The decoration was carried out by João Vicente Friedrichs' workshop, with the participation of Jesús Maria Corona, Franz Radermacher, Wenzel Folberger and Victorio Livi.

[1][4] The building adopts an eclectic style with a strong German Baroque influence, and has a dynamic facade with a prominent portico, a large clock tower on the left and metal domes at the corners.

It also features profuse ornamentation in floral and abstract patterns, and some sculptures, including the Atlas group above the pediment, flanked by images representing Europe and America.

The 3,500m² of facades received special treatment; internally, the areas destined for the Historical Archives of Rio Grande do Sul and the Treasury Rooms were equipped with air conditioning.

The internal courtyards received skylights and elevators to allow for greater integration with the other areas, and the terrace was freed from later unnecessary additions.