Adding a rooftop terrace or patio

[James Z.]

Hello all, we are thinking about adding a rooftop terrace or patio to the flat roof. We contacted the city building department, and were told it needs both zoning change and permit. We'd like to see if you have done rooftop terrace or patio to the flat roof before, and was it complicated and time consuming to: obtain zoning change and permit; and build a rooftop terrace or patio? It is in the SF bay area (CA). Any input is much appreciated!