As part of the research project ‘Carta della Cultura Industriale’ (CdCI - https://dtclazio.it/cdci ), which concluded in 2024, on the history of industrial architecture in Lazio in the post-war period (1945–1975), the authors of the contribution have concentrated their studies on the use of structure and technological component in the language of factory architecture. The text highlights the main evolutionary lines of this theme in the built works. In the absence of a real “style” dictated by the Cassa del Mezzogiorno Institute, as well as centralized typological directives, the designers involved in the construction of factories in Lazio pragmatically exploited the degree of formal freedom granted by the urban planning tools and building regulations of the individual municipalities. This allowed them to interpret the industrial theme, made specific by production and by the client, according to diversified construction and structural solutions. The common architectural and construction matrix of the Lazio factories was the specific training and experience acquired by the professionals hired, especially from the Roman area or school, particularly active in private residential architecture and ecclesiastical architecture. These were designers almost always interested in using the construction elements in a linguistic key - as in the most typical works of architectural realism - left visible in the facades characterized by details designed ad hoc. They also used the same approach when designing a factory, although necessarily recalibrating their design to the different contexts and economic availability of the intervention. Ultimately, the industrial heritage of the Lazio region represents a cross-section of what was happening in the rest of the country due to the technological evolution of the Italian construction.