like i said before, i hope you dont use 400 amps.
what are you guys doing running foundries or growing dope in your basements???
Just planning for the future:
100a to detached shop
50a hot tub
50a pool(might be 60 actually) not counting a possible pool heater(although would likely plumb to my propane)
50a plug for car charger(dont currently have, but doing to future proof)
dual all electric HVAC is 40a a piece so 80a total
dual electric hot water heaters are 30a a piece so 60a total
electric oven is usually 30a
exhaust hood for gas cook top is 20a
washer/dryer is 2 circuits(15a/110 and 30a/220)
plus all the other stuff im not thinking about(all outlets, lights, home theater, etc...).
I am reasonable confident I wont be running it all at the same time obviously, but I could see a few situations where exceeding 200a could be a possibility(lots of guests say at Christmas time so both HVAC heaters are running along with both hot water heaters, oven, hot tub heater, etc...). The biggest issue is running out of breaker space as I outlined earlier. 42 breaker spaces in a 200amp panel will get tight really quick. My 2200 sq. ft. current home has the breaker panel maxed out after I put in 50a for hot tub and 50a for welder circuit and the house we are building is going to be almost twice as large. This builder when you spec the pool stub and hot tub stub have a caveat that it "may require" an upgraded electrical service. Im just doing it, im not going to ever worry about power capabilities.