alt Hacker News> no building permit is required
This will be the main issue. No matter what you're going to be doing work inside the main service panel on your house adding new feeds and you'll need to install a transfer switch to disconnect your house in case of a power outage. Most electrical work inside a panel like adding circuits will require a permit in the US. Seems like your plan doesn't involve any of that though so you should be ok permit wise except maybe needing one for the pad and structure.
It would also be nice to think of your neighbors in terms of not starting a fire and someone capable of doing permitted work will be handy when you go to sell the place and bright red flags show up during inspection.