Leeds Station Southern Entrance (LSSE) is a signature new gateway entrance to the existing station in Leeds, United Kingdom. Constructed over the existing river between 2 residential tower blocks, and supported from the existing station structure and Victorian masonry arched viaduct, the site constraints alone make this a challenging scheme. When combined with the multiple curves of the architectural form, it presents a unique set of engineering challenges. This class will be a case study covering how we’ve successfully used multiple Building Information Modeling (BIM) tools (including Rhino software, Grasshopper software, Robot Structural Analysis software, Revit software, and Navisworks software) to engineer a scheme that would be impossible without today's technology and to bring the existing and new build elements together seamlessly. We will discuss the project constraints, the workflows used, and some of the challenges we overcame in design and construction.