This paper frames design knowledge as formalizable physical action for developing embodied computational design skills that can more fully exploit current and future digital fabrication prototyping methods. Digitally integrated prototyping tools reveal the physicality of cognition in computational design activity; however, because current theories of design knowledge define cognition as a mental process, physical computation design skills remain underdeveloped. We identify symbolic formalization as the root of this problem. We present a non-symbolic action-based notation drawing from embodied cognition as an alternative model for design cognition. Designerly knowledge is discussed in terms of reflective action and epistemic action.