Currently (pun) power runs to the house then back to the existing shop. Idea would be to run in 2 x 200 amp service to the shop and run the second 200 underground to the house and eliminate the overhead wires, mast and meter on the house.
I was reviewing this thread and failed to notice this issue earlier.
As I understand it, you will be operating your shop as a business. That means that water, heat, and power are all eligible business expenses. One of my biggest issues with that has been separating those costs for the house from the costs for the barn.
I did a SWAG initially. But more recently I bought and installed an Emporium Power Meter. It will monitor panel usage as well as individual circuits. That meant I could keep a record of barn power usage. It also meant that I could monitor the radiant heater power usage which could then be translated into gas usage.
If I was doing it from scratch, I'd install separate meters.
As a side benefit, that would mean I could have separate supplies and not worry about which building is serving which building. The utility companies would probably want to fight it, but I bet one could find a way around that.
Edit - having separate power consumption for the shop also means that you can approximate the heat loss factor. (power and energy input required to maintain a given temp differential.)
Edit 2 - since I understand that you are starting an HVAC business, this info could also be a valuable marketing tool as well as yet another writeoff......