. North-west of the stable are two large Monterey pines which appear to be contemporary with the house.
In the 1880s, the prospect of rail transport, promised first to Alphington, and then to Heidelberg, provided the impetus for land speculators and developers in the area and saw the district's fortunes appear to take a turn for the better. These estates were marketed as high quality residential subdivisions. In suburbs such as Ivanhoe and Heidelberg, however, much of this land remained unsold, and relatively few houses were actually constructed following the land sales of the 1880s. Mandra Bella is one of a small group of residences erected in the late 19th century for Melbourne 'gentlemen' seeking refuge from the city.