This paper is part of a broader research agenda, which aims at an environmental re-reading of selected icons of Modern Architecture that share one characteristic, the development of a free-flow open section. The complex relationship between spatial composition and thermal and climatic conditions within buildings is explored both qualitatively, using analytic drawing, and quantitatively, using simulations with computational fluid dynamics. I am seeking patterns common to both and the work has become an investigation of the concept of architectural space at the intersection between art, technology, climate and perception. Most architects of the Modern Movement addressed this relationship in one way or another. They either praised technology and the emerging ‘machine age’ or rejected it. Today most architectural production appears to have an ambivalent and sometimes contradictory position on technology.