A grid will serve as a datum for elements like columns, beams and walls. In this video you will create the project structural grid by setting up a simple sketch grid based on the conceptual diagram.
If you would like to work hands on with the videos please visit the Bentley Learn Server and download the dataset from the course 'Learning OpenBuildings Designer - Modeling and BIM Essentials'.
https://learn.bentley.com/app/Public/ViewLearningPathWithMasterCourseExpanded?lpId=116818&mcId=103962