For the purposes of Article 11. (Division of Land), a conversion project is an existing building proposed for conversion to a condominium, stock cooperative, or community apartment through approval of a tract map or parcel map. For purposes of this definition, the term existing means that the building was constructed prior to 1945 or, where built after 1945, a Certificate of Occupancy was issued for the building prior to the time of map application. Conversion project includes residential conversion project, residential to commercial/industrial conversion project, and commercial/industrial to residential conversion project.