I have a backyard of 30' x 40' and want to get someone to build me a deck. I was wondering if anyone had any experience with decks before? What I was wondering if its somehow possible to make two floors? Is it possible? (legal?) And if it is legal & possible, then let's say I have a first floor deck, and second floor deck, can I sit underneath the floor of the second deck? Because I want to somehow create more space... But not sure how.. I want to to 'deck out' my entire backyard.