The process is shown using pictures.

1) you have the building built


2) in the decoration section, select "remove decorative sidewalk"


3) hold down the "CTRL" button


4) now, you can delete surface


5) then you paint a decorative walkway under the building.


6) Just say thank you, you're welcome

This method will remove the ALLOWPASS prompt for pass-through buildings. The buildings will still be functional, but will no longer be passable for vehicles that do not have them set up directly on the line.