Here is another example of business owners expanding their operation upward, when adjacent property isn't available. Although this is good for extra occupancy, especially in a restaurant or bars profitability, it provides for certain obstacles and dangers for firefighters.
As was brought-up (by Jake Rixner) in my previous post about "rear porches", these additions (roof top decks/patios) aren't likely built to code. In a lot of jurisdictions, a roof top deck/patio can't be visible from six feet (or below) off of the street level. Obviously in this photograph, it is clearly in violation of this. With that being said, the rest of the code has probably been disregarded as well. Whether its in violation of construction materials, points of egress, open flame (heaters, tiki torches), maximum occupancy, etc.
As responding firefighters to these types of additions, we must have a pre-determined plan on how to effectively get lines in-service, exposure problems (both horizontally, vertically and drop down to the original roof), where our best rescue and egress points will be, etc. The best way to do this will be to get out and survey your respective response area(s).
As building construction continues to progress and these types of additions become trendier, they will likely become common in single family residences and aforementioned establishments. Firefighters in the City of New York have experienced fires in these roof top additions for quite some time. Some time ago, an FDNY Firefighter (Officer) published a training article about this in their "WNYF" Magazine.