Citation from city about missing permits on single family home

[David He]

Hello fellow BP members, my wife and I just acquired our first multi-family home in the beautiful city of Greenville, SC. It's a single family home that has been converted to a duplex. However, the previous owners didn't obtain permits when they converted it. This would not normally be an issue, as many old houses in the right area don't have permits. But one of my relatives was so against our house purchase that she actually filed a complaint with the city, requesting them to check out the house for violations. 

My buyer agent assured me that he doesn't think much will come from it. But just less than a week after closing, one of my tenants received a citation from the city that said "Must purchase proper permits for conversion of single family dwelling to a duplex." We are required to correct the violation in 14 days and purchase proper permits and get approval through zoning for the made changes.

I've sent my contractor go talk to the city about the needed permits but I haven't heard back from him. Meanwhile my wife and I are are quite anxiety over this as some permits can cost over a thousand dollars and the verbiage mentioned permits(s), meaning there could be several.

I'm thinking the the worse case here is we'll spend $10k+ to get the permits needed, or we'll need to convert the property back to a single family. Is this correct? And if anyone has dealt with a similar situation when buying a multi-family home, could you please share what happened in your situation or any suggestions you have? 

Thanks!

David