R-1 Zoned Property rented as a Multi unit Dwelling Regulations

Hello, I'm new to real estate investing and I have a question.  Can a single family zoned property in South Florida be subdivided and rented as multiple units? Does the property need to be legally converted to a multi-unit dwelling prior to renting the multiple units? I see many R-1 zoned properties for sale claiming 2 and 3 rentable units with income.

Thank you for your help and feedback.