I am building a detached 32x46 garage with a 16x46 room above built into the rafters. The roof will have concrete shingles and there will be a real field stone veneer 4' up the walls on both of the 32' sides and the over head door side. Typical 2x6 walls 16" o.c. With the entire interior insulated and sheetrocked. My concrete contractor is going to pour a 4" slab with a thickened edge and a 1' stem wall in a mono pour. My concern is all the weight. Do you think this foundation is sufficient or should I have footings poured and then pour a wall and then the floor?