What are the repercussions if I add a second unit to a zone RSA-5

[Vinh Nguyen]

Hello all, 

I am looking into a shell property that is zone for single family RSA-5. By the way it is designed, I can turn it into a duplex by adding a kitchen on the second floor. Question is what are the repercussions? Is it worth it? Do the benefits outweigh the risks? is it legal? I am new to the real estate investing, and I am just exploring my options. Please don't crucify me. Thank you!