The provisions of Section 303 of IEBC are adopted by reference with the following modifications:
1. Revise Section 303.1 to read:
"303.1 Live loads.
Where an addition or alteration does not result in increased design live load, existing gravity load carrying structural elements shall be allowed to be evaluated and designed for live loads approved by the building official that are less than those required by Section 1607 of the Chicago Building Code. Any area approved for a reduced live load shall be posted with permanent placards indicating the approved live load. Where the addition or alteration results in increased design live load, the live load required by Section 1607 of the Chicago Building Code shall be used."
2. Revise Table 303.3.1 by replacing "IBC" with "CBC."
3. Revise Table 303.3.2 by replacing "IBC" with "CBC."
4. Revise Section 303.3.2 to read:
"303.3.2 Compliance with reduced seismic forces.
Where seismic evaluation and design is allowed to use reduced seismic forces, the criteria used shall be in accordance with one of the following:
1. The Chicago Building Code using 75 percent of the prescribed forces. Values of R, 0 and Cd used for analysis shall be as specified in Section 303.3.1 of this code.
2. [Reserved.]
3. ASCE 41, using the performance objective in Table 303.3.2 for the applicable risk category."
(Amend Coun. J. 7-24-19, p. 3646, § 40; Amend Coun. J. 2-19-20, p. 14473, Art. IV, § 4)