This thesis explores the procedural generation of 3D buildings from the floor plan all the way to the fa¸cade and building’s details such as doors, windows, and roof. Through this, the study explores several techniques and approaches to create different layers of the building generation pipeline. The focus is on implementing a set of algorithms that, when running sequentially, are able to create complete 3D buildings in a short time (so they can be used in online generation), could be used in any open-world game, and with a limited count of triangles per building. Furthermore, the tool provides a clear and easy-to-use interface for designers in Unity, where they can interact with the multiple parameters of each building layer, giving designers a high degree of controllability. The tool is evaluated using the resulting buildings based on different metrics and how individual changes to different parameter starting from a template affect the output of the generator in terms of the metrics and the resulting building. The result from the analysis show that the polygon mathematics is well suited for generating 3D buildings for games.