My concerns with putting that build effort into storing a coach on someone's private residential property would be insurance-related. I'd make sure your insurance will cover any losses that occur there, and/or get proof that their property insurance would cover any losses to your coach while stored there. If that all checks out though, and you're comfortable with the other terms & costs of improvement, $100/mo for covered & powered storage is pretty good compared to my area (I pay 2.5x that for a commercial covered storage space with no electric, and am happy for it
).