The paper discusses rule-based design strategies that allow for the generation of spatial complexity based on simple principles and taking as well the parameters of construction into account. The presented case studies as part of the academic project „Simple Complexities“ focused on the early integration of optimization parameters, regarding structural performance, physical properties and material specification as well as aspects of fabrication to inform the architectural design. The clear conception of a computation-process whose rules lead to certain formal and structural consequences is the necessary first step towards an architecture that is both structurally interesting and systematically coherent.