1st floor ceiling into 2nd floor

[scott65]

I have no doubt this has been asked and answered here before, but I'm not in the business, just a DIY'er trying to build a farmhouse, so I don't know the terminology to look for.  I'm trying to design a house that has 2 floors, but I want the 1st floor living room area to go all the way to the ceiling height of what is the 2nd floor for the rest of the house. The house is L shaped, the living room is one of the legs of this L shape.  So 3 sides, including the end gable wall will be exterior. 

 

The other end I'm not sure how to explain but I'm sure I'll need help creating it, even after I figure out the ceiling part in the main room.  It adjoins the kitchen at the other end, and a perpendicular hallway to one side leading into the other leg of the L shape.  I want the tall ceiling to end maybe 5 feet or so before the wall going to the kitchen, and this last 5 feet be regular ceiling height.  This will allow for duct work and give the room a little dimension.

 

Edit:  I think I just figured it out.  I found the option to set the second floor room type as "Open Below", that seems to have accomplished what I need

[katalyst777]

https://www.homedesignersoftware.com/support/article/KB-00358/automatically-building-a-one-and-a-half-story-roof.html