San Francisco County Municipal Code Ch. 5 Prescriptive

SECTION 501 – GENERAL SECTION 502 – ADDITIONS 502.7 Add the following section: 502.7 High-rise buildings. Any existing building or structure to which an addition is made which causes the building or structure to fall within the scope of San Francisco Building Code Section 403 shall comply with the provisions of that section. 502.8 Add the following section: 502.8 Horizontal additions. Horizontal additions shall meet the following requirements: When the cumulative area of horizontal additions, excluding basement additions, exceeds 30 percent of the area of the original building or structure, excluding basements, and the additions are structurally interconnected to, or not separated to comply with ASCE 7-22 Section 12.12.2, the entire structure shall comply with Section 304.4. SECTION 503 – ALTERATIONS 503.11 Revise this section as follows:

503.11 Substantial structural alteration. Where [ ← ] work involves a substantial structural alteration, the lateral load-resisting system of the altered building shall satisfy the requirements of Sections 1609 of the [ ← ] San Francisco Building Code and section 304.3.2 of this code. Where the building is assigned to Seismic Design Category D or F, supports and attachments for nonstructural components required to serve any portion of the building with a use included in Risk Category IV shall comply with Section 1613 of the [ ← ] San Francisco Building Code or shall comply with ASCE 41 using an objective of Position Retention nonstructural performance with the BSE-1E earthquake hazard level. Exceptions: 1. Buildings of Group R occupancy with not more than five dwelling or sleeping units used solely for residential purposes that are altered based on the conventional light-frame construction methods of the [ ← ] San Francisco Building Code. [ ← ]
2. Where the intended alteration involves structural components of the lowest story of a building and Section 506 does not apply, [ ← ] the lateral load-resisting system above that story need not comply with this section. SECTION 506 – CHANGE OF OCCUPANCY 506.5.3 Add the following sections: 506.5.3.1 Increase in Occupant Load. Where the occupant load of the entire building or structure is increased by more than 10 percent and by more than 100 persons as compared to the occupant load of the existing legal use or the use for which the building was originally permitted, the building shall comply with Section 304.3.2 for the reduced seismic criteria. 506.5.3.2 Group E. A building changing occupancy to an E occupancy, and is otherwise subject to Section 329, shall comply with Section 329. Add the following sections: SECTION 508 – MOVED STRUCTURES 508.1 Conformance. Structures moved into or within the jurisdiction shall comply with the provisions of the San Francisco Building Code for new structures. 508.2 Removal of Debris. Immediately after the building is moved and before it is occupied at the new site, the permittee must remove all debris and all walls and footings above grade at the site from which it has been moved, except where such walls provide support to adjacent buildings, structures or property. All excavated areas must be filled in or protected by substantial fences not less than 5 feet (1524 mm) in height. Add the following Chapter: