Do you need to set up the floor manger first before creating the grid system?
Yes, the grids are generated by each floor. The floors to which the grids apply can be changed when necessary as the project proceeds. You can also apply different grids to groups of floors, e.g. lower floors may have larger floor plates than upper floors. We have tried to cover many possible options based on examples from a number of our users with quite demanding use cases. Note there is also the sketch grid option for irregular grids.