Skip to content

Chapter 16A — STRUCTURAL DESIGN

Section 1617A — MODIFICATIONS TO ASCE 7

2025 California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-07-29 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

1617A.1 General.

The text of ASCE 7 shall be modified as indicated in Sections 1617A.1.1 through 1617A.1.41.

1617A.1.1 ASCE 7, Section 1.3. Modify ASCE 7, Section 1.3 by adding Section 1.3.8 as follows:

1.3.8 Structural design criteria. Where design is based on ASCE 7, Chapters 16, 17, 18 or 31, the seismic ground motion, wind tunnel test-based design recommendations, analysis and design methods, material assumptions, testing requirements and acceptance criteria shall be submitted to the enforcement agency as an alternative system.

[DSA-SS] Peer review requirements in Section 322 of the California Existing Building Code shall apply to design reviews required by ASCE 7, Chapters 17, 18, 31 and ASCE 49.

[OSHPD 1 & 4] Peer review requirements in Section 1617A.1.41 of this code shall apply to design reviews required by ASCE 7, Chap- ters 17 and 18.

1617A.1.2 ASCE 7, Section 11.1.3. Replace last paragraph of ASCE 7, Section 11.1.3, by the following:

Non-building structures similar to buildings shall be designed and detailed in accordance with Chapter 12.

1617A.1.3 Reserved.

1617A.1.4 ASCE 7, Table 12.2-1. Modify ASCE 7, Table 12.2-1 as follows:

A. BEARING WALL SYSTEMS

6. Intermediate Precast Shear Walls —Not permitted by OSHPD.

18 . Light-framed walls with shear panels of all other materials —Not permitted by OSHPD and DSA-SS.

B. BUILDING FRAME SYSTEMS

  1. Steel ordinary concentrically braced frames— Not permitted by OSHPD.

9 . Intermediate Precast Shear Walls —Not permitted by OSHPD.

25 . Light-framed walls with shear panels of all other materials —Not permitted by OSHPD and DSA-SS.

27 . Special steel plate shear wall —Not permitted by OSHPD.

16A-36 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

C . MOMENT-RESISTING FRAME SYSTEMS

  1. Steel special truss moment frames —Not permitted by OSHPD.

  2. Steel intermediate moment frames —Not permitted by OSHPD except for single-story canopies and independent covered walkways where R, C d and Ω 0 = 1.5 and the roof dead load is less than 20 psf.

  3. Steel ordinary moment frames —Not permitted by OSHPD except for single-story canopies and independent covered walk- ways where R, C d and Ω 0 = 1.5 and the roof dead load is less than 20 psf.

  4. Cold-formed steel–special bolted moment frame —Not permitted by DSA-SS and OSHPD.

G. CANTILEVER COLUMN SYSTEMS DETAILED TO CONFORM WITH THE REQUIREMENTS FOR:

  1. Steel special cantilever column systems —Not permitted by OSHPD except for single-story canopies and independent covered walkways where R, C d and Ω 0 = 1.5 and roof dead load is less than 20 psf.

3. Special reinforced concrete moment frames—Not permitted by OSHPD.

Exceptions: 1. Systems listed in this section can be used as an alternative system when preapproved by the enforcement agency. 2. Rooftop or other supported structures not exceeding two stories in height and 10 percent of the total structure weight can use the systems in this section when designed as components per ASCE 7, Chapter 13. 3. Systems listed in this section can be used for seismically isolated buildings, when permitted by ASCE 7, Section 17.2.5.4.

1617A.1.5 Reserved.

1617A.1.6 Reserved.

1617A.1.7 ASCE 7, Section 12.2.5.6.1 [DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.

1617A.1.8 ASCE 7, Section 12.2.5.7.1 [DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.

1617A.1.9 ASCE 7, Section 12.2.5.7.2 [DSA-SS] The exception after the first paragraph is not permitted by DSA-SS.

1617A.1.10 ASCE 7, Section 12.3.3.1. Replace ASCE 7, Section 12.3.3.1 by the following:

12.3.3.1 Prohibited vertical irregularities for Seismic Design Categories D through F. Structures assigned to Seismic Design Category D, E or F that have vertical irregularities Type 1b, 4a or 4b of Table 12.3-2 shall not be permitted.

Exception: Structures assigned to Seismic Design Category D, E or F that have vertical irregularity Type 4a shall be permitted where the story lateral strength is not less than 80% of that in the story above.

1617A.1.11 ASCE 7, Section 12.7.2. Modify ASCE 7, Section 12.7.2, by adding Item 7 to read as follows: 7. Where buildings provide lateral support for walls retaining earth, and the exterior grades on opposite sides of the building differ by more than 6 feet (1829 mm), the load combination of the seismic increment of earth pressure due to earthquake acting on the higher side, as determined by a geotechnical engineer qualified in soils engineering plus the difference in earth pressures shall be added to the lateral forces provided in this section.

1617A.1.12 ASCE 7, Section 12.10.2.1. Replace Exception to ASCE 7, Section 12.10.2.1 by the following:

Exception: In light-frame structures or portions thereof braced entirely by wood light-frame shear walls, collector elements and their connections, including connections to vertical elements, need only be designed to resist forces using the load combinations of Section 2.3.6 with seismic forces determined in accordance with Section 12.10.1.1.

1617A.1.13 ASCE 7, Section 12.13.5.2. Modify ASCE 7, Section 12.13.5.2 by the following:

Replace last sentence by the following: When vertical nominal strength (upward or downward) is determined by approved in-situ prototype testing program, resistance factor ( φ ) shall be permitted to be 0.75 ( φ = 0.75).

1617A.1.14 Reserved.

1617A.1.15 ASCE 7, Section 12.13.1. Modify ASCE 7, Section 12.13.1 by adding Section 12.13.1.1 as follows:

12.13.1.1 Foundations and superstructure-to-foundation connections. The foundation shall be capable of transmitting the design base shear and the overturning forces from the structure into the supporting soil. Stability against overturning and sliding shall be in accordance with Section 1605A.1.1.

In addition, the foundation and the connection of the superstructure elements to the foundation shall have the strength to resist, in addition to gravity loads, the lesser of the following seismic loads: 1. The strength of the superstructure elements. 2. The maximum forces that can be delivered to the foundation in a fully yielded structural system. 3. Forces from the load combinations with overstrength factor in accordance with ASCE 7, Section 12.4.3.1.

Exceptions: 1. Where referenced standards specify the use of higher design loads. 2. When it can be demonstrated that inelastic deformation of the foundation and superstructure-to-foundation connec- tion will not result in a weak story or cause collapse of the structure. 3. Where seismic force-resisting system consists of light framed walls with shear panels, unless the reference standard specifies the use of higher design loads.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

Where the computation of the seismic overturning moment is by the equivalent lateral-force method or the modal analysis method, reduction in overturning moment permitted by section 12.13.4 of ASCE 7 may be used.

Where moment resistance is assumed at the base of the superstructure elements, the rotation and flexural deformation of the foundation as well as deformation of the superstructure-to-foundation connection shall be considered in the drift and deforma- tion compatibility analyses.

1617A.1.16 ASCE 7, Section 12.13.9.2. Modify ASCE 7, Section 12.13.9.2 by adding the following sentence at the end of the exception:

Seismic load effects determined in accordance with Section 12.4 need not be considered in this check.

1617A.1.17 ASCE 7, Section 13.1.3. [OSHPD 1 & 4] Modify ASCE 7, Section 13.1.3 by the following: All nonstructural components shall have a component importance factor, I p , equal to 1.5. Exception: Hospital buildings rated SPC-1 and SPC-2 not providing services/systems, utilities or access/egress to general acute care buildings designated as SPC 3 or higher in accordance with Chapter 6 of the California Administrative Code, shall be permit- ted to use component importance factor, I p , as given in ASCE 7, Section 13.1.3. 1617A.1.18 ASCE 7, Section 13.1.4. Replace ASCE 7, Section 13.1.4, with the following:

nd SPC-2 not providing services/systems, utilities or access/egress to general acute_ care buildings designated as SPC 3 or higher in accordance with Chapter 6 of the California Administrative Code, shall be permit- ted to use component importance factor, I p , as given in ASCE 7, Section 13.1.3. 1617A.1.18 ASCE 7, Section 13.1.4. Replace ASCE 7, Section 13.1.4, with the following:

13.1.4 . Nonstructural component and equipment support and attachment requirements: The following nonstructural compo- nents and equipment shall be anchored in accordance with this section. Design and detailing shall be in accordance with Chapter 13 except as modified by this section. 1. Fixed Equipment: Equipment shall be anchored if it is directly attached to the building utility services such as electricity, gas or water. For the purposes of this requirement, “directly attached” shall include all electrical connections except plugs for 110/220-volt receptacles having a flexible cable/cord. Equipment that is connected to the building plumbing system with a shut-off valve in proximity to the equipment shall not be considered as directly attached provided the inside diameter of the pipe/tubing is less than [1] / 2 inch (12.7 mm). 2. Movable Equipment: Equipment is subject to the same requirement as fixed equipment, but is permitted to be anchored by re-attachable anchors or restraints in a manner approved by the enforcement agency. Utilities and services at the equipment shall have flexible connections to allow for necessary movement. 3. [OSHPD 1, 2, 4 & 5] Mobile Equipment: Equipment heavier than 400 pounds (181.4 kg) that has a center of mass located 4 feet (1219 mm) or more above the adjacent floor or roof level that directly support the equipment shall be restrained in a manner approved by the enforcement agency when stored and not in use, unless the equipment is stored in an equipment storage room.

[DSA-SS] Mobile Equipment: Equipment heavier than 400 pounds (181.4 kg) or has a center of mass located 4 feet (1219 mm) or more above the adjacent floor or roof level that directly supports the equipment shall be restrained in a manner approved by the enforcement agency. Mobile equipment shall be restrained when not in use and is stored, unless the equipment is stored in a storage room that does not house hazardous materials or any facility systems or fixed equip- ment that can be affected by mobile equipment lacking restraint. 4. [OSHPD 1, 2, 4 & 5] Countertop Equipment: Countertop equipment shall be subject to the same anchorage or restraint requirements for fixed, movable, mobile or other equipment, as applicable.

ess the_ equipment is stored in a storage room that does not house hazardous materials or any facility systems or fixed equip- ment that can be affected by mobile equipment lacking restraint. 4. [OSHPD 1, 2, 4 & 5] Countertop Equipment: Countertop equipment shall be subject to the same anchorage or restraint requirements for fixed, movable, mobile or other equipment, as applicable.

[DSA-SS] Countertop Equipment: Countertop equipment shall be subject to the same anchorage or restraint require- ments for fixed or movable equipment, as applicable. Countertop equipment shall also be subject to the same requirements as mobile or other equipment if weight of equipment is greater than 100 pounds (45 kg) and has a center of mass located 4 feet (1219 mm) or more above the adjacent floor level or if equipment could fall and block a required means of egress. 5. [OSHPD 1, 2, 4 & 5] Temporary Equipment: Equipment for uses greater than 30 days but less than or equal to 180 days and where this section requires supports and attachments, the following shall apply: a. Seismic design for supports and attachments for temporary equipment shall meet the requirements of Chapter 13; however, the calculated F p may be reduced by 50 percent. It is acceptable to use ballasts for seismic bracing supports and attachments and to limit the design criteria to overturning unless directly or indirectly supported by the building structure.

b. Wind design speeds may be reduced as prescribed in ASCE 37-14 or other standard approved by OSHPD. c. Temporary piping, conductors and ductwork shall be supported. Seismic design for supports and attachments of temporary piping, conductors and ductwork is not required. 6. [OSHPD 1, 2, 4 & 5] Interim Equipment: a. Seismic design for supports and attachments for interim equipment shall meet the requirements of Chapter 13 with the following modifications; 1) The calculated F p used in the design may be reduced by 50 percent. 2) It is accept- able to use ballasts for seismic or wind bracing supports and attachments and limit the design to overturning only without the consideration of sliding, unless directly or indirectly supported by the building structure. 3) Anticipated duration of use must be specified. b. Wind design speeds may be reduced as prescribed in ASCE 37-14 or other standard approved by OSHPD. c. Piping, conductors and ductwork shall be supported. Seismic design for supports and attachments of piping, conductors and ductwork is not required.

16A-38 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

7. Other Equipment: Equipment shall be anchored where any of the following apply: a. [OSHPD 1, 2, 4 & 5] Essential to hospital operations and weight of equipment is greater than 100 pounds (45 kg).

[DSA-SS] Weight of equipment is greater than 100 pounds (45 kg) and essential to operations for emergency preparedness, communications and operations centers, and other facilities required for emergency response of state-owned essential services buildings as defined in the California Administrative Code (Title 24, Part 1, CCR) Section 4-207 and all structures required for their continuous operation or access/egress. b. [OSHPD 1, 2, 4 & 5] Could fall within the patient care vicinity as defined in Article 517.2 of the California Electrical Code.

c. Could fall and block a required means of egress. d. [OSHPD 1, 2, 4 & 5] Weight of equipment is greater than 400 pounds (181.4 kg). e. [DSA-SS] Weight of equipment is greater than 400 pounds (181.4 kg) or center of mass is located greater than 4 feet (1219 mm) above the finished floor or roof level that directly supports the component.

[OSHPD 1, 2, 4 & 5] Weight of equipment is greater than 200 pounds (90 kg) and center of mass located greater than 4 feet (1219 mm) measured from the finished floor.

8. Equipment with hazardous contents. 9. Other architectural, mechanical and electrical components stated in Chapter 13. [DSA-SS] Cabinets shall be restrained in a manner approved by the enforcement agency if they could fall and block a required means of egress. 10. Wall-, Roof- or Floor-Hung Equipment: Seismic design and seismic details shall be provided for wall-, roof- or floor- hung nonstructural components and equipment when the component weighs more than 20 pounds (9 kg) or, in the case of a distribution system, 5 pounds per foot (73 N/m).

[OSHPD 1, 2, 4 & 5] Exemptions:

1. Furniture except storage cabinets as noted in Table 13.5-1. 2. Nonstructural components and equipment, that are attached to the building, provided that the component weighs 20 pounds (9 kg) or less or, in the case of a distribution system, 5 pounds per foot (73 N/m) or less. Seismic design and seis- mic details need not be provided. 3. Seismic design need not be provided for discrete architectural, mechanical and electrical components and equipment that are attached to the building and anchorage is detailed on the construction documents, provided that the compo- nent weighs 400 pounds (181.4 kg) or less, and the center of mass is located 4 feet (1219 mm) or less above the adjacent floor or roof level that directly support the component and flexible connections are provided between the component and associated ductwork, piping and conduit where required.

o the building and anchorage is detailed on the construction documents, provided that the compo-_ nent weighs 400 pounds (181.4 kg) or less, and the center of mass is located 4 feet (1219 mm) or less above the adjacent floor or roof level that directly support the component and flexible connections are provided between the component and associated ductwork, piping and conduit where required.

[DSA-SS] Exemptions: The following nonstructural components are exempt from the requirements of ASCE 7, Chapter 13: 1. Furniture except storage cabinets as noted in Table 13.5-1. 2. Nonstructural components and equipment that are positively attached to the structure, provided that the component weighs 20 pounds (9 kg) or less. 3. Discrete architectural, mechanical and electrical components and equipment that are positively attached to the structure, provided that the component weighs 400 pounds (181.4 kg) or less, and the center of mass is located 4 feet (1219 mm) or less above the adjacent floor or roof level that directly supports the component, flexible connections are provided between the component and associated ductwork, piping and conduit where required, and the component importance factor, I p , is equal to 1.0. 1617A.1.19 ASCE 7, Section 13.4 Replace ASCE 7, Sections 13.4.2.3, with the following:

13.4.2.3 Prequalified post-installed anchors and specialty inserts in concrete and masonry.

Post-installed anchors, post-installed reinforcing bars and specialty inserts in concrete that are pre-qualified for seismic appli- cations in accordance with ACI 355.2, ACI 355.4, ICC-ES AC193, ICC-ES AC232, ICC-ES AC308 or ICC-ES AC446 shall be permitted. Post-installed anchors in masonry shall be pre-qualified for seismic applications in accordance with ICC-ES AC01, AC58 or AC106.

Note: The removal and resetting of post-installed mechanical anchors are prohibited by ACI 318 Section 17.1.3.

1617A.1.20 ASCE 7, Section 13.4.5 Modify ASCE 7, Section 13.4.5 by adding Section 13.4.5.1 as follows:

13.4.5.1 Power actuated fasteners. Power actuated fasteners qualified in accordance with ICC ES AC 70 shall be deemed to satisfy the requirements of Section 13.4.5.

Power actuated fasteners shall be permitted in seismic shear for components exempt from permit requirements by Section 1617A.1.18 of this code and for interior non-bearing non-shear wall partitions only. Power actuated fastener shall not be used to anchor seismic bracing, exterior cladding or curtain wall systems.

Exception: Power actuated fasteners in steel to steel connections prequalified for seismic application by cyclic tests in accor- dance with ICC ES AC 70 shall be permitted for seismic design.

1617A.1.21 ASCE 7, Section 13.5.6.2. Modify ASCE 7, Section 13.5.6.2 by the following exception added to the end of Section 13.5.6.2.2 and by adding Section 13.5.6.2.3 as follows:

Exception to Section 13.5.8.1 shall not be used in accordance with ASTM E580 Section 5.5.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

13.5.6.2.3 Modification to ASTM E580. Modify ASTM E580 by the following: 1. Exitways. Lay-in ceiling assemblies in exitways shall be installed with a main runner or cross runner surrounding all sides of each piece of tile, board or panel and each light fixture or grille. A cross runner that supports another cross runner shall be considered as a main runner for the purpose of structural classification. Splices or intersections of such runners shall be attached with through connectors such as pop rivets, screws, pins, plates with end tabs or other approved connectors. Lateral force diagonal bracing may be omitted in the short or transverse direction of exitways, not exceeding 8 feet wide, when perimeter support in accordance with ASTM E580 Sections 5.2.2 and 5.2.3 is provided and the perimeter wall laterally supporting the ceiling in the short or transverse direction is designed to carry the ceiling lateral forces. The connections between the ceiling grid, wall angle and the wall shall be designed to resist the ceiling lateral forces. 2. Corridors and lobbies. Expansion joints shall be provided in the ceiling at intersections of corridors and at junctions of corridors and lobbies or other similar areas.

3. Lay-in panels. Metal panels and panels weighing more than [1] / 2 pounds per square foot (24 N/m [2] ) other than acoustical tiles shall be positively attached to the ceiling suspension runners. 4. Lateral force bracing. Lateral force bracing is required for all ceiling areas except that they shall be permitted to be omitted in rooms with floor areas up to 144 square feet when perimeter support in accordance with ASTM E580, Sections 5.2.2 and 5.2.3, are provided and perimeter walls are designed to carry the ceiling lateral forces. The connections between the ceiling grid, wall angle and the wall shall be designed to resist the ceiling lateral forces. Horizontal restraint point spacing shall be justified by analysis or test and shall not exceed a spacing of 12 feet by 12 feet. Bracing wires shall be secured with four tight twists in 1 [1] / 2 inches, or an approved alternate connection. 5. Ceiling support and bracing wires shall be spaced a minimum of 6 inches from all pipes, ducts, conduits and equipment that are not braced for horizontal forces, unless approved otherwise by the building official. 6. [OSHPD 1 & 4] Acoustical tile or lay-in panel ceiling grids constructed of aluminum shall have the hanger spacing at 2 feet on center each way and total ceiling weight of such systems, W p , shall not exceed 2 psf. 1617A.1.22 ASCE 7, Section 13.5.7. [OSHPD 1 & 4] Modify ASCE 7, Section 13.5.7, by the following:

All access floors shall be special access floors in accordance with Section 13.5.7.2, except for raised roof or exterior floor paver systems.

1617A.1.23 ASCE 7, Section 13.6.2.1. [OSHPD 1 & 4] Modify ASCE 7 Section 13.6.2.1 by adding the following to the end of the section:

Use of this section shall be considered as an alternative system. Alternatively, HVACR systems shall require special seismic certifica- tion in accordance with Section 1705A.14.3 of this code.

1617A.1.24 ASCE 7, Section 13.6.5. Replace ASCE 7, Section 13.6.5 as follows:

13.6.5 Distribution Systems: Conduit, Cable Tray and Raceways. Cable trays and raceways shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Conduit equal to or greater than 2.5 inches (64 mm) trade size and attached to panels, cabinets or other equipment subject to seismic relative displacement, D pI, shall be provided with flexible connections or designed for seismic forces and seismic relative displacements as required in Section 13.3.

Exceptions:

  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for raceways where flexible connections or other assemblies are provided between the cable tray or raceway and associated components to accommodate the relative displacement, where the cable tray or raceway is positively attached to the structure, and one of the following apply: a. Trapeze assemblies with [3] / 8 inch (10 mm) or [1] / 2 inch (13-mm) in diameter rod hangers not exceeding 12 inches (305 mm) in length from the conduit, cable tray or raceway support point to the connection at the supporting structure are used to support the cable tray or raceway, and the total weight supported by any single trapeze is 100 pounds (445 N) or less; or b . The conduit, cable tray or raceway is supported by individual rod hangers [3] / 8 inch (10 mm) or [1] / 2 inch (13 mm) in diameter, and each hanger in the raceway run is 12 inches (305 mm) or less in length from the conduit, cable tray or raceway support point connection to the supporting structure, and the total weight supported by any single rod is 50 pounds (220 N) or less.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for conduit, regardless of the value of I p, where the conduit is less than 2.5 inches (64 mm) trade size. Design for the displacements across seismic joints shall be required for conduit, cable trays and raceways with I p = 1.5 without consideration of conduit size.

1617A.1.25 ASCE 7, Section 13.6.6. Replace ASCE 7, Section 13.6.6 with the following:

13.6.6 Distribution Systems: Duct Systems . HVACR and other duct systems shall be designed for seismic forces and seismic relative displacements as required in Section 13.3.

Exceptions: The following exceptions pertain to ductwork not designed to carry toxic, highly toxic or flammable gases or not used for smoke control:

  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for duct systems where flexible connections or other assemblies are provided to accommodate the relative displacement between

16A-40 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

the duct system and associated components, the duct system is positively attached to the structure, and where one of the following apply: a. Trapeze assemblies with [3] / 8 -inch (10 mm) or [1] / 2 -inch (13 mm) diameter rod hangers not exceeding 12 inches (305 mm) in length from the duct support point to the connection at the supporting structure are used to support duct, and the total weight supported by any single trapeze is less than 10 lb/ft (146 N/m) and 100 pounds or less; or b. The duct is supported by individual rod hangers [3] / 8 inch (10 mm) or [1] / 2 inch (13 mm) in diameter, and each hanger in the duct run is 12 inches (305 mm) or less in length from the duct support point to the connection at the supporting structure, and the total weight supported by any single rod is 50 pounds (220 N) or less. 2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required where provisions are made to avoid impact with other ducts or mechanical components or to protect the ducts in the event of such impact, the distribution system is positively attached to the structure; and HVACR ducts have a cross-sectional area of less than 6 square feet (0.557 m [2] ) and weigh 20 lb/ft (292 N/m) or less.

Components that are installed in line with the duct system and have an operating weight greater than 75 pounds (334 N), such as fans, terminal units, heat exchangers and humidifiers, shall be supported and laterally braced independent of the duct system, and such braces shall meet the force requirements of Section 13.3.1. Components that are installed in line with the duct system, have an operating weight of 75 pounds (334 N) or less, such as small terminal units, dampers, louvers and diffusers, and are otherwise not independently braced shall be positively attached with mechanical fasteners to the rigid duct on both sides. Piping and conduit attached to in-line equipment shall be provided with adequate flexibility to accommodate the seismic relative displacements of Section 13.3.2.

1617A.1.26 ASCE 7, Section 13.6.7.3. Replace ASCE 7, Section 13.6.7.3 with the following:

13.6.7.3 Additional Provisions for Piping and Tubing Systems. A) Design for the seismic forces of Section 13.3 shall not be required for piping systems where flexible connections, expansion loops or other assemblies are provided to accommodate the relative displacement between component and piping, where the piping system is positively attached to the structure, and where any of the following conditions apply:

  1. Trapeze assemblies are supported by [3] / 8 -inch (10 mm) or [1] / 2 -inch (13 mm) diameter rod hangers not exceeding 12 inches (305 mm) in length from the pipe support point to the connection at the supporting structure, and no single pipe exceeds the diameter limits set forth in item 2b below or 2 inches (50 mm) where I p is greater than 1.0 and the total weight supported by any single trapeze is 100 pounds (445 N) or less; or 2. Piping is supported by rod hangers and provisions are made to avoid impact with other structural or nonstructural components or to protect the piping in the event of such impact; or pipes are supported by individual rod hangers [3] / 8 inch (10 mm) or [1] / 2 inch (13 mm) in diameter, where each hanger in the pipe run is 12 inches (305 mm) or less in length from the pipe support point to the connection at the supporting structure, and the total weight supported by any single hanger is 50 pounds (220 N) or less. In addition, the following limitations on the size of piping shall be observed: a. In structures assigned to Seismic Design Category D, E or F where I p is greater than 1.0, the nominal pipe size shall be 1 inch (25 mm) or less. b. In structures assigned to Seismic Design Category D, E or F where I p = 1.0, the nominal pipe size shall be 3 inches (80 mm) or less. 3. Pneumatic tube systems supported with trapeze assemblies using [3] / 8 inch (10 mm) in diameter rod hangers not exceeding 12 inches (305 mm) in length from the tube support point to the connection at the supporting structure and the total weight supported by any single trapeze is 100 pounds (445 N) or less. 4. Pneumatic tube systems supported by individual rod hangers [3] / 8 inch (10 mm) or [1] / 2 inch (13 mm) in diameter, and each hanger in the run is 12 inches (305 mm) or less in length from the tube support point to the connection at the supporting structure, and the total weight supported by any single rod is 50 pounds (220 N) or less. B) Flexible connections in piping required in Section 13.6.7.3 are not required where pipe is rigidly attached to the same floor or wall that provides vertical and lateral support for the equipment, or to a fixture. C) Flexible connections in piping are required at seismic separation joints and shall be detailed to accommodate the seis- mic relative displacements at connections.

1617A.1.27 ASCE 7, Section 13.6.11.1. Modify ASCE 7, Section 13.6.11.1, by adding Section 13.6.11.1.1 as follows:

13.6.11.1.1 Elevators guide rail support. The design of guide rail support-bracket fastenings and the supporting structural fram- ing shall use the weight of the counterweight or maximum weight of the car plus not less than 40 percent of its rated load. The seismic forces shall be assumed to be distributed one third to the top guiding members and two thirds to the bottom guiding members of cars and counterweights, unless other substantiating data are provided. In addition to the requirements of ASCE 7, Section 13.6.11.1, the minimum seismic forces shall be 0.5g allowable stress design load acting in any horizontal direction.

1617A.1.28 ASCE 7, Section 13.6.11.4. Replace ASCE 7, Section 13.6.11.4, as follows:

13.6.11.4 Retainer plates. Retainer plates are required at the top and bottom of the car and counterweight, except where safety devices acceptable to the enforcement agency are provided which meet all requirements of the retainer plates, including

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

full engagement of the machined portion of the rail. The design of the car, cab stabilizers, counterweight guide rails and counter- weight frames for seismic forces shall be based on the following requirements: 1. The seismic force shall be computed per the requirements of ASCE 7, Section 13.6.11.1. The minimum horizontal acceler- ation shall be 0.5g allowable stress design load for all buildings. 2. W p shall equal the weight of the counterweight or the maximum weight of the car plus not less than 40 percent of its rated load.

3. With the car or counterweight located in the most adverse position, the stress in the rail shall not exceed the limitations specified in these regulations, nor shall the deflection of the rail relative to its supports exceed the deflection listed below:

RAIL SIZE
(weight per foot of length, pounds)
WIDTH OF MACHINED SURFACE
(inches)
ALLOWABLE RAIL DEFLECTION
(inches)
8 11/4 0.20
11 11/2 0.30
12 13/4 0.40
15 131/32 0.50
181/2 131/32 0.50
221/2 2 0.50
30 21/4 0.50
For SI: 1 inch = 25 mm, 1 foot = 305 mm, 1 pound = 0.454 kg.
Note: Deflection limitations are given to maintain a consistent factor of safety against disengagement of retainer plates from the guide rails during an earthquake.

4. Where guide rails are continuous over supports and rail joints are within 2 feet (610 mm) of their supporting brackets, a simple span may be assumed. 5. The use of spreader brackets is allowed. 6. Cab stabilizers and counterweight frames shall be designed to withstand computed lateral load with a minimum hori- zontal acceleration of 0.5g allowable stress design load.

1617A.1.29 Reserved.

1617A.1.30 Reserved.

1617A.1.31 Reserved.

1617A.1.32 Reserved.

1617A.1.33 Reserved.

1617A.1.34 Reserved.

1617A.1.35 ASCE 7, Section 17.2.4.7. Modify ASCE 7, Section 17.2.4.7, by adding the following:

The effects of uplift shall be explicitly accounted for in the testing of the isolator units.

1617A.1.36 ASCE 7, Section 17.4. Modify ASCE 7, Section 17.4.2, by adding the following:

17.4.2.3 Linear procedures. Linear procedures shall not be used in Seismic Design Category E & F structures.

1617A.1.37 ASCE 7, Section 18.3. Replace exception to ASCE 7, Section 18.3 with the following:

Exception: If the calculated force in an element of the seismic force-resisting system does not exceed 1.5 times its nominal strength for the Risk-Targeted Maximum Considered Earthquake (MCE R ) the element is permitted to be modeled as linear. For this section, the MCE R response shall be based on largest response due to a single ground motion and not the average response of suite of ground motions.

1617A.1.38 ASCE 7, Section 20.3. [OSHPD 1 & 4] Modify ASCE 7 Section 20.3 by the following: Use of this section for new buildings with ground floor area larger than 4,000 square feet (371 m [2] ) shall be considered as an alter- native system.

1617A.1.39 Earthquake Motion Measuring Instrumentation and Post-earthquake Structural Monitoring/Verification. [OSHPD 1 & 4] Modify ASCE 7 by the following:

Scope: For buildings with a seismic isolation system, a damping system or a lateral force-resisting system (LFRS) not listed in ASCE 7, Table 12.2-1, earthquake motion measuring instrumentation and monitoring shall be required. For buildings with welded steel moment frames constructed under a permit issued prior to October 25, 1994 post-earthquake verification shall be in accordance with this section.

Instrumentation: Earthquake monitoring instrumentation shall be installed in accordance with Section 104.2.3.8.

Monitoring: After every significant seismic event, where the ground shaking acceleration at the site exceeds 0.3g or the accelera- tion at any monitored building level exceeds 0.8g as measured by the seismic monitoring system in the building, the owner shall retain a structural engineer to make an inspection of the structural system. The inspection shall include viewing the performance of the building, reviewing the strong motion records, and a visual examination of the isolators, dampers and connections for dete-

16A-42 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

rioration, offset or physical damage. A report for each inspection, including conclusions on the continuing adequacy of the structural system, shall be submitted to the enforcement agency.

Verification: After every seismic event that generates ground motions specified in the California Administrative Code, Chapter 6, Section 4.2.0.1 or the damage indicators specified in the California Administrative Code, Chapter 6, Section 4.2.0.2 at a welded steel moment frame building constructed under a permit issued prior to October 25, 1994, the owner shall retain a structural engi- neer to perform detailed joint evaluations required to meet the following requirements: 1. A detailed joint evaluation program shall be submitted to the enforcement agency for approval prepared in accordance with the requirements of the California Administrative Code, Chapter 6, Section 4.2.0.3. 2. Upon approval of the joint evaluation program required by Item 1 above for the joint inspections, a project to perform the joint inspections, detailed in the program, shall be submitted and a building permit shall be obtained by the owner no later than 6 months from the date of occurrence of the seismic event.

Exception: Where the ground motions at the building site are less than 0.4g, the permit shall be obtained no later than 12 months from the date of occurrence of the seismic event.

3. A detailed joint evaluation report shall be submitted to the enforcement agency no later than 6 months of obtaining the building permit. The report shall document the findings from the inspections of the joints and include conclusions on the adequacy of the structural system. Where unsafe conditions are discovered, the provisions of Section 116 shall apply.

Where the detailed joint evaluation report is not submitted within the timeframes specified above, the building shall not be issued a building permit for any projects except for those for seismic compliance, maintenance and repair until the detailed joint evaluation work is complete.

1617A.1.40 Operational nonstructural performance level requirements. [OSHPD 1 & 4] New general acute care hospitals and new building(s) required for general acute care services shall satisfy Operational Nonstructural Performance Level (NPC-5) requirements.

Exception: A new building which is required for general acute care services that is added to an existing general acute care hospital and which has a building area of 4,000 square feet (371 m [2] ) or less, need not satisfy the NPC-5 requirements until the deadline speci- fied in California Administrative Code (Part 1, Title 24 CCR), Chapter 6.

Hospitals and buildings designed and constructed to the provisions of this code for new construction shall be deemed to satisfy Operational Nonstructural Performance Level (NPC-5) requirements when: 1. The facility has on-site supplies of water and holding tanks for sewage and liquid waste, sufficient to support 72 hours of emergency operations for the hospital or building, which are integrated into the building plumbing systems in accordance with the California Plumbing Code. 2. An on-site emergency system as defined in the California Electrical Code is incorporated into the building electrical system for critical care areas. Additionally, the system shall provide for radiological service and an onsite fuel supply for 72 hours of acute care operation.

Emergency and standby generators shall not be located below the higher of the Design Flood Elevation (DFE) or Base Flood Eleva- tion (BFE) plus two feet (BFE + 2 ft.) or 500 year flood elevation, whichever is higher, and shall be located at an elevation close to grade for easy accessibility from outside for maintenance.

1617A.1.41 Peer Review Requirements. [OSHPD 1, 1R, 2 & 5] 1. General. Independent peer review is an objective technical review by knowledgeable reviewer(s) experienced in structural design, analysis and performance issues involved. The reviewer(s) shall examine the available information on the condition of the building, basic engineering concept employed and recommendations for action. Exception: OSHPD may perform the work of peer review when qualified staff is available. 2. Timing of Independent Review. The independent reviewer (s) shall be selected prior to initiation of substantial portion of the design and analysis work that is to be reviewed, and review shall start as soon as practical and sufficient information defining the project is available. 3. Qualifications and Terms of Employment. The reviewer shall be independent from the design and construction team. 3.1. The reviewer(s) shall have no other involvement in the project before, during or after the review, except in a review capacity. 3.2. The reviewer shall be selected and paid by owner and shall have technical expertise similar to the project being reviewed, as determined by enforcement agent. 3.3. The reviewer (in case of review team, the chair) shall be a California-licensed structural engineer who is familiar with technical issues and regulations governing the work to be reviewed. 3.4. The reviewer shall serve through completion of the project and shall not be terminated except for failure to perform the duties specified herein. Such termination shall be in writing with copies to enforcement agent, owner and the engineer of record. When a reviewer is terminated or resigns, a qualified replacement shall be appointed within 10 working days or a timeframe mutually agreed to by the Owner, Registered Design Professional (RDP) and the Office. 4. Scope of Review. Review activities shall include, where appropriate, available construction documents, design criteria, obser- vation of the condition of structure, all new and original inspection reports, including methods of sampling, analyses prepared by the engineer of record and consultants, and the new, retrofit or repair design. Review shall include consideration of the proposed design approach, method, materials and details.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

STRUCTURAL DESIGN

5. Reports. The reviewer(s) shall prepare a written report to the owner and responsible enforcement agent that covers all aspect of the review performed including conclusions reached by the reviewer. Report shall be issued after the schematic phase, during design development, and at the completion of construction documents, but prior to their issuance of permit. Such report shall include, at the minimum, statement of the following: a. Scope of engineering design peer review with limitations defined. b. The status of the project documents at each review stage. c. Ability of selected materials and framing systems to meet the performance criteria with given loads and configuration. d. Degree of structural system redundancy and the deformation compatibility among structural and nonstructural elements.

e. Basic constructability of the new, retrofit or repair system. f. Other recommendation that will be appropriate for the specific project. g. Presentation of the conclusions of the reviewer identifying any areas that need further review, investigation and/or clarification.

h. Recommendations.

16A-44 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

CHAPTER 17 – SPECIAL INSPECTIONS AND TESTS

(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

Adopting agency BSC BSC-
CG
SFM HCD DSA OSHPD BSCC DPH AGR DWR CEC CA SL SLC
Adopting agency BSC BSC-
CG
SFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 6 6 6 6 6 6 6 6 6
Adopt entire chapter X X
Adopt entire chapter as
amended (amended
sections listed below)
X X X X X X
Adopt only those sections
that are listed below
X
Chapter / Section
1701 X
1701.1.1 X X X
1701.1.2 X X X
1701.1.3 X X X
1702 X
1703 X
1703.4 X X X
1704.2 X X X X X
1704.2.3 X X X
1704.2.4 X X X
1704.2.5.1 X X X
1704.3.2 X X X
1705.1 X
1705.2.1 X X X
1705.2.2 X X X
1705.2.3 X X X
1705.2.4.1 X X X
1705.2.5.1 X X X
1705.2.7 X X X
1705.2.8 X X X
1705.3 X X X X
Table 1705.3 X X X X
1705.3.3 X X X
1705.3.3.1 X X X
1705.3.4 X X X
1705.3.5 X X X
1705.3.6 X X X
1705.3.7 X X X
1705.3.8 X X X
1705.3.9 X X X
1705.3.9.1 X X X
1705.3.9.2 X X X
1705.4 X X X
1705.4.1 X X X
1705.4.1.1 X X X
1705.5.3 X X X X
Table 1705.5.3 X X X X
1705.5.4 X X X
1705.5.5 X X X
1705.5.6 X
1705.5.7 X X X
1705.6.1 X X X

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

CHAPTER 17 – SPECIAL INSPECTIONS AND TESTS—continued

Adopting agency BSC BSC-
CG
SFM HCD DSA OSHPD BSCC DPH AGR DWR CEC CA SL SLC
Adopting agency BSC BSC-
CG
SFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 6 6 6 6 6 6 6 6 6
Adopt entire chapter X X
Adopt entire chapter as
amended (amended
sections listed below)
X X X X X X
Adopt only those sections
that are listed below
X
Chapter / Section
1705.7.1 X X X
1705.12.1 X
1705.12.2 X
1705.13.1.1 X X X
1705.13.1.2 X X X
1705.13.2 X
1705.13.3 X
1705.14.1.1 X X X
1705.14.1.2 X X X
1705.14.2 X X X
1705.14.3.1 X X X
1705.15 X
1705.16 X
1705.18 X X X X
1705.19_ –_1705.20 X
1707.1 X X X
1710 X X X

The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

17-2 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

Get a plain-English answer with a citation back to this text.

Ask AI about this code
Contents — 2025 California Building Code (Title 24, Part 2)
2025 California Building Code (Title 24, Part 2)
  1. Chapter 1 — ADMINISTRATION
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  4. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  5. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  6. Chapter 6 — TYPES OF CONSTRUCTION
  7. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  8. Chapter 7A — MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR W…
  9. Chapter 8 — INTERIOR FINISHES
  10. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  11. Chapter 10 — MEANS OF EGRESS
  12. Chapter 11 — RESERVED
  13. Chapter 11A — HOUSING ACCESSIBILITY
  14. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  15. Chapter 12 — INTERIOR ENVIRONMENT
  16. Chapter 13 — ENERGY EFFICIENCY
  17. Chapter 14 — EXTERIOR WALLS
  18. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  19. Chapter 16 — STRUCTURAL DESIGN
  20. Chapter 16A — STRUCTURAL DESIGN
  21. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  22. Chapter 17A — SPECIAL INSPECTIONS AND TESTS
  23. Chapter 18 — SOILS AND FOUNDATIONS
  24. Chapter 18A — SOILS AND FOUNDATIONS
  25. Chapter 19 — CONCRETE
  26. Chapter 19A — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 21A — MASONRY
  30. Chapter 22 — STEEL
  31. Chapter 22A — STEEL
  32. Chapter 23 — WOOD
  33. Chapter 24 — GLASS AND GLAZING
  34. Chapter 25 — GYPSUM PANEL PRODUCTS AND PLASTER
  35. Chapter 26 — PLASTIC
  36. Chapter 27 — ELECTRICAL
  37. Chapter 28 — MECHANICAL SYSTEMS
  38. Chapter 29 — PLUMBING SYSTEMS
  39. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  40. Chapter 31 — SPECIAL CONSTRUCTION
  41. Chapter 31A — SYSTEMS FOR WINDOW CLEANING OR EXTERIOR BUILDING…
  42. Chapter 31B — PUBLIC POOLS
  43. Chapter 31C — RADIATION
  44. Chapter 31D — FOOD ESTABLISHMENTS
  45. Chapter 31F — MARINE OIL TERMINALS
  46. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  47. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  48. Chapter 34 — RESERVED
  49. Chapter 35 — REFERENCED STANDARDS
  50. Appendix A — EMPLOYEE QUALIFICATIONS
  51. Appendix B — BOARD OF APPEALS
  52. Appendix C — GROUP U—AGRICULTURAL BUILDINGS
  53. Appendix D — FIRE DISTRICTS
  54. Appendix E — RESERVED
  55. Appendix F — RODENTPROOFING
  56. Appendix G — FLOOD-RESISTANT CONSTRUCTION
  57. Appendix H — SIGNS
  58. Appendix I — PATIO COVERS
  59. Appendix J — GRADING
  60. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES PROTECTED B…
  61. Appendix L — EARTHQUAKE RECORDING INSTRUMENTATION
  62. Appendix M — TSUNAMI-GENERATED FLOOD HAZARDS
  63. Appendix N — REPLICABLE BUILDINGS
  64. Appendix O — PERFORMANCE-BASED APPLICATION
  65. Appendix P — SLEEPING LOFTS
  66. Appendix Q — EMERGENCY HOUSING

GoCodebook provides public access, search, citation, multilingual explanation, and practical interpretation of legally adopted building regulations. It is not a substitute for the official ICC or California code publications.