Stair Tower on Universal

[umah]

Has anyone modified the Universal where they moved the stairs to the outside of the house, encased in a stair tower?  I would love to hear the pros and cons of doing this. 
In the game MineCraft, I make houses all the time and I always come back to the Universal, which is so sweet, simple and straight forward.   Adding the stair tower makes the Universal super sweet, and my family is on board with this idea, if it's feasible irl. 
What do you all think? 
Basically, I've shoved the stairs through the wall, plus a few feet more, in order to add a door on each side for future add-ons.  The bath/utility are deleted, and the kitchen and living are now the full 20'wide.  It's now an empty rectangle, basically.  I've added a master bd/w mbath along the kitchen wall, added 2 suites upstairs, plus a long loft, leaving the opening to the LR below.  (and of course, added balconies off both ends of the house. 
I know this sounds like a lot, but by doing it in stages, it might come to being afterall, if it's planned for it in the beginning.  (putting door frames in ahead of time, etc, even if we don't yet have the doors). 

Sorry, it looks like I've rambled, when all I wanted to do was to draw a picture of what's in my mind. 

[umah]

I take it nobody's done it, or that nobody knows what I'm trying to convey. 
Therefore, I took some pics... quite awful pics mind you, due to camera phone shooting the TV monitor, but they will have to do. 

Perimeter:


door on each side of tower for future expansions:


Stair tower allows for a 16' island kitchen and LR arrangement. 
!st floor:


2nd floor

[umah]

Added a mbd off the kitchen end:  (tiny gas dual sided heater)


Installed sunroom dining room, which acts as a mudroom in the winter:


Island Kitchen (have added a door for direct access to the BBQ)


Double oven/pantry side of kitchen with bd beyond:


A proper utility with 1/2 bath are added onto the back via the stair tower door
2 bds suites upstairs, plus a sewing/craft/homework station on the loft, with door to balcony.  Being claustrophobic, I also added a shared balcony off the upstairs baths. 
The Fireplace/LR is open to below. 

[John Raabe]

If you did a pop-out about 7'-6" wide by 8'-0" deep you would have room for the full sized "U" shaped stair shown in the Main Floor Plan (Sht. 1). It could have the full 2x6 wall framing to keep the insulation levels up. Working with the Typical Section (Sht. 3) you can just copy and move the stairway over. You can see that the roof of this pop-out is perhaps most easily done with a shed roof starting at the top of the second floor wall and sloping down at a more shallow pitch than the upper roof. I would do this with 2x12's to get good insulation but they could be shallower if you used foam insulation. If you set the stair landing wall at 6'-8" above the landing you would have sufficient headroom. Be sure to have a sturdy header over the pop-out opening.

[umah]

That's great news!  Thanks so much.  I wondered how to attach the roof to it, I can never do that very well in the MineCraft game. 
We're cutting the trees, sawmilling the lumber this year finally.      Now that we have a "concrete" idea, not only for us, but for future generations to expand as they wish to, I'm pumped. 
After we buy the plans and literally begin to build, I'll start a journal. 

Oh, and btw, the original plan works great in MineCraft too, especially when I push the kitchen table down to the now deleted main entry door, and use the slider door as the mud room entry.  Love it!!
Either plan will work, but I hope for the stair tower plan the most, especially during canning season. 

Thanks so much!!!