[folivier]

I've seen Steve's garage and it is a great size that allows him to work on it without having to squeeze by when all slides, bays, and engine compartment is open. Also a great idea to have the lights on the sides.
So IMO the question is does your friend want to provide just a storage or a place to also have the slides open and be able to work on whatever is needed? But the contract would have to have something to specify what type of work is performed. Would he allow an engine overhaul? Or just oil changes, routine maintenance, or just cleaning?
It sounds like he has the opportunity to provide a really nice storage that will appeal to high end coach owners.