The process goes like this....

Send in application with plans to the ZBA.
Automatically get rejected and sent back to community association.
Contact local community association.
Go before their zoning committee.
Get letter of approval (assuming they approve - most require the deck to not be visible from the street).
Go back to ZBA.
Hope they approve you.
Get permits.
Build deck.

As for what the requirements are, it depends. For the most part, they require an actual door out to the deck...no roof hatches or window access. A real door and real stairs. Not sure if they will approve a spiral staircase outside the house. If the stairs come up through the roof, you have to build a little "house" (I'm sure there is a word for it but I can't think of it) on the roof like this:



I'm sure there are other requirements as well.

As for value, I think most people will tell you that it may add value, but rarely will you recoup the costs associated with adding a deck (at least if you do it legally with plans and a contractor). In other words, if you spend $20k adding the deck, you might increase the value of the property $10k-$15k but it is unlikely that you will get the full $20k. Basically, don't build a deck to make money, build the deck for your enjoyment while you live there. If you are going to be there 10yrs and lose $5k on the deck, that's not so bad if you got a lot of enjoyment out of it.

The only exception I could see....or that I have heard anyone in the business cite, would be if you had a really spectacular view that was really unique or incredible.

This is just one man's opinion on the internet, so take it for what it is worth....