Thank you for the suggestions. In my version, I cannot build foundation walls, which is very disappointing. All I can do is play with what the program generates and copy other foundation walls. As soon as a foundation wall is attached to a room (and I cannot find a way to disassociate it) on modifying it, the program automatically alters all foundation walls connected to it, similar to what the divided room is doing, so I can't add that wall there.
Sidewalks disappear inside the house as well, first thing I tried was that.
I tried putting in a landing after deleting the divider, but the stairs just ignore it like it's not there. I erased the stairs and regenerated but same effect. the landing is larger than the stairs and completely filling that side of the room and the stairs are placed on top in the corner.
As a work around, I have added a 5th step and set the stair treads where they should be, then raised the landing an inch to hide the first step and that is fairly close to the actual house.
The purpose of this house build is to get as close as possible to the existing house, for purposes of building a substantial renovation in the future. These stairs will remain and there will be a flight in the same direction, in that garage directly above them going to a second floor, so clearances are critical. The suite above main entrance will be the stairs above and must meet minimum codes, from my hand drafted drawings, it looks like I have clearance but this program will allow me to visualize and measure more accurately. I somehow managed to get that side of the house and garage dimensions accurate but the foundation and stem wall got messed up at the front of the garage and the exterior 4' section on the left of the garage, so I had to erase all walls around the garage and set foundation back to auto, build the garage expansion and put the original walls back, then take auto foundation off and copy foundation walls to set in the interior ones that have perimeter foundation under them. I will have to sort out the garage floor again later.