solver

Because you did not build roof framing (the trusses), or any other framing.

When I bought Pro 10 years ago, one of the ways I learned the program was opening a dialog -- like Defaults. then clicking through each item. 
 
My goal was not to actually learn everything, but instead, I just wanted to become familiar with the program. I tried to remember the terminology -- what things were called, so I could look things up in help, or search online, when needed.
 

Start a new plan.
Draw four walls creating a room large enough to contain your stair.
Build a 2nd floor taking the defaults.
Back to the 1st (ground) floor, select the stair tool and click to place the stair. 
Move the stair so it's in the room if not already.
With the stairs selected, click the build stairwell tool.

Tip: Always say what software you are using -- Pro, Architectural or Suite, and the year, like Pro 2020.
 
Home Designer places all dimensions on a single layer with no way to change.
 
Interior and exterior dimensions are often shown on the same view. 
 
 
Make two copies of the file and do your dimensioning in each. Send your views to a common layout (may not work in older versions).
 

Please update your signature to 2025.
 
 
I was writing before you posted your follow up, but I'll add this.
 
The program changed recently to maintain door types when room types change. Before, it would automatically switch door types (interior/exterior) when one room was changed from/to interior/exterior.
 
The first image shows a setting that gives you control over both sides on an interior door.
 
 

It's a long time known bug. Check the Library and Bonus Catalogs for round windows.

Try to make it smaller by deleting everything but the structure. Then zip it -- just the plan file, don't do a Full Backup.
 
What does this say? Defaults are not very well thought out and can sometimes be confusing.
 
Image is from Chief Premier so things might look a bit different.
 

Because they are 2 different things.
 
Look under Account Settings for your signature.
 
 

You could use the Post tool.
 

 
 

Drag the tab to your 2nd monitor.

Place the newel manually.
 
Or, use a Pony Wall. Use a solid railing wall below set to be tall enough so the wall cap shows for your bottom rail. Normal railing wall above with no bottom rail.

That's what I would do using Pro or Chief because I can control floor and ceiling framing easily. Probably do this with Architectural too, but you will need to manipulate various dimensions to get the look you want.
 
With Architectural, I would experiment with using a thick ceiling finish. To increase that wall height, increase the ceiling height in the rooms, then add that same amount to the Ceiling Finish.
 
And please delete your thread on ChiefTalk via Moderator Actions near the top of the page.
 
https://chieftalk.chiefarchitect.com/topic/41697-how-do-i-heighten-front-walls-on-top-floor-without-higher-internal-ceilings/
 

You can set your newels to a 0" width, then place them manually (choose from library).
 

 
 
To force a full newel against a wall, pull the railing back from the wall, draw a Room Divider wall perpendicular to the railing, then another Room Divider from it to the wall forming a T.
Select the perpendicular Room Divider and move it close to the wall -- maybe 1/16" away. Then drag the railing wall letting it snap to the perpendicular Room Divider.
 

Using the Foundation Wall tool, draw the footers on the foundation level.

Your porch wall is not aligned with the house wall.
 

 
 
Aligned
 
 

Because that's one of the many things the people at Chief decided to omit from Home Designer.
Chief has all the functionality you desire, and it's all easy and automatic.

How did you rotate your plan?
 
In general, you should use Edit Area when rotating a plan. Grab the rotate handle and spin it around, or use Transform/Replicate to rotate an exact amount.

How did you rotate your plan?
 
In general, you should use Edit Area when rotating a plan. Grab the rotate handle and spin it around, or use Transform/Replicate to rotate an exact amount.

How did you rotate your plan?
 
In general, you should use Edit Area when rotating a plan. Grab the rotate handle and spin it around, or use Transform/Replicate to rotate an exact amount.

Ceiling height controls wall height -- and it does not matter if you uncheck Flat Ceiling Over This Room.
 
Roofs build over rooms.
 
With Suite, focus on the roof first. Once it's correct, you can turn off Auto Rebuild Roofs and remove the now unneeded interior walls that may have been required to make the roof build.

The framing isn't invisible, it doesn't exist. You need to build wall framing.
 
And you might review your wall definition. You have the exterior surface material set to be a paver and marked as framing.
 

I copied your data above, added a description to the first line and the import seemed to work.

@wrcolclough
 
My estimate was a bit off. It has taken over 3 hours to upload.
 
https://youtu.be/cVoVB5cZeyM