[ed_denu]

I understand your concern in looking to minimize the footprint space of an oven. Unless one has unlimited space available this is always a concern.

A properly insulated oven shouldn't transfer significant heat thru the walls. Beyond that I'm not sure I could offer much advise. The obvious questions would be how do you seal the oven walls to the building cutout, where do you mount the electronics, etc. I suppose you could paint the outside of the oven, or use aluminum sheeting, but that would be rather expensive.