Second Floor Structure Question

[ACADuser]

My first project is nearing completion of the basic plan.
The elevations look good to me although need clean up & annotating.
The 3D view is working except for the ceiling height in the lobby area.
If you look close at the attached picture you can see the ceiling through the upper windows. That area is supposed to have a 12' ceiling ans all else a 10' ceiling.
In reality the architect wants a 10' & 12' drop ceiling and I put the hard ceilings at 10-8 and 12-8. The actual building will have 10-8 & 12-8 CMU walls with 24" web trusses sitting on the walls.
Then a plywood deck & 2x8 frame parapet walls. The flat deck roof will be stepped over the high ceiling area & tapered insulation will provide roof drainage to the right wall where the parapet wall is at 0".

But I drew the structure as two floors with no roof. Using the 2nd floor as the roof. 1st floor ceiling is at 10' and 2nd floor thickness is, well I'll attach the structure dialog for you to see.

How do I get the lobby ceiling to 12'?

I plan on using ACAD to do the structural sheets as I am still too slow with CA and don't know how at this early stage of learning.
 

[HumbleChief]

Any separate area that you want at a different ceiling height needs to be separated with a 'room divider' wall. That area can now be defined with its own ceiling height.

[ACADuser]

OK I think I can do that. The lobby square footage required I put invisible walls but part of the reception are will be raised as well. See attached.

Not sure how I can add more invisible walls without messing up the reception area square footage.

 

[DRAWZILLA]

I  see you have a 30" ceiling and floor structure, how did you create that, might make a difference. Something doesn't look right with those.

[CJSpud]

You might be able to model your tapered foam pieces on the roof deck using polyline solids.  You would have to draw them in a cross section view and then go back to plan to get their edges in the right place (i.e., change their thickness to the area being covered).  This will work if the tapered pieces are square or rectangular - which would likely mean at least one side doesn't have a parapet wall but rather an eave for drainage. 

 

If your roof is designed to have some that have angled shapes sloping to roof drains or scuppers along the parapet walls, you could do that with roof planes.  I had a southwest design project a few years back and I used roof planes to do the slopes to the scuppers locations through the parapet walls.  You can just draw the roof planes off to the side; get their spec's, dimensions, etc. as needed and then use the point-to-point move tool to put them over your floor surface.  It is easier to just draw them in place and shape as needed and use the join roof planes tool to join the valleys etc. as required.

[Joe_Carrick]

Perry is right,  You have the Second Floor structure set at 30" and the Ceiling Structure also set at 30".  These values automatically set the ceiling height below at 120".  All you need to do is change the Floor Structure to 6" which will raise the ceiling to 144".  If you need more than a 6" Roof Structure then You will need to change the "Floor" Elevation of the Roof.

 

Note:  In Chief, the Floors above effect the Rooms below.