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  • CHAPTER3
    PROVISIONS FOR ALL COMPLIANCE METHODS

    SECTION301
    ADMINISTRATION

    301.1 General.

    The repair, alteration, change of occupancy, addition or relocation of all existing buildings shall comply with one of the methods listed in Sections 301.1.1 through 301.1.3 as selected by the applicant. Sections 301.1.1 through 301.1.3 shall not be applied in combination with each other. Where this code requires consideration of the seismic force-resisting system of an existing building subject to repair, alteration, change of occupancy, addition or relocation of existing buildings, the seismic evaluation and design shall be based on Section 301.1.4 regardless of which compliance method is used.

    Exception: Subject to the approval of the code official, alterations complying with the laws in existence at the time the building or the affected portion of the building was built shall be considered in compliance with the provisions of this code unless the building is undergoing more than a limited structural alteration as defined in Section 907.4.4. New structural members added as part of the alteration shall comply with the International Building Code. Alterations of existing buildings in flood hazard areas shall comply with Section 701.3.

    301.1.1 Prescriptive compliance method.

    Repairs, alterations, additions and changes of occupancy complying with Chapter 4 of this code in buildings complying with the International Fire Code shall be considered in compliance with the provisions of this code.

    301.1.2 Work area compliance method.

    Repairs, alterations, additions, changes in occupancy and relocated buildings complying with the applicable requirements of Chapters 5 through 13 of this code shall be considered in compliance with the provisions of this code.

    301.1.3 Performance compliance method.

    Repairs, alterations, additions, changes in occupancy and relocated buildings complying with Chapter 14 of this code shall be considered in compliance with the provisions of this code.

    [BS]301.1.4 Seismic evaluation and design procedures.

    The seismic evaluation and design shall be based on the procedures specified in the International Building Code or ASCE 41. The procedures contained in Appendix A of this code shall be permitted to be used as specified in Section 301.1.4.2.

    [BS]301.1.4.1 Compliance with International Building Code-level seismic forces.

    Where compliance with the seismic design provisions of the International Building Code is required, the criteria shall be in accordance with one of the following:

    1. 1.One-hundred percent of the values in the International Building Code. Where the existing seismic force-resisting system is a type that can be designated as “Ordinary,” values of R, Ω0 and Cd used for analysis in accordance with Chapter 16 of the International Building Code shall be those specified for structural systems classified as “Ordinary” in accordance with Table 12.2-1 of ASCE 7, unless it can be demonstrated that the structural system will provide performance equivalent to that of a “Detailed,” “Intermediate” or “Special” system.

    2. 2.ASCE 41, using a Tier 3 procedure and the two-level performance objective in Table 301.1.4.1 for the applicable risk category.

    [BS] TABLE 301.1.4.1

    PERFORMANCE OBJECTIVES FOR USE IN ASCE 41 FOR COMPLIANCE WITH INTERNATIONAL BUILDING CODE-LEVEL SEISMIC FORCES

    RISK CATEGORY(Based on IBC Table 1604.5)STRUCTURAL PERFORMANCE LEVEL FOR USEWITH BSE-1N EARTHQUAKE HAZARD LEVELSTRUCTURAL PERFORMANCE LEVEL FOR USEWITH BSE-2N EARTHQUAKE HAZARD LEVEL
    ILife Safety (S-3)Collapse Prevention (S-5)
    IILife Safety (S-3)Collapse Prevention (S-5)
    IIIDamage Control (S-2)Limited Safety (S-4)
    IVImmediate Occupancy (S-1)Life Safety (S-3)

    [BS]301.1.4.2 Compliance with reduced International Building Code-level seismic forces.

    Where seismic evaluation and design is permitted to meet reduced International Building Code seismic force levels, the criteria used shall be in accordance with one of the following:

    1. 1.The International Building Code using 75 percent of the prescribed forces. Values of R, Ω0 and Cd used for analysis shall be as specified in Section 301.1.4.1 of this code.

    2. 2.Structures or portions of structures that comply with the requirements of the applicable chapter in Appendix A as specified in Items 2.1 through 2.5 and subject to the limitations of the respective Appendix A chapters shall be deemed to comply with this section.

      1. 2.1.The seismic evaluation and design of unreinforced masonry bearing wall buildings in Risk Category I or II are permitted to be based on the procedures specified in Appendix Chapter A1.

      2. 2.2.Seismic evaluation and design of the wall anchorage system in reinforced concrete and reinforced masonry wall buildings with flexible diaphragms in Risk Category I or II are permitted to be based on the procedures specified in Chapter A2.

      3. 2.3.Seismic evaluation and design of cripple walls and sill plate anchorage in residential buildings of light-frame wood construction in Risk Category I or II are permitted to be based on the procedures specified in Chapter A3.

      4. 2.4.Seismic evaluation and design of soft, weak, or open-front wall conditions in multiunit residential buildings of wood construction in Risk Category I or II are permitted to be based on the procedures specified in Chapter A4.

      5. 2.5.Seismic evaluation and design of concrete buildings assigned to Risk Category I, II or III are permitted to be based on the procedures specified in Chapter A5.

    3. 3.ASCE 41, using the performance objective in Table 301.1.4.2 for the applicable risk category.

    [BS] TABLE 301.1.4.2

    PERFORMANCE OBJECTIVES FOR USE IN ASCE 41 FOR COMPLIANCE WITH REDUCED INTERNATIONAL BUILDING CODE-LEVEL SEISMIC FORCES

    RISK CATEGORY(Based on IBC Table 1604.5)STRUCTURAL PERFORMANCE LEVEL FOR USE WITH BSE-1E EARTHQUAKE HAZARD LEVEL
    ILife Safety (S-3)
    IILife Safety (S-3)
    IIIDamage Control (S-2). See Note a
    IVImmediate Occupancy (S-1)
    1. a.Tier 1 evaluation at the Damage Control performance level shall use the Tier 1 Life Safety checklists and Tier 1 Quick Check provisions midway between those specified for Life Safety and Immediate Occupancy performance.