This research argues for novel strategies to integrate structural analysis data in architectural design. Instead of a linear procedure of analysis, synthesis, evaluation and post-rationalization a synthesis/evaluation loop is installed which embeds structural analysis data as design driver from early on. The approach regards structural performance as one design criteria within a network of different requirements. An equilibrium of multiple parameters is aspired to instead of a single-parameter-optimum. The research is conducted via a custom-made digital interface between 3d modelling software and an application for structural analysis of space frames. The information exchange provides the basis for successive strategies within a collaborative design process of spatial roof structures: negotiation of an overall form and a multi-dimensional improvement of space frame topologies by a Genetic Algorithm (GA).