The front door opened directly into the ground floor room and the staircase was located along the back wall.

It was a characteristic of The Rocks that the lower-standard accommodation was in the back lanes, with a higher quality of house fronting the streets.

Hart, a builder and contractor, had served as the Alderman for the Gipps Ward of the Council of the City of Sydney from 1883 until 1899.

[1] Following the outbreak of bubonic plague in December 1900, an extensive cleansing of the perceived slum areas was undertaken and the entire area from Millers Point, where the outbreak occurred, as far south as Charlotte Place (Grosvenor Street) was resumed by the state, under the Public Works Act.

[1] Drawings for a building on the corner site were prepared by the Government Architect's Branch under the jurisdiction of George McRae, dated 28 February 1909 and designated as a "Factory and Dwelling".

The factory was designed with the health of the workers in mind, providing natural light, fireproof construction and a staff dining room.

This seems to result from its confusion with another building in The Rocks built to house the Resumed Properties section of the Department of Public Works which was located at No.

In 1997 builder, R. E. Charles Constructions Pty Ltd was engaged to undertake repair and maintenance works at 120 Gloucester St which amounted to $26,359.

In 2005 a revised development application was lodged by HEG Holdings Pty Ltd which was prepared by architects, Noosphere Ideas Pty Ltd. whilst combining the buildings at 120 Gloucester and 117–119 Harrington Streets, the revised proposal deleted the already approved new top floor to 117–119 Harrington Street and substituted a two-storey, lightweight penthouse of unambiguously modern design.

[3] Style: Federation Arts and Crafts; Storeys: 3;Facade: red-brown face brick laid in English bond;Internal walls: load-bearing masonry walls;Roof cladding: membrane with a protective layer of pebbles;Floor frame: timber.

[1] The façades are substantially intact with regard to expressing the original 1911 form of the building including the external brickwork, roughcast render, timber window and door frames, the suspended awning over the Gloucester Street shopfront and the dramatically curved parapet around the flat roof.

[4][1] The Model Factory and Workers Dwelling at 120 Gloucester Street, The Rocks and site is of State heritage significance for its historical, aesthetic and scientific cultural values.

This design shows the NSW Government Architect's long-standing interest in workers' housing and the improvement of the urban environment.

The scale, form, use of materials and detailing of the building makes a positive contribution to the intact 19th and early 20th century streetscapes of the Gloucester, Harrington, and Essex Street precinct.

[1] 120 Gloucester Street, The Rocks has a high level of aesthetic significance as an early example of a Federation Free Style factory.

The recorded drawings and photographs of the substandard buildings in Frog Hollow and their demolition provide an insight into the slum dwellings owned by city aldermen that were concealed in the back lanes.

The building is associated with the senior designers of the Government Architect's Branch of the NSW Department of Public Works: Edward Drew and George McRae.

[4][1] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

The scale, form, use of materials and detailing of the building makes a positive contribution to the intact 19th and early 20th century streetscapes of the Gloucester, Harrington, and Essex Street precinct.

[4][1] The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales.

The building is a rare example in the New South Wales context of a model factory and dwelling constructed by the NSW State Government.

[4][1] This Wikipedia article was originally based on Housing Board Building, entry number 1552 in the New South Wales State Heritage Register published by the State of New South Wales (Department of Planning and Environment) 2018 under CC-BY 4.0 licence, accessed on 14 October 2018.