This dissertation seeks to bring material experimentation to the forefront of design by associating it with computation and fabrication technologies that challenge the current disciplines of digital fabrication in architecture. The idea of transient materialisation is not primarily interested in the representation of digital geometry; rather, it considers the process of morphogenesis that emerges when multiple factors, such as geometric data, differentiated material states, machine capacity, fabrication timing and environmental stimuli, influence and construct within each other. Because this process is an intricate correlation, feedback analysis serves as a design medium in which to explore new forms of architecture through numerous digital and physical experiments. In addition, transient materialisation not only advocates for embracing indeterminate material effects for further investigation of material aesthetics it also challenges both the perception and sensoriality of architecture. Hence, to examine this research direction, this thesis conducts a set of experimental projects through hands-on material experiments as well as the development of software and prototyping machines. Collectively, the dissertation proposes a framework for the discussion of transient materialisation across three dimensions (ephemerality, dematerialisation and coagulation) through these experiments.