Sure, the city might have noticed the stair error but they would have had no obligation to you to do so; they could have issued a permit and then flag it as a violation after it had been built, so never rely on an inspector for code compliance, that's your responsibility even if you hire a designer and a builder. Regarding the future room square footage, are you asking about zoning ordinance, building code, sewer/septic, or HOA regulations? I can't think of any maximum square footage restrictions in a building code; it is primarily concerned with safety and energy conservation so if you show a door to the space you must give it a use and design the floor structure for that use even if it is only storage. So call it storage so you don't need emergency escape windows and design the floor structure for a bedroom/living loading. You would probably show exterior insulation, a utility light, subflooring and omit all finishes. Are you suggesting that you might build above the Great Room later? Incidentally, a two-story space on a corner of a building needs additional attention for lateral bracing because wind forces are greater at corners and it is the floor that provides bracing for exterior walls so be sure to hire a good structural engineer.

I don't mind a family style upstairs like you have with no master suite. We have something similar and it works great. We hated the master suite in our old house and one central bathroom works much better for us with kids. I do think the hallway space needs some work. I get what you are trying to do with the bak of windows and the laundry room and 3 bedroms but if you look at the door placement it seems like only a small area of the loft/hall will be useable for crafts and sewing or a playroom. The area between the doors and the stairs is as large as a bedrom and you won't want a table or shelves in there. What about making a room in the area at the bottom of the drawing and using it for a large family bath and laundry. Then the area currently roomed off for bath can be an open loft. It will actually feel more open because it will overlook the stairs but it still doesn't address the large space between the bedroom doors.

Mjlb: Yes! One bath could be accessible from hall. If you have ideas, I would love to hear them. I should have added I planned to eliminate entrance to Master closet from hall anyways. That's just weird to begin with. I really want my daughter (who will be the oldest child) to have her own bath, which is why I wanted to do the en-suite baths. In regards to thinking in 3D, trust me, I have....or trying to anyways. I have a program I use (not a professional but it helps with the visualization.) The bumping out is actually creating a larger family room below, which is why I want to do it, not just to create a larger Master. Plan has two fireplaces. Both are listed as optional, so I have so wiggle room there as well. This is a stock plan, Unfortunately a truly custom plan is not in the budget. I love so many aspects of this plan, especially the exterior.

I have thought more about this. Like Beth said, you could really get a lot more in that bathroom with only one door. I think I drew what she suggested. As far as the door between the two areas, I think it could go either way, but if possible, I think a pocket door that slid into the area by the tub would be better. This would keep the door from being in the way and be almost entirely hidden if not in use. I had one additional thought as well. Assuming later down the line there are additional children or the house is sold to someone with more than one child and bedrooms 3 or 4 are used as bedrooms. Is it going to be fair that the bathroom opens into bedroom 2? Seems like that might cause some disagreements. On that same thought process, the one thing that might bother me would be seeing into the bathroom from downstairs. Although this puts you right back in the same position having bedroom 2 walk around the corner to get to the bathroom, the view from below will be nicer and access will be more even between all 3 bedrooms. If doing something like this, I would extend the vanity the entire length of the room for plenty of storage underneath. (This is the placement of the bedroom door from your first drawing.)