We're considering a new project and I'm not sure what we're getting into! Basically, we have a sunroom addition that was built by the previous owner by enclosing a porch (slab concrete foundation but I don't think footings). The roof is flat and sloped a little bit but not much, the roof over it is only a few years old and a good rubber roof. We're hoping to install a door in our second floor out to a balcony/deck on top of this roof.

We're not professionals, though my husband did work for years building decks, but never anything like this. It would only be about 8'X10' but I'm a little concerned about if it's feasible with building codes etc. and the best way to do it considering we need to have the deck be flat and since it would be over the rubber roof.

Any advice is appreciated!