The following sections of Chapter 5 of the California Existing Building Code, as adopted by Chapter 18.01 hereof, are added, deleted, or amended as follows.
(Ord. 25-5, 11/25/2025)
Sections 503.7.1 and 503.7.2 are added to read as follows:
503.7.1 Additional anchorage provisions for concrete and reinforced masonry walls. Where an existing building’s structural system includes concrete or reinforced masonry walls with a flexible roof diaphragm, the existing roof-to-wall connections and sub-diaphragms shall be analyzed and upgraded as required by this section. The provisions of this section shall not exempt any building from the requirements of sections 503.7, 503.11, or 506.5.3. | |
Exceptions: | |
1. | The requirements of this section shall not apply to areas of the building which are under separate ownership from the area of addition or alteration. |
2. | The requirements of this section shall not apply to areas of the building which are leased and occupied separately from the area of addition or alteration. |
3. | The requirements of this section shall not apply where access to more than 50 percent of the existing roof structure is obstructed by existing framed ceilings, fire-rated assemblies, or other fixed elements which are not being removed or relocated as part of the proposed project. |
503.7.1.1 Additions. Where the area of an addition exceeds 25 percent of the original building area, the requirements of section 503.7.2 shall be met. | |
503.7.1.2 Additions and alterations. Where the combined area of an addition and alteration exceeds 50 percent of the original building area, the requirements of section 503.7.2 shall be met. | |
502.7.1.3 Alteration with a change in occupancy group. Where an alteration includes a change from occupancy group B, M, F, S or U to occupancy group A, E, H, I, L, or R as defined in the California Building Code and the altered area exceeds 50 percent of the building area, the requirements of section 503.7.2 shall be met. | |
503.7.2 Roof anchorage structural requirements. Where required by section 503.7.1, all roof-to-wall connections shall be capable of transferring the reduced seismic forces specified in section 304.3.2. Roof to wall anchorage connections shall extend into the diaphragm a distance to develop the force transferred into the diaphragm. Structural calculations and drawings shall be sealed and signed by a California licensed civil or structural engineer. | |
(Ord. 25-5, 11/25/2025)