Yes, find an Architect. A deck over an enclosed space is more complicated than a freestanding deck on grade. An architect will know the various deck systems and find one that suits this installation, budget and develop a specification so you can get bids and a permit. There are low profile, adjustable pedestal deck systems with wood or pavers that would likely work here with door threshold height. Check out companies such as ”Archatrak”. If your roof system is 17 years old, then it is not reasonable to install a new deck over it. I would put the best roof possible, say a hot mop system, which will give you a much longer life that a what you currently have.
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