Together, the Level and Base Offset parameters define the lower boundary of a room.
In the room properties, the Level parameter is read-only. This parameter reflects the level of the plan view in which you place the room. For example, if you place a room on a Level 2 floor plan, the Level parameter for the room is Level 2.
Use the Base Offset parameter to indicate the distance between the base level and the lower boundary of the room. To use the base level as the lower boundary, enter 0 (zero). To move the lower boundary above the base level, enter a positive number. To move the lower boundary below the base level, enter a negative number.
For example, in the following section view: