In his lectures at the University of Pennsylvania, Louis Kahn loved to recount an imaginary dialogue with the material he was about to use: "Ask the brick what it wants to be. The brick says: I like an arch. And if you say to it, arches are expensive, I can put a concrete lintel over you instead — what do you think, brick? The brick says again: I like an arch." The anecdote, often quoted out of context as a rhetorical flourish, actually expresses a precise design principle: every material has a structural and formal logic that's its own, and the designer's task isn't to impose an alien form on it but to listen to what that material, given how it's made, does best.
Louis Kahn: the brick that carries itself
Kahn applies this principle most consistently at the Indian Institute of Management in Ahmedabad (1962–1974), where brick isn't a cladding but the actual load-bearing structure: huge arches and circular openings in brick masonry, substantial wall thicknesses, surfaces left raw and unplastered. The complex, built with local labour and materials in a climate that makes brick (fired with traditional Indian techniques, often in pit kilns) an economically and climatically logical choice, becomes a manifesto for the coherence between available material and architectural form. At the Phillips Exeter Academy Library (1965–1972), Kahn uses brick for the load-bearing outer envelope — piers and arches in solid brick — while reserving concrete for the double-ring inner structure that organizes the reading spaces: a hierarchy of materials that mirrors a hierarchy of uses, from protection from the outside to spatial freedom on the inside.
Herzog & de Meuron: brick as texture, not as mass
Herzog & de Meuron tackle the problem from almost the opposite direction in the Tate Modern extension in London, the Blavatnik Building (2016): a 65-metre tower whose outer envelope is a lattice of perforated bricks arranged in a pattern that lets light through, not a solid load-bearing masonry as in Kahn. Brick here isn't the structure — the tower has a reinforced-concrete frame — but a visual and climatic filter, a "skin" that talks, in scale and colour, to the brick of the neighbouring Bankside Power Station, the decommissioned power station that forms the museum's main body. It's the same "phenomenological" approach that characterizes the whole studio's material research: not asking what a material looks like in the abstract, but what that specific surface does — in this case, how it filters light and how it converses with the site's industrial memory.
Aldo Rossi and the brick of the city
Aldo Rossi takes brick in yet a third direction: that of collective urban memory. At the San Cataldo Cemetery in Modena (1971, completed in the years after his death), face brick clads elementary, repeated volumes — cubes, truncated cones, a long portico — in a composition that explicitly recalls the typology of the traditional Italian house and city built in brick, but emptied of any residential function: it is "the city of the dead" built with the same material as the city of the living. In Rossi's theory, set out in "The Architecture of the City" (1966), brick is never a neutral material: it carries with it the typological memory of centuries of urban building in Lombardy and Emilia, and it's precisely this memory — not technical performance — that makes it the appropriate choice for an architecture that wants to be recognizable as part of the historic city, even when the function is radically new.
The thread linking these three approaches, apparently very far apart from one another, is that none of the three treats brick as a cladding interchangeable with any other material by purely aesthetic choice. Kahn listens to it as structural logic, Herzog & de Meuron use it as a perceptual filter, Rossi uses it as typological memory — but in all three cases brick carries a meaning that no other material could carry in the same way.