The article at hand follows the understanding that future cities cannot be built the same way as existing ones, inducing a radical paradigm shift in how we produce and use materials for the construction of our habitat in the 21st century. In search of a methodology for an integrated, holistic, and interdisciplinary development of such new materials and construction technologies, the chair of Sustainable Construction at KIT Karlsruhe proposes the concept of “prototypological” research. Coined through joining the terms “prototype” and “typology”, prototypology represents a full-scale application, that is an experiment and proof in itself to effectively and holistically discover all connected aspects and address unknowns of a specific question, yet at the same time is part of a bigger and systematic test series of such different typologies with similar characteristics, yet varying parameters. The second part of the article applies this method to the research on mycelium-bound building materials, and specifically to the four prototypologies MycoTree, UMAR, Rumah Tambah, and Futurium. The conclusion aims to place the results into the bigger research context, calling for a new type of architectural research.