zoning in Palm Beach County, FL

[Jim Hern]

Help please...I recently looked at two duplexes - both zoned R1D. However,  I see one has a Use Code "0800 multifamily < 10 units" and the other has a Use Code "0100 single family."  What is a Use Code and who determines that - City or County?  And if I want to buy the duplex with a

Use Code "0100 single family" and then rent it to two families - how do I ensure that I don't get in trouble? Do I (and can I) convert it to Use Code "0800 multifamily < 10 units"?

Thanks in advance!