Deck building costs?

Any thoughts on how much might it cost to build a deck on the roof of a first story space that juts out? The space seems ripe for it, it just needs the wooden floor, a rail of some sort and to be done legally, i.e. with all the city’s approvals and fees. The space is about 20 x 6. Any ballpark guesses would help.
Thanks!

By henrystreet |