The development of computational tools to aid with early-stage design of buildings is an emerging topic of great value. Developing a good conceptual design for a building is important because it can save a great amount of time and resources over the entire building process. This report discusses the project StructuralComponents 6, a continuation of the ongoing project StructuralComponents which focuses on the development of computational tools for conceptual building design. The goal of StructuralComponents 6 is to develop a tool for the conceptual design of mid-rise concrete buildings laterally supported by shear walls. The tool allows the user to digitally construct a prismatic, rectangular building design with a custom number and arrangement of shear walls, and performs structural validation of any given design in terms of stiffness, strength and stability. The project is split into three phases. 1) The conceptual design process is studied, and a framework of a conceptual design tool is developed. 2) A calculation method is developed that can be applied to a flexible number and arrangement of shear walls, assuming the shear walls are connected by infinitely-rigid floors. 3) The tool is implemented using Python and Grasshopper. A case study is performed to determine the applicability of the tool to real-life building design. It is concluded that the rigid-floor calculation method is adequate for the design of buildings with minimal out-of-plane floor effects (i.e. buildings with pre-cast floors). Through the case study, it is shown that the tool can be successfully applied to a building with a complex arrangement of shear walls.