Gus wrote:
..This way you don't have the roof inside the house on the second story. ..
Nice.
Select your roof. Click on the roof tool. Draw any polygon within the roof outline. This will become a hole in the selected roof. Permanent, but editable and deletable. And shows on the floor plan. As the others say, no need to use SEO.
The floorplan in Archicad is still symbolic, and doesn't show SEOs (Solid Element Operations or booleans). If you really need a "true cut" floor plan, you can do it by making a "3D cut" view in a Top View 3D window.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1