The William and Margaret Streets Heritage Precinct is significant as a distinctive residential area defined by modestly scaled interwar and postwar era dwellings, and to a lesser degree, Victorian and Edwardian era dwellings. Most of the dwellings are single storey with detached compositions, featuring hipped and/or gabled roof forms, front or side verandahs, corrugated sheet metal roof cladding, timber weatherboard, face brick and rendered wall finishes, and rudimentary architectural detailing, reflecting the original, predominantly working class population for which they were built. The grid subdivisions between the mid 19th and early 20th centuries were the impetus for building development, although the area was largely transformed during the interwar period into the residential neighborhood identified today. In 1922, the George Street Estate offered 'nine splendid residential sites.' In the 19th century, William Street also known as the location of a quarry used to make bricks. Evidence of this quarry may survive at the rear of the properties between 20 and 26 William Street.
The William and Margaret Streets Heritage Precinct is architecturally significant at a LOCAL level (AHC criterion D.2). It demonstrates original and early design qualities associated with the residential development of the area from the early 20th century until c.1949. These qualities are expressed in the few Edwardian houses and larger number of interwar and postwar Bungalow styled dwellings that are predominantly single storey in appearance with detached compositions. The buildings include the following design characteristics: hipped and gabled roof forms (with simple or complex roof outlines having a pitch between 25 and 35 degrees), front or return verandahs, corrugated galvanised steel roof cladding, horizontal timber weatherboard wall construction, brick chimneys (detailed to reflect the design era), brick cladding and brick verandah supports, narrow or wide eaves, timber verandah posts, timber brackets and/or valances, timber framed doorways with sidelights and highlights and timber windows arranged singularly, in pairs or bays. Overall, these dwellings constitute 78% of the building stock in the area.
The William and Margaret Streets Heritage Area is historically significant at a LOCAL level (AHC criteria A.4, H.1). It is associated with important eras of residential development after the subdivision of the area in the mid 19th century but in particular from after World War 1. It was from 1922 that the area was transformed into the residential neighborhood that largely survives today. It is highly likely that the quarry was used to make bricks from clay at the rear of the properties between 20 to 26 William Street. This provides an interesting contrast to the early housing that eventuated nearby. Mostly these 40 houses from the c. 1860's were rudimentary and small in size. Only one of these houses at 22 William Street survives today.
The William and Margaret Streets Heritage Area is scientifically significant at a LOCAL level (AHC criterion C.2). The area has archaeological research potential given the previous quarry activity in William Street.
Overall, the William and Margaret Streets Heritage Precinct is of LOCAL significance.