BIM plays a crucial role in the conception, modelling, and management of physical infrastructure, allowing architects and engineers to design within a 3D parametric environment. Unusual structural systems (e.g., buildings in seismic areas, tensile structures, reinforced concrete shells, diagrid structures) pose significant geometric, modelling, and analysis challenges. Conventional approaches with Revit and Robot, entail extensive resource allocation, are time-consuming and provide limited flexibility to accommodate significant variations. As a result, this case study investigates the automation of complex parametric structural systems. It explores the Revit/Dynamo/Robot interface and procedures to minimise data contamination, examines the flexibility to accommodate variations at any stage of the design process, and ultimately aims to increase productivity across the Atkins? infrastructure business. Several case studies have been investigated, and algorithms have been developed combining Dynamo's comprehensive set of pre-defined nodes, with the development of advanced Python coding. The case study begins with the development of an algorithm for multi-storey flat-slab buildings with stability to be provided by shear-walls in two orthogonal directions. Buildings in high-seismicity areas require a shearwall/floor plan area ratio of 1.5%, and specific Python code has been developed accordingly. Assuming even column distribution, constant floor-to-ceiling height, and regularity in plan and elevation, the algorithm is governed by six input parameters: Width, Length, Floor-to-ceiling height, Number of storeys and Column grid spacing (X, Y). No difficulties were encountered in the Dynamo/Robot interface. It then directs attention towards a second case study involving high-rise structures, and a third case study comprising complex surfaces.