Charrette is an education method that originates in the 1800s at the École des Beaux-Arts and is still common in art and architecture schools. Charrettes involve short sketching sessions that are based on improvisation and bricolage. In the last few decades, charrettes have changed their meanings. They've been used as a brainstorming approach in the early phases of collaborative design to create agreement, determine the project vision, and get the design process started. This study presents the idea of a new type of Charrettes that blends computational design with early brainstorming features of newer Charrettes and the improvisational aspects of the older. Thus, it may foster spontaneity, creativity, experimentation, and production while serving as a tool for collaborative computational thinking. The improvisations during Computational Charrettes state the priorities and intentions of collaborators in a short amount of time; therefore, they make the design process less time-consuming and allow for joint authorship. Improvisation is about attentiveness, real-time, and being in the moment, which is phenomenological notions. The pragmatic and experimental sense of improvisations combined with techné and technological context makes a post -phenomenological framework more viable. Our theory is that recreating the improvisational scene is only possible through understanding the postphenomenological framework of spontaneous acts. This paper conceptualizes a theoretical framework for Computational Charrettes by examining improvisations' interpretive, pragmatic, and democratic aspects. Following this methodology, we linked the sub-concepts of the post-phenomenological framework to the brainstorming methods, which can help to hold a Computational Charrette. Improvisations merge with Dewey's teaching of "learning by doing." We suggest Computational Charrettes can be part of basic design education studios by learning computational design through collaborative improvisations. Since interpretative, pragmatic, and democratic characteristics are closely related to education, we also included the educational components of Computational Charrettes during the post-phenomenological decomposition of improvisations.