[1] The interior, designed by Guy Allbut, originally comprised a demonstration theatre, showroom, offices and staff accommodation.

[1] In 1959, when Shortland County Council became responsible for electricity supply in the Hunter Region, they constructed a three-storey extension at the back of the building.

[3] With the opening of BHP Steelworks in 1915, industrial development stimulated population growth in the area resulting in an increasing demand for power.

By 1937, the Council's Electricity Department "was providing over 87 million kilowatt hours of power and attracting annual revenue of £450,000".

[4] Selected by the delegates, Mayor, Alderman H. Fenton and Electrical Engineer, Guy Allbut, Emil Sodersteen (his name was changed to Sodersten by deed poll in 1941), who in 1927 achieved national prominence by winning the design competition for the Australian War Memorial in Canberra, was chosen as the architect to design the new building.

[2] N.E.S.C.A House marks a new era in the architecture of Sodersten, his disillusionment with the skyscraper leading him to draw on English perspectives and European functional modernism for his future designs.

[2] Construction began in 1937 and, after significant delays due to water on the site and difficulty in obtaining the correct steel sections, the building was opened on 8 September 1938 by Hon.

[9] N.E.S.C.A House was designed, by Emil Sodersten, on contemporary English lines in keeping with the work of Wells Coates and George Coles.

[2] NESCA House is of state significance as an outstanding Art Deco building by the architect Emil Sodersten.

[2] Nesca House was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.

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

NESCA House is of State significance as an outstanding example of Art Deco style with tendency towards Functional Modernism.