I'm finishing up a 30x56. I have a 10' wide porch on one side. It has a full kitchen, and bath and completely finished with drywall. It also has a forced air HVAC in the living half and a mini split in the shop side. I contracted it myself and it has run just a little over $65 a sq ft.
Sears had a large if not the largest distribution center in Greensboro, NC. In their catalog they also sold an all steel house kit. There is one in Greensboro on Lawndale Ave not far from the distribution center building.
You can put two HVAC systems in to achieve the separation. I'm building a 30'x56' with about half of it people area. I put conventional forced air heat pump in the people area and a mini split in the shop area. I also insulated the wall between the two areas.
Hey Rabbit. I'm wiring my shop as we speak. I know I tend to be on the over kill side. But as I see it it's just a few more feet of wire and a few more circuit breakers. I'm putting two or three outlets per circuit. That way most every other outlet is on a different circuit.