What made the Bank of London in Buenos Aires an example of Brutalist architecture?

The Bank of London in Buenos Aires (1960–66), designed by Clorindo Testa, Santiago Sánchez Elía, Federico Peralta Ramos, and Alfredo Agostini, is considered a prime example of Brutalist architecture due to its specific structural and aesthetic choices.1

The building exemplifies the Brutalist style through the following features:

• Raw Materiality: The structure utilizes rough, unfinished concrete, a hallmark of the Brutalist movement that emphasizes the honesty of materials.21
• Structural Expression: The design features large-scale concrete piers on the facade, which serve the functional purpose of supporting the building while leaving the interior banking hall free of columns.13
• Complex Geometry: The building is characterized by complex spatial arrangements, including upper office levels that appear to float above the main hall, connected by bridges that link various horizontal planes.1
• Massing: The use of massive, sculptural concrete forms creates a powerful visual presence, aligning with the aesthetic shift toward monumental silhouettes that defined Brutalism in the 1960s.21

By prioritizing these functionalist and structural elements, the bank reflects the core principles of the movement, which sought to emphasize the strength and utility of the building's components.21