Architecture’s progression into the digital age is fundamentally changing contemporary practice due to the rapid development of digital tools available to architects, which are deeply affecting how projects are conceived, formulated, developed and constructed. The emergence of Building Information Modeling (BIM) has reached unprecedented relevance at the beginning of the XXI century within some academic and practicing architectural sectors. BIM tools are usually based on parametric design, a method that allows the design of element behavior through powerful linkage methods with changeable dimensions. Parametric tools are enabling the use of complex geometries, and have produced a multitude of highly suggestive freeform projects. For many architects, these developments are viewed either as banal proposals, products of digital intelligence (Meredith 2009), representative a mature style (Schumacher 2008), or even changing the very basis of architecture. These positions coexist, gravitating between unconditional support, skepticism, and criticism, and share a generalized ambiguity with respect to their underpinning fundaments and principles, which has created widespread concern amongst academia and practicing architects. This research theorizes that parametric design is not only a powerful tool and a product of digital intelligence, but that it’s also an important “logic” found persistently within the history of architecture. In particular, several architects and engineers started to formulate parametric concepts throughout the XX century, initially without the use of computation. These early experiments represent architectural production of significant quality, but despite their pivotal contribution to innovation, their legacy is currently absent within architectural practice and theoretical discourses, due to the lack of research about their guiding principles, historical references, and conceptual developments. A genealogy of over 40 selected projects has been constructed, with each exhibiting parametric logics throughout their conception, design and construction, before the use of digital tools from 1890 to 1980. These projects are reconstructed digitally using current parametric platforms (Rhino with Grasshopper plug-in) to unveil their generative logics and study their underlying codification. Their basic parameters are revealed, which testify a close relationship between materiality, construction systems, geometrical bases, and structural limitations. Multiple genealogies between projects can be traced, allowing further relationships and sequences among innovative research agendas. Furthermore, important collaborations between the project´s authors are revealed, within a body of knowledge that still remains unknown to a vast architectural community. Proving that the use of parametric logic is historically deeply interwoven into the interdisciplinary nature of innovative architectural practice, this research identifies that current digital tools are continuing these logics, and are extrapolating them to unforeseen levels. By questioning some of the superficial and misinformed opinions that are currently abundant within the realm of architectural digital production, this thesis provides a series of theoretical and practical precedents, which were developed prior to the appearance of digital tools. This knowledge should be continued and expanded to help resolve current discrepancies between advanced architectural practice and some traditional theoretical discourses. If the practice of architecture must respond to the paradigms of its time, it is imperative to situate innovation within a coherent and rigorous architectural knowledge that is part of a permeable and always alive and changing architectural history (Giedion 1941)La rápida diseminación de herramientas digitales ha generado un profundo cambio en la practica arquitectónica contemporánea, afectando como los proyectos se conciben, diseñan y construyen. Uno de los aportes más significativos dentro de las herramientas digitales a principios del siglo XX es la aparición del modelamiento computacional en 3D o BIM, un sistema basado en diseño paramétrico, que permite diseñar relaciones entre elementos en lugar de producir objetos dimensionados. La amplia difusión de diversas plataformas digitales paramétricas han alcanzado una importancia sin precedente dentro de sectores arquitectónicos vanguardistas, generando una proliferación de proyectos altamente sugerentes de “formas libres”. Estas propuestas provocan reacciones disímiles dentro de la disciplina arquitectónica, y círculos académicos como profesionales gravitan entre reacias críticas, un acentuado escepticismo, llegando incluso hasta un desmedido entusiasmo. Pero en general, estas posturas develan una preocupante ambigüedad y confusión, debido a la falta de estudios con respecto a sus orígenes, relevancia y fundamentos teóricos. Aunque gran parte de la disciplina arquitectónica asocia lo paramétrico con el desarrollo de técnicas computacionales, esta investigación plantea que lo paramétrico como lógica aparece persistentemente en la historia de la arquitectura desde antaño. Estas lógicas surgen inicialmente sin el uso de la computación, manifestándose con intensidades fluctuantes a lo largo de la historia, y apareciendo con un protagonismo inusitado durante el siglo XIX y XX. Este valioso legado arquitectónico reclama ser rescatado y revalorado, para construir un discurso de continuidad entre quizás viejos paradigmas, que hoy resurgen como preocupaciones contemporáneas, adquiriendo nuevas dimensiones y potencialidades. Esta investigación identifica alrededor de 40 proyectos construidos durante el siglo XX que utilizan estas lógicas, analizándolos mediante una reconstitución utilizando sofisticadas herramientas paramétricas digitales. El análisis interrelacionado de proyectos permite situarlos dentro de una tradición de continuidad disciplinar, demostrando el impacto de los avances tecnológicos en varios ámbitos (técnicas constructivas, materialidad, diseño, etc.), y el carácter multidisciplinar de los proyectos. Esta aproximación metodológica permite analizar los parámetros base, sus sistemas de relaciones, enfatizando la serie de transformaciones necesarias para generar la forma, para finalmente develar argumentos, conceptos y principios para ser aplicados en la práctica arquitectónica contemporánea