Looking for ideas on how best to maintain thermal consistencies and structural integrity on altering this design (see pic below) to:

1) Make a consistent/homogeneous roof profile across the entire front (match gable end of this wing section to that of the main section of the building).

2) Increase cover area over porch.

The building’s roof will be a cold roof.  Metal roofing.

At this point I’m leaning toward an insulated raft slab foundation.  This presents concerns with how to carry out the porch decks, which are depicted as concrete here.