Free Download PROISAC-BIM-VDC Grid Vertical Extender 4.0.0 | 1.8 Mb
Forget about missing Grids in your floor plans and having to manually search and extend each Grid. Now, using GRID VERTICAL EXTENDER you can extend Grids vertically to the selected top and bottom levels quickly and easily in just a few seconds. Also, you can apply an offset to the top or bottom level as well.

https://apps.autodesk.com/