The Tricorn Centre, Portsmouth

Brutalist architecture is a movement in architecture that flourished from the 1950s to the mid-1970s, descending from the modernist architectural movement of the early 20th century. The term does not derive from the word "brutal," but originates from the French béton brut, or "raw concrete," a term used by Le Corbusier to describe his choice of material.  British architectural critic Reyner Banham adapted the term into "brutalism" (originally "New Brutalism") to identify the emerging style.

Brutalism became popular with governmental and institutional clients, with numerous examples in Britain, France, Germany, Japan, the United States, Canada, Brazil, the Philippines, and Australia. Examples are typically massive in character (even when not large), fortress-like, with a predominance of exposed concrete construction, or in the case of the "brick brutalists," ruggedly combine detailed brickwork and concrete. There is often an emphasis on graphically expressing in the external elevations and in the whole-site architectural plan the main functions and people-flows of the buildings. Brutalism became popular for educational buildings (especially university buildings), but was relatively rare for corporate projects. Brutalism became favoured for many government projects, high-rise housing, and shopping centres to create an architectural image that communicated strength, functionality, and frank expression of materiality.

In its ruggedness and lack of concern to look comfortable or easy, Brutalism can be seen as a reaction by a younger generation to the lightness, optimism, and frivolity of some 1930s and 1940s architecture. In one critical appraisal by Banham, Brutalism was posited not as a style but as the expression of an atmosphere among architects of moral seriousness. "Brutalism" as an architectural critical term was not always consistently used by critics; architects themselves usually avoided using it altogether. More recently, "brutalism" has become used in popular discourse to refer to buildings of the late twentieth century that are large or unpopular – as a synonym for "brutal" – making its effective use in architectural historical discourse problematic.

Unité d'Habitation de Marseille

The term "brutalism" was originally coined by the Swedish architect Hans Asplund to describe Villa Göth in Uppsala, designed in 1949 by his contemporaries Bengt Edman and Lennart Holm. He originally used the Swedish-language term nybrutalism (new brutalism), which was picked up by a group of visiting English architects, including Michael Ventris. In England, the term was further adopted by architects Alison and Peter Smithson. The term gained wide currency when the British architectural historian Reyner Banham used it in the title of his 1966 book, The New Brutalism: Ethic or Aesthetic?, to characterise a somewhat recently established cluster of architectural approaches, particularly in Europe.

The best known early Brutalist architecture is the work of the Swiss architect Le Corbusier, in particular his 1952 Unité d'Habitation and the 1953 Secretariat Building (Palace of Assembly) in Chandigarh, India. Brutalism gained considerable momentum in the United Kingdom during the mid-twentieth century, as economically depressed (and World War II-ravaged) communities sought inexpensive construction and design methods for low-cost housing, shopping centres, and government buildings. Nonetheless, many architects chose the Brutalist style even when they had large budgets, as they appreciated the 'honesty', the sculptural qualities, and perhaps, the uncompromising, anti-bourgeois, nature of the style.

Combined with the socially progressive intentions behind Brutalist streets in the sky housings such as Corbusier's Unité, Brutalism was promoted as a positive option for forward-moving, modern urban housing.

Smithdon High School (formerly Hunstanton Secondary Modern School)

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.

St. Peter's Seminary, Cardross, Scotland

Although the Brutalist movement was largely dead by the mid-1980s, having largely given way to Structural Expressionism and Deconstructivism, it has experienced an updating of sorts in recent years. Many of the rougher aspects of the style have been softened in newer buildings, with concrete façades often being sandblasted to create a stone-like surface, covered in stucco, or composed of patterned, pre-cast elements. These elements are also found in renovations of older brutalist buildings, such as the redevelopment of Sheffield's Park Hill.

Several Brutalist buildings have been granted listed status as historic and others, such as Gillespie, Kidd & Coia's St. Peter's Seminary, named by Prospect magazine's survey of architects as Scotland's greatest post-war building, have been the subject of conservation campaigns. The Twentieth Century Society has unsuccessfully campaigned against the demolition of British buildings such as the Tricorn Centre and Trinity Square multi-storey car park, but successfully in the case of Preston bus station garage, the Hayward Gallery and others.