I am remodeling a garage into a kitchen. i have the floor(plywood), wall studs and plumbing roughed. Brought in the electrician and he explained the soffit had to be built first and the bottom piece of drywall(to which the top of the cabinets butt up to) retreat in between the studs to the original cinder and brick wall for fire code. Is this correct. All i have found is that you build them after the place has already been drywalled. He explained fire inside the wall could get into the soffit space so they want that area closed off. Any advice is helpful.