This paper will report on a generative performative modelling approach that engages architects and structural engineers in close dialog. We focus on knowledge shared between architects and engineers to apply the Finite Element Analysis based structural design technique Evolutionary Structural Optimization [ESO] as a way to understand or corroborate the performance factors that are significant in determining architectural form. ESO is very close conceptually to the dynamical system of matter and forces of growth itself. It has parallels both mathematical and metaphorical with natural evolution and morphogenesis so it has been poignant to apply the approach to a formal architectural case study in which the generative influence of these processes is inherent.