Yes, the Florida Building Code-Residential applies to the described project. Under the Residential Code as detached single family dwellings and use assumed property lines.
The Residential Code contains a definition for "Fire Separation Distance" #3 "to an imaginary line between two buildings on the same lot".
The scope in FRC R101.2 (and the FBC 101.2) indicate the use of the Residential Code for detached one and two family dwellings. If you read the definition of a "dwelling" and since none of the previous sections cited nor the FBC 310.5 mention anything about having to be on their own lot, therefore these units are in fact detached single family dwellings covered under the Residential Code.
