§ 3105.10 When Certificate of Occupancy is Required
   (a)   Housing Certificates. Nothing contained in this chapter shall be deemed to require the issuance of a Certificate of Occupancy by the Commissioner of Building for any building or structure for which a Certificate of Occupancy has been issued or is required to be issued by the Commissioner of Housing under the authority of the Codified Ordinances or other applicable law or regulation.
   (b)   New Premises. No new building or other structure or part thereof shall be occupied and no previously unused premises shall be used or occupied until after the Commissioner of Building has issued a Certificate of Occupancy therefor.
   (c)   Change in Use or Occupancy; Additions, Extensions or Alterations.
      (1)   Whenever there is a change in the use or occupancy of a building or other structure or premises or part thereof which new use or occupancy results in reclassification of the building or other structure or premises or part thereof, under a different occupancy or use classification of the Zoning Code of the City, OBBC Chapter 4101:2-3, and or this Building Code, such building or other structure or premises shall not be used or occupied until a Certificate of Occupancy therefor is issued by the Commissioner.
      (2)   Whenever a building or other structure for which a Certificate of Occupancy has not been previously issued is enlarged or altered, the use or occupancy of such building or other structure, if not discontinued while work was done, shall not be continued for more than thirty (30) days after completion of the work, and if vacated while work was done, such building or other structure shall not be used or occupied, until a Certificate of Occupancy is issued by the Commissioner.