Set two computation heights for one room

Hi, i need to get the area of one room in two different heights. The room is under a roof with a slope.
I know how to set the computation height for a room once.

It is possible to set it twice? so i get for every Room two calculated areas?
Is there a other way around? Any idea would help (also difficult solutions with python)!

Well…i got it myself;)

1.set computation height to 0.
2.room to solid
3.create planes at your two heights
4. intersect solid with the planes
5. get area of the two intersect surfaces