Q. How do you make a hole in the ceiling?
A. In Premier, you can use a special tool found in Build>Floor>Hole in Floor Platform
For Home Designer:
Build four walls on the upper floor, defining the hole you want to construct.
Open the Room Specification dialogue, and under General>General>Room Type, select Open Below.
In Structure>Ceiling, disable all the options and press OK.
Select each of the four walls and use the Make Wall(s) Invisible button in the lower left corner menu to hide them.