Hello

Right...  since grids are currently stored per-building + floor, and buildings are stored in the project's Floormaster file, I'm not sure if there's any way to have grids per building stored in the same project.  

That's why Eric had suggested using separate projects since that should allow different building + floor + grid.

do you mean that i  must have floor master "BB-floor master "  file for each buidling ?

yes you do

It depends on how you to that also.  If each building is the same project then only one BB-floor Master.

If each is a different project then yes one floor master for each.

Then also you can point all projects to the same BB_Floor_Master in your settings under Workspace preferences (all project) on within your Project user.ucf file for that project only (make sure to lock the variable)

each building is the same project , but each buidling has its own grid , what should i do ,

if i make floor master file for each building , is this will affect another sitting ?