Brandon,  Not sure if question was to me but I will give info on my setup.  I cut a rectangular opening in wooden basement wall of house and laid the garage floor heat through that.  I ended up filling in the opening with insulation before pouring concrete so concrete would not leak through and go into basement.  There is not a "rigid" connection so probably would allow for movement.

The same will be done for apron, I will push plastic tubing up through the wodden wall joists below garage concrete grade, then up into garage to attach to a manifold.  The area is on left side of left door as shown on picture.  The manifold will be a couple feet in the air attached to wall.  I burried the supply and return line in garage wall in that corner also.  Those lines had been foamed into wall and are laying in the blown in insulation in attic. the lines then go down 2x4 wall that was attached to mail wall of house.  I ended up putting a 2x4 stud wall up against the house for wiring and plumbing.  The house is 2x6 as well as garage and actually 2x4 and 2x6 on adjoining wall.

WIth electric boiler I could alwasy convert to a gas boiler in future if needed.