Brutalist buildings are usually formed with repeated modular elements forming masses representing specific functional zones, distinctly articulated and grouped together into a unified whole. Concrete is used for its raw and unpretentious honesty, contrasting dramatically with the highly refined and ornamented buildings constructed in the elite Beaux-Arts style. Surfaces of cast concrete are made to reveal the basic nature of its construction, revealing the texture of the wooden planks used for the in-situ casting forms. Brutalist building materials also include brick, glass, steel, rough-hewn stone, and gabions. Conversely, not all buildings exhibiting an exposed concrete exterior can be considered Brutalist, and may belong to one of a range of architectural styles including Constructivism, International Style, Expressionism, Postmodernism, and Deconstructivism.
Another common theme in Brutalist designs is the exposure of the building's functions—ranging from their structure and services to their human use—in the exterior of the building. In the Boston City Hall, designed in 1962, the strikingly different and projected portions of the building indicate the special nature of the rooms behind those walls, such as the mayor's office or the city council chambers. From another perspective, the design of the Hunstanton School included placing the facility's water tank, normally a hidden service feature, in a prominent, visible tower.
Brutalism as an architectural philosophy was often also associated with a socialist utopian ideology, which tended to be supported by its designers, especially Alison and Peter Smithson, near the height of the style. This style had a strong position in the architecture of European communist countries from the mid-1960s to the late 1980s (Bulgaria, Czechoslovakia, GDR, USSR, Yugoslavia). In Czechoslovakia brutalism was presented as an attempt to create a "national" but also "modern socialist" architectonic style.