I don't see any mention of a change of occupancy./QUOTE]The OP referenced the 2012 IEBC as a possible code. The IEBC is very specific about what constitutes a "Change of Occupancy"
CHAPTER 10
CHANGE OF OCCUPANCY
SECTION 1001
GENERAL
1001.1 Scope.
The provisions of this chapter shall apply where a change of occupancy occurs, as defined in Section 202, including:
1. Where the occupancy classification is not changed; or
2. Where there is a change in occupancy classification or the occupancy group designation changes.
1001.2 Change in occupancy with no change of occupancy classification.
A change in occupancy, as defined in Section 202, with no change of occupancy classification shall not be made to any structure that will subject the structure to any special provisions of the applicable International Codes, including the provisions of Sections 1002 through 1011, without the approval of the code official. A certificate of occupancy shall be issued where it has been determined that the requirements for the change in occupancy have been met.
1001.2.1 Repair and alteration with no change of occupancy classification.
Any repair or alteration work undertaken in connection with a change of occupancy that does not involve a change of occupancy classification shall conform to the applicable requirements for the work as classified in Chapter 4 and to the requirements of Sections 1002 through 1011.
Exception: As modified in Section 1205 for historic buildings.
1001.3 Change of occupancy classification.
Where the occupancy classification of a building changes, the provisions of Sections 1002 through 1012 shall apply. This includes a change of occupancy classification within a group as well as a change of occupancy classification from one group to a different group.
1001.3.1 Partial change of occupancy classification.
Where a portion of an existing building is changed to a new occupancy classification, Section 1012 shall apply.
1001.4 Certificate of occupancy required.
A certificate of occupancy shall be issued where a change of occupancy occurs that results in a different occupancy classification as determined by the International Building Code.