My name is Carl Kabat and I'm a Realtor with Coldwell Banker Preferred. I have a contact at City Planning that could answer your question. Feel free to email me at:
Good news: Here's the site to go to - http://www.philaplanning.org/
Bad news: It's something you would have to ask them.
Zoning changes can be a lengthy process. Just do your homework and make sure everything is done properly. Complications can stall things for a long time.