Thèse en cotutelle En vue de l’obtention du Doctorat en Architecture de l’Université de Toulouse Jean Jaurès/ Ecole Nationale Supérieure d’Architecture de Toulouse, Et du Ph.D. Individualisé en Architecture de l’Université de Montréal, Présentée à l’Ecole Doctorale TESC Université de Toulouse Jean Jaurès. Unités de Recherche : LRA – Laboratoire de Recherche en Architecture LEAP – Laboratoire d’Etude de L’Architecture Potentielle / L’état du développement de la théorie sur les modes de représentation ne contient que peu de travaux sur la coupe architecturale, notamment au XXe siècle, époque à laquelle la notion d’espace devient un enjeu architectural propre à la modernité. Cette étude théorique établit les conditions du recours à la coupe dans l’élaboration d’une spatialité qui fournit du sens au projet. Elle propose au préalable sur une investigation des façons de voir un édifice ouvert, de la ruine à l’écorché, permettant d’extraire quelques ressorts disciplinaires de la coupe. L’exploration de sa contribution à « la résolution du projet dans l’espace » qui constitue le cœur de ce travail, est guidée par l’analyse approfondie de la fabrication d’un corpus de coupes d’espaces domestiques emblématiques du XXe siècle. Elle éclaire ainsi, in fine, sur son usage et la connaissance de son statut, au seuil de l’hyper-développement de la modélisation. / Seeing architectural space in section exploration of the section in the conception of modern space. Progress of digital technology allows hyper-developing of representation modes free from instruments which are more and more considered as obsolete to produce new spaces. However, referring to the spread which is given to the section when presenting projects, or in teaching practices, it is often described as a device for stimulating, designing and building. This theorical research observes the use and the status of section at the end of the twentieth century, at the dawning of modelling development. According to Jacques Guillerme and Hélène Vérin , section appears within surveys and studies of antic ruins as a physic reality, the one of a building truncated by its own partial collapse. Many theorists, as Barbara Stafford and Robin Evans , make a connection between section and dissection as opening modes on the inside and by the development of both practices during the Eighteenth century. According to Robin Evans, to reveal the essence of the building is the real function of architectural drawing. The approach is to explore the drawing and the evolution of sections through traces of the designing process, in order to understand how section act as a “générateur” of the project. The research question may be : How, and to which spread, architectural section has a generating dimension of space and it intervene in the elaboration process of modern houses designed after the “Resolving the project in space” ? Based on archives drawings a reference corpus of six modern emblematic houses sections designed between twenties and sixties have been observed in their representation and space. Six other emblematic houses sections conceived from seventies to two thousand ten have been observed through a comparative analysis with the reference corpus. The expected results are to detect the spatial issues raised by the section, to extend its agreed definition as a representation tool to a designing tool and to settle a methodology for analysing cut space.