Stepped Thickened Edge Slab

[LeahSnowSpruce]

I am trying to build a house with a thickened edge slab. I want to drop the garage for the house by 3", but I want the bottom of the footing to be at the same elevation as the bottom of the house footing. So I made the footing 3" shorter to match.  This worked except at the house wall.  The footing where the house and the garage meet drops an extra 3" beyond both footings and forces a chamfer (I have chamfered the other footings) under the garage floor, which I do not want.  Any suggestions? I have included a picture of how it looks, and a sketch of how I want it to look. Any help would be appreciated...