As a highly interdisciplinary field, architecture is being influenced by many subjects of natural and social sciences. Biology despite being apparently distant from architecture is currently a scientific field blending into design practices, which have evolved and shifted towards a new hybrid framework. In this article, we present an emerging design field of what we categorize as biomimetic architecture pioneering by six architectural offices in France. We observe the impact of scientific researches on design processes and practices through six case studies led by these offices, which can be seen through the actors who involved in various types of interdisciplinary collaborations, through the competencies of the architect himself, and through new sources of ideas coming from biological sciences and related fields. We propose to use a classification of theoretical uses in modeling practice to better understand the role that biological knowledge plays in architectural design practices. Finally, the result of this analysis shows that the use of biology taking place in a design space has external purposes, which transform it to produce engineering devices or urban schemes rather than architectural projects. It also shows that biology in architectural design induces other kinds of non-biological knowledge, is not strictly theoretical and could be obsolete or approximate. These findings lead to an epistemological discussion concerning the confusion between biological ‘knowledge’ and architectural design ‘know-how’.