By chief architect.
Build attic chief architect.
It s easy to manually create attic walls to fill in gaps such as in gables where the program can t determine where one is needed or if you have turned off the automatic generation of attic walls.
To modify the area above the garage using the select objects tool click in the area or room that is above the garage on the 2nd floor to select it and click the open object edit button.
The bottom line is this.
With pro you can lock certain roof planes and perhaps leave auto roof on but it is best not to rely on that.
If you have a half story structure you must learn to live without the auto roof build function once you have built the roof.
To manually add a gable wall.
Certain conditions must be met before an attic truss can be built.
If this is the case you will need to.
The structure should be sufficiently wide to allow for a loft and attic spaces the loft area must be on a living floor and have attic rooms on both sides separated by knee walls a flat ceiling in the loft area and a floor below steep enough roof pitch to provide appropriate ceiling height for the loft area.
On the structure panel of the room specification dialog that opens lower the finished ceiling value to the height that you want the exterior.
Repeat this process for the opposing gable wall on this floor.