The provisions of Section 506 of IEBC are adopted by reference with the following modifications:
1. Revise Sections 506.1 and 506.1.1 to read:
"506.1 Compliance.
A change of occupancy shall not be made in any building unless that building is made to comply with the requirements of the Chicago Building Code for the use or occupancy. Changes of occupancy in a building or portion thereof shall be such that the existing building is not less complying with the provisions of this code than the existing building or structure was prior to the change. Where approved by the building official, changes of occupancy shall be permitted without complying with all of the requirements of this code for the new occupancy, provided that the new occupancy is no more hazardous than the existing occupancy in accordance with Tables 1011.4, 1011.5 and 1011.6.
Exception: The building need not be made to comply with Chapter 16 of the Chicago Building Code unless required by Section 506.4.
506.1.1 Change in the character of use.
A change of use or creation of an incidental use with no change of occupancy shall not be made to any structure that will subject the structure to any special provision of the applicable Chicago Construction Codes, without obtaining a permit from the building official to comply with the special provision. Compliance shall be only as necessary to meet the specific provision and is not intended to require the entire building be brought into compliance with requirements for new construction."
2. Delete Section 506.2.
3. Revise Section 506.4.1 to read:
"506.4.1 Live loads.
Structural elements carrying tributary live loads from an area with a change of occupancy shall satisfy the requirements of Section 1607 of the Chicago Building Code. Design live loads for areas of new occupancy shall be based on Section 1607 of the Chicago Building Code.
Exception: Structural elements whose demand-capacity ratio considering the change of occupancy is not more than 5 percent greater than the previous demand-capacity ratio."
4. Revise the exception to Section 506.4.2 to read:
"Exception: Where the floor area of the change of occupancy is less than 10 percent of the building area, compliance with this section is not required. The cumulative effect of occupancy changes over time shall be considered."
5. Revise Section 506.4.3, including its exceptions, to read:
"506.4.3 Seismic loads (seismic force-resisting system).
Where a change of occupancy results in a building being assigned to Risk Category IV, the building shall satisfy the requirements of Section 1613 of the Chicago Building Code for the new risk category using full seismic forces."
6. Revise Section 506.4.4 to read:
"506.4.4 Access to Risk Category IV.
Any structure that provides operational access to an adjacent structure assigned to Risk Category IV as the result of a change of occupancy shall itself satisfy the requirements of Sections 1608, 1609 and 1613 of the Chicago Building Code. For compliance with Section 1613, the full seismic forces shall be used. Where operational access to the Risk Category IV structure is less than 10 feet (3048 mm) from either an abutting property line or from another structure, access protection from potential falling debris shall be provided."