In seriousness though if one was to build a power house in the backyard to avoid risk of catastrophic fire, I'm thinking connect to the house via a 240/50A inlet and transfer switch by the grid meter, like if I was hooking up a portable generator. Then the only potential UL code requirement in the house would be the transfer switch/method. Could even do an interlock on the main panel. My big loads are all propane except central AC and that's only 2 tons. But then for the grid input to the inverters...another 240/50A in the other direction, from house to powerhouse.
If the powerhouse was in a trailer....nothing for code enforcement to get their panties in a twist about