A homestead under construction is not protected from creditors. Your property is not exempt under Florida Homestead law just because you intend to occupy the property sometime in the future.
Property reserved for a future residence cannot be homestead property until it is occupied. Future homes under construction are not exempt homestead properties. The homestead law requires you to reside in your home as your primary residence to have homestead protection.
If a civil judgment is recorded in the county where you own a house that you intend to occupy, or where you own a lot upon which you are building a future home, the recorded judgment will attach to your property. Subsequent occupancy of your home as a homestead will not erase the prerecorded judgment lien.
You should not purchase a homestead in any county where a creditor has previously recorded a judgment without careful planning, as the prior judgment may take precedence over your purchase and occupancy of a homestead in that county.