The AJA facade concept for City North Substation, on the corner of Sussex & Erskine Street, was selected for its bold, simple aesthetic in a limited design competition to clad the building envelope. Using a matrix of aluminium panels and coloured or frosted glass, the facade's Mondrian expression provides an abstract reference to the transmission of energy to the Sydney grid. This also provided an adaptable elevation system that could accommodate the complex facade requirements for louvres and access openings.

On both street frontages provision has been made for the display of static and digital art. Grid Gallery has opened as part of VIVID light festival and is Sydney's first public and web-based gallery space dedicated solely to the exhibition of digital art