Just a word of caution when you put an outlet every four feet in your workshop.
If you insulate it yourself, you will have to custom fit every third batt of insulation.
Just got done with the installation, and I think there were three batts that I did not have to cut to width, cut a section out of, or separate for the wires.
I was going to have it blown in like the house, but they would not be able to get there for a couple of weeks. I think it would have been about the same price, but I did not want to wait that long. It is 20x12 so it took me about 4-5 hours to get the ceiling and walls insulated and polyed.
Anyway, I am done and now my propane heater will roast chickens in there.