Thanks for your responses. We hope to be in TV before the year's end.
The plans I had used where the ones Xavier pointed out.
Having an engineering background, I'm familiar with plans such as these and how to calculate space. I gave it the benefit of the doubt by including everything possible and from outside walls. (btw a planimeter is a device to calculate surface area of any arbitrary figure; but I also tried to find the scales even assuming that the drawings were distorted and had different horizontal & vertical scalings).
I am aware that there are all sorts of additions possible (2' wall setbacks, cart space, etc etc).
Oh well, as they say "it is whatever it is".
I'm afraid I'm a bit old-fashioned. I just expect when the butcher measures out a pound the weight of his thumb's not in the cost.