The redevelopment of the Post Rotterdam building and, in particular, the design proposal of the vertical foyer initiated this research project. The foyer has a special design and as a result, a special analysis method has to be used. The desired material is steel, consequently stiffened steel shell structure was deemed the most appropriate structure. Since the preliminary analysis of the proposed shape showed an excess of material usage, a research on modification of the shape and material distribution was decided to be undertaken, in order to reduce the estimated required material. A design process is being proposed in the research that includes the use of a genetic algorithm for the optimisation of the structure’s geometry, Python scripted algorithms for the distribution of the material and finite element analysis, given in the form of a design tool. The tool is created according to the requirements of the vertical foyer but it is also oriented for the analysis of other similar projects.