Alejandro Zohn (1930-2000) studied both at the same time civil engineering and architecture in Guadalajara, Jalisco, Mexico. From his student times he became interested in the plastic and formal qualities of ruled structures and concrete. This is evidenced by his final works and his engineering thesis "Nuevo Mercado Libertad” in the San Juan de Dios neighbourhood, in 1955. A couple of years later, the thesis became one of the main buildings in the city. This design project will determine his personal path in architecture: using the hyperbolic paraboloid, a ruled surface that solves not only the roof but the entire building, obtaining spaces of great interior and exterior expressive richness, which are halfway between architecture and sculpture. Added to this is the use of a reduced range of traditional materials in conjunction with industrial materials. This article explores the origin of this way of designing and unfolds the compositional mechanisms that the architect-engineer uses in his design projects. Starting from a basic unit that, singularly or systematically repeated, solves a wide range of architectural typologies, Zohn creates a set of masterful works that have spatial qualities in accordance with the specificity of the place, with the properties of the materials and with the programe requirements.