CEBC · California Existing Building Code
What CEBC modifications to ASCE 41 and special hospital provisions must I follow?
If you’re retrofitting or evaluating a hospital in California, the CEBC changes ASCE 41: use ASCE 41‑23 with CEBC edits in § 304A.3.6 (or ASCE 41‑13 only where CEBC allows), perform **Comprehensive** data collection and materials testing, meet hospital performance objectives in **§ 304A.3.4** (Immediate Occupancy and Life Safety as applicable), respect CEBC drift/SSI/materials rules, and note that unreinforced masonry is prohibited in general acute care hospitals.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Existing Building Code (CEBC) modifies ASCE 41 procedures and sets special hospital performance objectives. In short: for rehabilitation designed to ASCE 41-23, follow the CEBC modifications in § 304A.3.6; for ASCE 41-13 use the CEBC modifications in § 304A.3.5 (limited use); and the CEBC prescribes hospital performance objectives in § 304A.3.4. § 304A.3.4, § 304A.3.5.3, and § 304A.3.6 are the controlling provisions for hospital performance, data-collection and ASCE 41 changes.
The single most important rule: CEBC overrides and modifies ASCE 41 procedures for California projects — you must apply the CEBC text in § 304A.3.4, § 304A.3.5.3, and § 304A.3.6 (not plain ASCE 41) when designing hospital seismic evaluations and retrofits.
Requirements in detail
1) Which ASCE version and where it applies
- Use ASCE 41-23 for general applications except where the CEBC limits ASCE 41-13 to specific cases. Use ASCE 41-13 only for SPC‑2 and SPC‑4D per CEBC direction. § 304A.3.4 and its downstream clauses state this limit.
2) Hospital performance objectives (what the building must achieve)
For General Acute Care (GAC) hospital buildings and all structures required for their continuous operation or access/egress, the CEBC requires:
- Immediate Occupancy (S‑1) at BSE‑1N, and
- Life Safety (S‑3) at BSE‑2N,
- and nonstructural components must meet California Building Code new-construction requirements. See § 304A.3.4.1.
For other hospital building categories, the CEBC gives alternate performance objectives (see § 304A.3.4.2–.4.3 for incidental/minor pre‑1973 work and other hospital types).
3) Data collection and materials testing (important for modeling)
- CEBC raises the floor: data collection must be at the Comprehensive level for all structures, including those upgraded to SPC‑4D when following ASCE 41‑23 or ASCE 41‑13, except that Usual level is allowed for SPC‑2 or lower target objectives. Testing programs for material properties must be approved by the enforcement agent prior to testing. See § 304A.3.6.2 and § 304A.3.5.3.
4) Drift, acceptance criteria and material properties
Interstory drift limits: the CEBC modifies ASCE 41 drift acceptance so interstory drift shall not exceed the drift limits for Risk Category IV buildings in ASCE 7 Table 12.12‑1 under the applicable BSE (BSE‑1E or BSE‑1N). Larger drift can be permitted only with rational analysis and enforcement-agent approval. See § 304A.3.6.4 / § 304A.3.5.6.
Material properties: expected material properties must be based on materials tests — you cannot substitute expected values by multiplying lower‑bound values by assumed factors. See § 304A.3.6.5 / § 304A.3.5.7.
5) Ground motion, SSI and RRS limits
- The product RRS_bsa × RRS_e must be ≥ 0.7. Site‑specific response spectra accounting for soil‑structure interaction (SSI) shall not be taken as less than 80% (site‑specific per ASCE 7 §21.3) or 70% (design response / MCE_R options) of the spectral acceleration per ASCE 7 references. See § 304A.3.6.6 / § 304A.3.5.11.
6) Seismic earth pressure and below‑grade forces
- If grade difference from one side of the building to another exceeds one‑half story height, add the seismic increment of earth pressure to the gravity lateral earth pressure when evaluating overturning/sliding and below‑grade lateral resisting systems. See § 304A.3.6.7 / § 304A.3.5.12.
7) Special prohibitions for hospitals
- Unreinforced masonry walls and unreinforced infill walls/partitions are not permitted in General Acute Care (GAC) hospital buildings. See § 304A.3.6.8 and corresponding § 304A.3.5.15.
Decision‑relevant table
| Decision dimension | Required value / threshold | Code Reference |
|---|---|---|
| ASCE edition to use | ASCE 41‑23 generally; ASCE 41‑13 limited to SPC‑2 and SPC‑4D | § 304A.3.4 |
| Hospital structural objective (GAC) | Immediate Occupancy (S‑1) at BSE‑1N; Life Safety (S‑3) at BSE‑2N | § 304A.3.4.1 |
| Nonstructural requirement (GAC) | Meet CBC new‑construction nonstructural requirements | § 304A.3.4.1 |
| Data collection level | Comprehensive (exception: Usual for SPC‑2 or lower) | § 304A.3.6.2, § 304A.3.5.3 |
| Drift limits | Interstory drift ≤ ASCE 7 Table 12.12‑1 (Risk Cat. IV) for applicable BSE | § 304A.3.6.4 |
| Material properties | Must be based on materials tests (no assumed multiplier method) | § 304A.3.6.5, § 304A.3.5.7 |
| RRS product limit | RRS_bsa × RRS_e ≥ 0.7; SSI spectra not less than 80% or 70% per conditions | § 304A.3.6.6 |
| Prohibited construction in GAC | Unreinforced masonry prohibited | § 304A.3.6.8 |
Exceptions & special cases
The CEBC allows seismic evaluation of general acute care hospitals to be performed under Chapter 6 of the California Administrative Code (CAC) instead of ASCE 41 when that chapter’s provisions apply — this is explicitly called out as an exception in § 304A.3.6.1 and its ASCE 41‑13 analogue. Apply CAC Chapter 6 when required.
For SPC‑2 target objectives (lower performance targets), data collection at the Usual level is permitted instead of Comprehensive. See § 304A.3.5.3 / § 304A.3.6.2.
For nonconforming hospital upgrades to SPC‑4D and incidental/minor alterations, the CEBC provides alternate objective references (see § 304A.3.4.5 and related clauses). These are more specific and have their own test/documentation requirements.
Common mistakes
- Treating ASCE 41 text alone as sufficient: CEBC modifications are mandatory — do not omit the CEBC edits in § 304A.3.5/§ 304A.3.6.
- Skipping comprehensive data collection: designers sometimes use assumptions instead of testing; CEBC requires Comprehensive data collection for most targets and materials testing approval by the enforcement agent. Do not rely on assumed multipliers for material properties.
- Missing the hospital prohibition on unreinforced masonry: verify any URM walls are not part of a GAC hospital.
- Applying lower drift limits or acceptance criteria from the base ASCE 41 without checking the CEBC drift modification to align with Risk Category IV limits.
Worked example — small hospital wing upgrade (numbers)
Scenario: A two‑story ancillary wing of a GAC hospital will be retrofitted using ASCE 41‑23 to meet the CEBC hospital objectives.
Determine performance objectives per CEBC: For GAC, target Immediate Occupancy (S‑1) at BSE‑1N and Life Safety (S‑3) at BSE‑2N for the structure and CBC new‑construction requirements for nonstructural components (§ 304A.3.4.1).
Data collection: Because this is a hospital and the procedure is ASCE 41‑23, plan Comprehensive data collection and submit a materials testing program to the enforcement agent before sampling (per § 304A.3.6.2). Practically, expect concrete compressive tests, rebar tensile tests to ASTM A615, and in‑place concrete characterization.
Drift checks: Use ASCE 41 procedures but check interstory drift under BSE‑1N/BSE‑1E forces against ASCE 7 Table 12.12‑1 (Risk Category IV). If the computed drift is 0.8% but the ASCE 7 Table 12.12‑1 limit for the story is 0.6%, the retrofit must be designed to reduce drift (or justify a higher drift with rational analysis and enforcement agent approval) as required by § 304A.3.6.4.
RRS and SSI: Confirm the product RRS_bsa × RRS_e is ≥ 0.7. If your analysis gives RRS_bsa=0.9 and RRS_e=0.8, product=0.72 (acceptable). If you develop a site‑specific SSI spectrum, don’t reduce it to less than 80% of the site‑specific or 70% of the design/MCE_R options per § 304A.3.6.6.
Nonstructural anchors: Nonstructural components must meet CBC new‑construction rules for hospitals — ensure anchorage, restraint and functional testing for critical systems (per § 304A.3.4.1).
Related provisions
- § 304A.3.4 — Performance objectives for performance‑based methods (hospital objectives and how ASCE 41 is used).
- § 304A.3.5.3 — Data collection requirements / modifications to ASCE 41‑13 Section 6.2 (Comprehensive level requirement).
- § 304A.3.6 — Modifications to ASCE 41‑23 (full set of edits including data collection, drift, RRS/SSI and prohibitions).
- § 304A.3.6.2 — Specific wording on Comprehensive data collection for ASCE 41‑23.
- § 304A.3.6.4 — Drift acceptance and limits (ASCE 7 Risk Category IV reference).
- § 304A.3.6.6 — RRS and SSI floor limits and product requirement (≥ 0.7).
Code references
Grounded in the retrieved California Existing Building Code — click a citation to read the verbatim passage:
CEBC § 41-23. High relevance — show source text
Exception: Evaluation procedure of Article 11, Chapter 6 of the California Administrative Code shall be used for seismic evalua- tion of NPC 2, NPC 3, NPC 4 or NPC 4D and NPC 5, where specific procedure is not outlined in ASCE 41-23. Administrative and permitting provisions outlined in Article 11, Chapter 6 of the California Administrative Code shall apply.
304A.3.4.8 NPC-4 or NPC 4D and NPC-5 using ASCE 41-23: Nonstructural components for Operational Nonstructural Perfor- mance Level (N-A) in ASCE 41-23 Table 2-2 or NPC-4/NPC 4D shall satisfy the requirements of the California Building Code for new construction. Nonstructural components for NPC-5 shall satisfy Operational Performance Level N-A/NPC-4/NPC 4D and California Building Code Section 1617A.1.40 Items 1 & 2.
304A.3.5 Modifications to ASCE 41-13 for SPC-2 and SPC-4D. The text of ASCE 41-13 shall be modified as indicated in Sections 304A.3.5.1 through 304A.3.5.17.
304A.3.5.1 ASCE 41-13 Section 1.1. Modify ASCE 41-13 Section 1.1 with the following:
Seismic evaluations shall be performed for performance objective specified in Section 304A.3.4 of this code (CEBC) using proce- dure of this standard (ASCE 41) as follows:
1. Structural components shall be evaluated in accordance with Tier 3 systematic evaluations procedure in Chapter 6. 2. Nonstructural components shall be evaluated in accordance with Chapter 13.
Exception: For general acute care hospitals, seismic evaluation shall be permitted to be in accordance with Chapter 6 of the California Administrative Code (CAC) when required by provisions of that chapter.
304A.3.5.2 ASCE 41-13 Section 2.4 Seismic Hazard. Modify ASCE 41-13 Section 2.4 with the following:
Response spectra and acceleration time histories shall be constructed in accordance with 2016 California Building Code (CBC) Sections 1613A, 1616A, and 1803A.6 or equivalent provision in later versions of the CBC.
304A.3.5.3 ASCE 41-13 Section 6.2. Modify ASCE 41-13 Section 6.2 with the following:
Data Collection Requirements. The extent of data collection shall be at Comprehensive level for all structures, including struc- tures upgraded to SPC-4D. A testing program for materials properties shall be approved by the enforcement agent prior to
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commencement of material testing work. Previously approved material test results shall be permitted to be used to satisfy part of the comprehensive data collection requirements.
Exception: Data collection at Usual level shall be permitted for structures with SPC-2 or lower target performance objective.
CEBC § 501A.3.2 High relevance — show source text
501A.3.2 or_ 304A.3.4.5, but not a combination thereof, shall be considered to satisfy the requirements of SPC-4D. 1. Approval of construction documents based on building characterization in accordance with the California Administrative Code (CAC) Chapter 6 Section 2.1.2.1, material properties in accordance with the CAC Chapter 6 Section 2.1.2.2 and Section 304A.5.3 of this code, and a complete rational structural analysis shall be required. 2. Where the SPC-4D upgrade involves construction, a building permit prior to construction shall be required. 3. Where multiple building permits are used to upgrade a building to SPC-4D, a complete rational structural analysis to justify compliance with SPC-4D, for the building in its final configuration, shall be submitted as part of the construction documents submittal to the Office for the last project. 4. Where the SPC-4D upgrade involves construction, buildings shall be assigned to SPC-4D after all projects required for SPC- 4D are closed in compliance.
304A.3.4 Performance objectives of performance-based methods. Except for the modifications as set forth in Sections 304A.3.4, 304A.3.5 (for ASCE 41-13), and 304A.3.6 (for ASCE 41-23) of this code, all additions, alterations, repairs and seismic retrofit to existing structures or portions thereof shall be permitted to be designed in accordance with the provisions of ASCE 41-23.
Use of ASCE 41-13 shall be limited to SPC-2 and SPC-4D buildings only.
When load combinations which do not include seismic forces are required, the new building code provisions of the California Building Code shall be applicable. Required building performance objectives under ASCE 41-23 shall be as follows:
304A.3.4.1 For general acute care hospital buildings along with all structures required for their continuous operation or access/egress: 1. Immediate Occupancy (IO) Structural Performance Level (S-1) in accordance with ASCE 41-23 Table 2-1 at Basic Safety Earthquake 1N (BSE-1N) Seismic Hazard Level; and 2. Life Safety (LS) Structural Performance Level (S-3) in accordance with ASCE 41-23 Table 2-1 at Basic Safety Earthquake 2N (BSE-2N) Seismic Hazard Level; and
3. The nonstructural components shall satisfy the requirements of this code for new construction.
Exception: Performance objectives for upgrading nonconforming hospital buildings to SPC-4D and for incidental or minor alter- ations or repairs of SPC-4D buildings shall be in accordance with Section 304A.3.4.5 of this code.
CEBC § 319.8. High relevance — show source text
unless it can be demonstrated that_ reduced capacity meets the requirements of Section 319.8. 2. The lateral loading to or strength requirement of existing structural components is not increased beyond their capacity. 3. New structural components are detailed and connected to the existing structural components as required by the California Building Code. 4. New or relocated nonstructural components are detailed and connected to existing or new structural components as required by the California Building Code. 5. A dangerous condition is not created.
Use of ASCE 41 Tier 1 and Tier 2 deficiency only retrofit procedures are pre-approved for use where Section 317.3 does not require an
assessment.
319.12.1 State-owned buildings. [BSC] Voluntary modifications to lateral force-resisting systems conducted in accordance with Appendix A of this code and the referenced standards of the California Building Code shall be permitted.
319.12.1.1 Design documents. [BSC] When Section 319.12 is the basis for structural modifications, the approved design documents must clearly state the scope of the seismic modifications and the accepted criteria for the design. The approved design documents must clearly have the phrase “The seismic requirements of the California Existing Building Code have not been checked to determine if these structural modifications meet the full seismic evaluation and strengthening requirements of Sections 317-322: the modifications proposed are to a different seismic performance standard than would be required in Section 319 if they were not voluntary as allowed in Section 319.12.”
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319.12.2 Public schools and community colleges. [DSA-SS, DSA-SS/CC] When Section 319.12 is the basis for structural modifications, the approved design documents must clearly indicate the scope of modifications and the acceptance criteria for the design.
SECTION 320 [BSC, DSA-SS & DSA-SS/CC]—METHOD A
320.1 General. The retrofit design shall employ the Linear Static or Linear Dynamic Procedures of ASCE 41, Section 7.4.1 or 7.4.2, and comply with the applicable general requirements of ASCE 41, Chapters 6 and 7. The earthquake hazard level and performance level given specified in Section 317.5 for the building’s risk category shall be used. Structures shall be designed for seismic forces coming from any horizontal direction.
SECTION 321 [BSC, DSA-SS & DSA-SS/CC]—METHOD B
321.1 The existing or retrofitted structure shall be demonstrated to have the capability to sustain the deformation response due to the specified earthquake ground motions and meet the seismic performance requirements of Section 317. The registered design professional shall provide an evaluation of the response of the existing structure in its modified configuration and condition to the ground motions specified. If the building’s seismic performance is evaluated as satisfactory and the peer reviewer(s) and the enforcement agency concurs, then no further structural retrofit and/or repair of the lateral load-resisting system is required.
CEBC § 304A.3.5.13 High relevance — show source text
304A.3.5.13 ASCE 41-13 Section 10.7.1.1. Modify ASCE 41-13 Section 10.7.1.1 with the following:
Monolithic Reinforced Concrete Shear Walls and Wall Segments. For nonlinear procedures, shear walls or wall segments with axial loads greater than 0.35 Po shall be included in the model as primary elements with appropriate strength and stiffness degrading properties assigned to those components subject to the approval of the enforcement agent. For linear procedures, the effects of deformation compatibility shall be investigated using moment-curvature section analyses and cyclic testing results of similar components to determine whether strengthening is necessary to maintain the gravity load-carrying capacity of that component.
Horizontal wall segments or spandrels reinforced similar to vertical wall segments or piers shall be classified as wall segments, not shear wall coupling beams, in Tables 10-19 through 10-22.
304A.3.5.14 ASCE 41-13 Section 10.12.3 Modify ASCE 41-13 Section 10.12.3 as follows:
Exception: Component actions that are deformation controlled are permitted to use their expected strengths for the accep- tance criteria.
304A.3.5.15 ASCE 41-13 Section 11.1. Modify ASCE 41-13 Section 11.1 by the following:
Scope: Unreinforced masonry walls (including unreinforced infill walls) and partitions are not permitted for General Acute Care (GAC) hospital buildings.
304A.3.5.16 ASCE 41-13 Section 14.1. Modify ASCE 41-13 Section 14.1 by the following:
Scope: For buildings located in Seismic Design Category F, verification of the interstory lateral displacements, the strength adequacy of the seismic force-resisting system and anchorage to the foundation shall be accomplished using the Nonlinear Dynamic Procedure.
304A.3.5.17 ASCE 41-13 Chapter 15 and 16. Not permitted by OSHPD.
304A.3.6 Modifications to ASCE 41-23. The text of ASCE 41-23 shall be modified as indicated in Sections 304A.3.6.1 through 304A.3.6.9.
304A.3.6.1 ASCE 41-23 Section 2.1. Modify ASCE 41-23 Section 2.1 with the following:
Seismic evaluations shall be performed for performance objective specified in Section 304A.3.4 of this code (CEBC) using proce- dure of this standard (ASCE 41-23) as follows:
1. Structural components shall be evaluated in accordance with Tier 3 systematic evaluations procedure in Chapter 6.
2. Nonstructural components shall be evaluated in accordance with Chapter 13.
Exception: For general acute care hospitals, seismic evaluation shall be permitted to be in accordance with Chapter 6 of the California Administrative Code (CAC) when required by provisions of that chapter.
304A.3.6.2 ASCE 41-23 Section 6.2. Modify ASCE 41-23 Section 6.2 with the following:
CEBC § 304A.3.5.17 High relevance — show source text
Scope: For buildings located in Seismic Design Category F, verification of the interstory lateral displacements, the strength adequacy of the seismic force-resisting system and anchorage to the foundation shall be accomplished using the Nonlinear Dynamic Procedure.
304A.3.5.17 ASCE 41-13 Chapter 15 and 16. Not permitted by OSHPD.
304A.3.6 Modifications to ASCE 41-23. The text of ASCE 41-23 shall be modified as indicated in Sections 304A.3.6.1 through 304A.3.6.9.
304A.3.6.1 ASCE 41-23 Section 2.1. Modify ASCE 41-23 Section 2.1 with the following:
Seismic evaluations shall be performed for performance objective specified in Section 304A.3.4 of this code (CEBC) using proce- dure of this standard (ASCE 41-23) as follows:
1. Structural components shall be evaluated in accordance with Tier 3 systematic evaluations procedure in Chapter 6.
2. Nonstructural components shall be evaluated in accordance with Chapter 13.
Exception: For general acute care hospitals, seismic evaluation shall be permitted to be in accordance with Chapter 6 of the California Administrative Code (CAC) when required by provisions of that chapter.
304A.3.6.2 ASCE 41-23 Section 6.2. Modify ASCE 41-23 Section 6.2 with the following:
Data Collection Requirements. The extent of data collection shall be at Comprehensive level for all structures, including struc- tures upgraded to SPC-4D. A testing program for materials properties shall be approved by the enforcement agent prior to commencement of material testing work. Previously approved material test results shall be permitted to be used to satisfy part of the comprehensive data collection requirements.
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Tension testing of reinforcing bars shall be in accordance with ASTM A615. All test specimens shall be the full section of the bar as rolled (8-in. gage length) and shall not be reduced.
At test sample locations, structural members, slabs and walls shall be repaired to a state that is equivalent to their original condition.
For buildings built under an OSHPD permit based on the 1976 or later edition of the CBC, where materials properties are shown on design drawings and original materials test data are available, no materials testing shall be required when approved by the enforcement agent.
304A.3.6.3 ASCE 41-23 Section 7.2.9.1. Modify ASCE 41-23 Section 7.2.9.1 with the following:
For the evaluation of one-story light-framed walls with or without hold-downs, ASCE 41-23 Equation 7-6 is permitted to be used. If Equation 7-6 is satisfied, no further evaluation or retrofit of the existing hold-down, if any, is required. If Equation 7-6 is not _satisfied, hold-down shall be provided or retrofitted using ASCE 41-23 Equations 7-39 and 7-40.
CEBC § 7-6 High relevance — show source text
Alternatively, if Equation 7-6 is not satisfied and retrofit is not performed,_ the wall contribution to the lateral resisting system shall be ignored. For all other building type conditions, Equation 7-6 shall not be used.
304A.3.6.4 ASCE 41-23 Section 7.5.1. Modify ASCE 41-23 Section 7.5.1 with the following:
Acceptance Criteria – Drift Limitations. The interstory drift ratio shall not exceed the drift limits for Risk Category IV buildings in ASCE 7 Table 12.12-1 due to forces corresponding to BSE-1E or BSE-1N, as applicable.
Exception: Larger interstory drift ratios shall be permitted where justified by rational analysis that both structural and nonstructural elements can tolerate such drift and approved by the enforcement agent.
304A.3.6.5 ASCE 41-23 Section 7.5.1.4. Modify ASCE 41-23 Section 7.5.1.4 by the following:
Material Properties. Expected material properties are not permitted to be determined by multiplying lower bound values by the assumed factors specified in Chapters 8 through 12.
304A.3.6.6 ASCE 41-23 Section 8.6.1. Modify ASCE 41-23 Section 8.6.1 with the following:
The product of RRS bsa x RRS e shall be not less than 0.7.
The combined effect of kinematic interaction and foundation damping shall meet the following: 1. The site-specific response spectrum modified for soil-structure interaction effects shall not be taken as less than 80 percent of the spectral acceleration as determined from a site-specific response spectrum in accordance with ASCE 7 Section 21.3; or
2. The site-specific response spectrum modified for soil-structure interaction effects shall not be taken as less than 70 percent of the spectral acceleration as determined from the design response spectrum and M CER response spectrum in accordance with ASCE 7 Sections 11.4.5 and 11.4.6, respectively.
Exception: For the seismic retrofit of existing nonconforming buildings, design ground motion shall be consistent with performance objectives in Section 304A.3.4 of this code.
304A.3.6.7 ASCE 41-23 Section 8.7. Modify ASCE 41-23 Section 8.7 with the following:
Seismic Earth Pressure. Where the grade difference from one side of the building to another exceeds one-half story height, the seismic increment of earth pressure shall be added to the gravity lateral earth pressure to evaluate the building overturning and sliding stability and the lateral force-resisting system below grade in combination with the building seismic forces.
304A.3.6.8 ASCE 41-23 Section 11.1. Modify ASCE 41-23 Section 11.1 by the following:
Scope: Unreinforced masonry walls (including unreinforced infill walls) and partitions are not permitted for General Acute Care (GAC) hospital buildings.
304A.3.6.9 ASCE 41-23 Chapter 16 and 17. Not permitted by OSHPD.
CEBC § 11.4.5 High relevance — show source text
2. The site-specific response spectrum modified for soil-structure interaction effects shall not be taken as less than 70 percent of the spectral acceleration as determined from the design response spectrum and M CER response spectrum in accordance with ASCE 7 Sections 11.4.5 and 11.4.6, respectively.
Exception: For the seismic retrofit of existing nonconforming buildings, design ground motion shall be consistent with performance objectives in Section 304A.3.4 of this code.
304A.3.6.7 ASCE 41-23 Section 8.7. Modify ASCE 41-23 Section 8.7 with the following:
Seismic Earth Pressure. Where the grade difference from one side of the building to another exceeds one-half story height, the seismic increment of earth pressure shall be added to the gravity lateral earth pressure to evaluate the building overturning and sliding stability and the lateral force-resisting system below grade in combination with the building seismic forces.
304A.3.6.8 ASCE 41-23 Section 11.1. Modify ASCE 41-23 Section 11.1 by the following:
Scope: Unreinforced masonry walls (including unreinforced infill walls) and partitions are not permitted for General Acute Care (GAC) hospital buildings.
304A.3.6.9 ASCE 41-23 Chapter 16 and 17. Not permitted by OSHPD.
SECTION 305 A —IN-SITU LOAD TESTS
305 A .1 General. Where used, in-situ load tests shall be conducted in accordance with Section 1708 A of the California Building Code .
SECTION 306 A —ACCESSIBILITY FOR EXISTING BUILDINGS
306 A .1 Scope. Accessibility requirements for existing buildings shall comply with the California Building Code, Part 2, Volume 1, Chapter 11B.
SECTION 307 A —SMOKE ALARMS
Shall comply with the California Building Standards Code.
SECTION 308 A —CARBON MONOXIDE DETECTION
Shall comply with the California Building Standards Code.
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SECTION 309 A — RESERVED
SECTION 310A — COMPLIANCE ALTERNATIVES FOR SERVICES/SYSTEMS AND UTILITIES
310A.1 General. The provisions of this section are intended to maintain or increase the current degree of public safety, health and general welfare in existing buildings while permitting repair, alteration, addition and change of occupancy without requiring full compli- ance with California Building Code Chapters 2 through 33, or Sections 302A.3 and 502A through 506A, except where compliance with other provisions of this code is specifically required in this section.
CEBC § 304A.3.5.4 High relevance — show source text
Tension testing of reinforcing bars shall be in accordance with ASTM A615. All test specimens shall be the full section of the bar as rolled (8-in. gage length) and shall not be reduced.
At test sample locations, structural members, slabs and walls shall be repaired to a state that is equivalent to their original condition.
For buildings built under an OSHPD permit based on the 1976 or later edition of the CBC, where materials properties are shown on design drawings and original materials test data are available, no materials testing shall be required when approved by the enforcement agent.
304A.3.5.4 ASCE 41-13 Section 7.2.8.1. Modify ASCE 41-13 Section 7.2.8.1 with the following:
For the evaluation of one-story light-framed walls with or without hold-downs, ASCE 41-13 Equation 7-6 is permitted to be used. If Equation 7-6 is satisfied, no further evaluation or retrofit of the existing hold-down, if any, is required. If Equation 7-6 is not satisfied, hold-down shall be provided or retrofitted using ASCE 41-13 Equations 7-36 and 7-37. Equation 7-6 shall not be used to limit forces to other elements along the load path to the subject light-frame wall. Other elements, such as the diaphragm, collec- tor, shear wall, sill bolts, cripple wall, etc., shall be evaluated independently using ASCE 41-13 Equations 7-36 and 7-37 with the associated m or J factors listed under Chapter 12. Alternatively, if Equation 7-6 is not satisfied and retrofit is not performed, the wall contribution to the lateral resisting system shall be ignored. For all other building type conditions, Equation 7-6 shall not be used.
304A.3.5.5 ASCE 41-13 Section 7.3.2.1. Modify ASCE 41-13 Section 7.3.2.1 with the following:
Nonlinear Static Procedure. If higher mode effects are significant and building is taller than 75 feet above the base, the Nonlin- ear Dynamic Procedure shall be used.
304A.3.5.6 ASCE 41-13 Section 7.5.1. Modify ASCE 41-13 Section 7.5.1 with the following:
Acceptance Criteria – Drift Limitations. The interstory drift ratio shall not exceed the drift limits for Risk Category IV buildings in ASCE 7 Table 12.12-1 due to forces corresponding to BSE-1E or BSE-1N, as applicable.
Exception: Larger interstory drift ratios shall be permitted where justified by rational analysis that items identified in Chap- ter 6 Article 10 of the California Administrative Code can tolerate such drift and approved by the enforcement agent.
304A.3.5.7 ASCE 41-13 Section 7.5.1.4. Modify ASCE 41-13 Section 7.5.1.4 by the following:
Material Properties. Expected material properties are not permitted to be determined by multiplying lower bound values by the assumed factors specified in Chapters 8 through 12 and shall be based exclusively on materials tests.
CEBC § 1.5. High relevance — show source text
Exception: Components required for life-safety purposes after an earthquake, including emergency and standby power systems, mechanical smoke removal systems, fire protection sprinkler systems, fire alarm control panels and egress stairways shall have a component importance factor (I p ) of 1.5.
304A.3.1.2 Major structural alteration, additions or repairs. Major structural alterations, additions or repairs shall be in accor- dance with Section 304A.3.4.1 or 304A.3.4.3 as applicable.
304A.3.2 Seismic evaluation and retrofit of general acute care hospitals for compliance with the California Administrative Code, Chapter 6. Notwithstanding any other requirements of this code, existing general acute care hospitals shall comply with the seismic evaluation requirements specified in Chapter 6, of the California Administrative Code, when applicable. Seismic retrofit to comply with requirements specified in Chapter 6 of the California Administrative Code shall be permitted to be in accordance with these provisions. When load combinations which do not include seismic forces are required, the new building provisions of this code shall be applicable.
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304A.3.3 SPC-4D. Nonconforming hospital buildings satisfying the following requirements and one of Sections 501A.3.1, 501A.3.2 or 304A.3.4.5, but not a combination thereof, shall be considered to satisfy the requirements of SPC-4D. 1. Approval of construction documents based on building characterization in accordance with the California Administrative Code (CAC) Chapter 6 Section 2.1.2.1, material properties in accordance with the CAC Chapter 6 Section 2.1.2.2 and Section 304A.5.3 of this code, and a complete rational structural analysis shall be required. 2. Where the SPC-4D upgrade involves construction, a building permit prior to construction shall be required. 3. Where multiple building permits are used to upgrade a building to SPC-4D, a complete rational structural analysis to justify compliance with SPC-4D, for the building in its final configuration, shall be submitted as part of the construction documents submittal to the Office for the last project. 4. Where the SPC-4D upgrade involves construction, buildings shall be assigned to SPC-4D after all projects required for SPC- 4D are closed in compliance.
304A.3.4 Performance objectives of performance-based methods. Except for the modifications as set forth in Sections 304A.3.4, 304A.3.5 (for ASCE 41-13), and 304A.3.6 (for ASCE 41-23) of this code, all additions, alterations, repairs and seismic retrofit to existing structures or portions thereof shall be permitted to be designed in accordance with the provisions of ASCE 41-23.
Use of ASCE 41-13 shall be limited to SPC-2 and SPC-4D buildings only.
CEBC § 304A.3.5.2 High relevance — show source text
1. Structural components shall be evaluated in accordance with Tier 3 systematic evaluations procedure in Chapter 6. 2. Nonstructural components shall be evaluated in accordance with Chapter 13.
Exception: For general acute care hospitals, seismic evaluation shall be permitted to be in accordance with Chapter 6 of the California Administrative Code (CAC) when required by provisions of that chapter.
304A.3.5.2 ASCE 41-13 Section 2.4 Seismic Hazard. Modify ASCE 41-13 Section 2.4 with the following:
Response spectra and acceleration time histories shall be constructed in accordance with 2016 California Building Code (CBC) Sections 1613A, 1616A, and 1803A.6 or equivalent provision in later versions of the CBC.
304A.3.5.3 ASCE 41-13 Section 6.2. Modify ASCE 41-13 Section 6.2 with the following:
Data Collection Requirements. The extent of data collection shall be at Comprehensive level for all structures, including struc- tures upgraded to SPC-4D. A testing program for materials properties shall be approved by the enforcement agent prior to
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commencement of material testing work. Previously approved material test results shall be permitted to be used to satisfy part of the comprehensive data collection requirements.
Exception: Data collection at Usual level shall be permitted for structures with SPC-2 or lower target performance objective.
Tension testing of reinforcing bars shall be in accordance with ASTM A615. All test specimens shall be the full section of the bar as rolled (8-in. gage length) and shall not be reduced.
At test sample locations, structural members, slabs and walls shall be repaired to a state that is equivalent to their original condition.
For buildings built under an OSHPD permit based on the 1976 or later edition of the CBC, where materials properties are shown on design drawings and original materials test data are available, no materials testing shall be required when approved by the enforcement agent.
304A.3.5.4 ASCE 41-13 Section 7.2.8.1. Modify ASCE 41-13 Section 7.2.8.1 with the following:
For the evaluation of one-story light-framed walls with or without hold-downs, ASCE 41-13 Equation 7-6 is permitted to be used. If Equation 7-6 is satisfied, no further evaluation or retrofit of the existing hold-down, if any, is required. If Equation 7-6 is not satisfied, hold-down shall be provided or retrofitted using ASCE 41-13 Equations 7-36 and 7-37. Equation 7-6 shall not be used to limit forces to other elements along the load path to the subject light-frame wall. Other elements, such as the diaphragm, collec- tor, shear wall, sill bolts, cripple wall, etc., shall be evaluated independently using ASCE 41-13 Equations 7-36 and 7-37 with the _associated m or J factors listed under Chapter 12.
CEBC § 304A.3.5.11 High relevance — show source text
The evaluation of the foundation structural element shall be considered as force controlled in accordance with the material chapters using the bearing pressure distribution under the footing from the same method used for the soil bearing acceptance criteria.
304A.3.5.11 ASCE 41-13 Section 8.5.1. Modify ASCE 41-13 Section 8.5.1 with the following:
The product of RRS bsa x RRS e , shall not be less than 0.7.
The combined effect of kinematic interaction and foundation damping shall meet the following:
1. The site-specific response spectrum modified for soil-structure interaction effects shall not be taken as less than 80 percent of the spectral acceleration as determined from a site-specific response spectrum in accordance with ASCE 7 Section 21.3, or
2. The site-specific response spectrum modified for soil-structure interaction effects shall not be taken as less than 70 percent of the spectral acceleration as determined from the design response spectrum and MCE R response spectrum in accordance with ASCE 7 Sections 11.4.5 and 11.4.6, respectively.
Exception: For the seismic retrofit of existing nonconforming buildings, design ground motion shall be consistent with performance objectives in Section 304A.3.4.
304A.3.5.12 ASCE 41-13 Section 8.6. Modify ASCE 41-13 Section 8.6 with the following:
Seismic Earth Pressure. Where the grade difference from one side of the building to another exceeds one-half story height, the seismic increment of earth pressure shall be added to the gravity lateral earth pressure to evaluate the building overturning and sliding stability and the lateral force-resisting system below grade in combination with the building seismic forces.
304A.3.5.13 ASCE 41-13 Section 10.7.1.1. Modify ASCE 41-13 Section 10.7.1.1 with the following:
Monolithic Reinforced Concrete Shear Walls and Wall Segments. For nonlinear procedures, shear walls or wall segments with axial loads greater than 0.35 Po shall be included in the model as primary elements with appropriate strength and stiffness degrading properties assigned to those components subject to the approval of the enforcement agent. For linear procedures, the effects of deformation compatibility shall be investigated using moment-curvature section analyses and cyclic testing results of similar components to determine whether strengthening is necessary to maintain the gravity load-carrying capacity of that component.
Horizontal wall segments or spandrels reinforced similar to vertical wall segments or piers shall be classified as wall segments, not shear wall coupling beams, in Tables 10-19 through 10-22.
304A.3.5.14 ASCE 41-13 Section 10.12.3 Modify ASCE 41-13 Section 10.12.3 as follows:
Exception: Component actions that are deformation controlled are permitted to use their expected strengths for the accep- tance criteria.
304A.3.5.15 ASCE 41-13 Section 11.1. Modify ASCE 41-13 Section 11.1 by the following:
Scope: Unreinforced masonry walls (including unreinforced infill walls) and partitions are not permitted for General Acute Care (GAC) hospital buildings.
CEBC § 7-6 High relevance — show source text
Alternatively, if Equation 7-6 is not satisfied and retrofit is not performed, the_ wall contribution to the lateral resisting system shall be ignored. For all other building type conditions, Equation 7-6 shall not be used.
304A.3.5.5 ASCE 41-13 Section 7.3.2.1. Modify ASCE 41-13 Section 7.3.2.1 with the following:
Nonlinear Static Procedure. If higher mode effects are significant and building is taller than 75 feet above the base, the Nonlin- ear Dynamic Procedure shall be used.
304A.3.5.6 ASCE 41-13 Section 7.5.1. Modify ASCE 41-13 Section 7.5.1 with the following:
Acceptance Criteria – Drift Limitations. The interstory drift ratio shall not exceed the drift limits for Risk Category IV buildings in ASCE 7 Table 12.12-1 due to forces corresponding to BSE-1E or BSE-1N, as applicable.
Exception: Larger interstory drift ratios shall be permitted where justified by rational analysis that items identified in Chap- ter 6 Article 10 of the California Administrative Code can tolerate such drift and approved by the enforcement agent.
304A.3.5.7 ASCE 41-13 Section 7.5.1.4. Modify ASCE 41-13 Section 7.5.1.4 by the following:
Material Properties. Expected material properties are not permitted to be determined by multiplying lower bound values by the assumed factors specified in Chapters 8 through 12 and shall be based exclusively on materials tests.
304A.3.5.8 ASCE 41-13 Section 8.4. Modify ASCE 41-13 Section 8.4 with the following:
Foundation Strength and Stiffness. Foundation and soil strength shall be used to evaluate potential overturning, uplift and sliding for fixed base assumptions, and stiffness for flexible base assumptions, including deformations associated with those actions.
304A.3.5.9 ASCE 41-13 Section 8.4.1.1. Replace ASCE 41-13 Section 8.4.1.1 as follows:
Prescriptive Expected Capacities. Not permitted by OSHPD.
304A.3.5.10 ASCE 41-13 Section 8.4.2.3.2.1. Modify ASCE 41-13 Sections 8.4.2.3.2.1 and 8.4.2.3.2.2 as follows:
8.4.2.3.2.1 Alternatively, when seismic evaluation is performed for foundation after global analysis of the superstructure is complete, both overturning and axial seismic pseudo force demands are permitted to be divided by the m-factors above, provided the foundation is analyzed as a beam on Winkler springs (soil does not resist tension). The vertical spring stiffness _values may be determined either from Figure 8-2 or Equation 8-11, or as provided by the geotechnical engineer.
Frequently asked questions
What section do I cite on my plans to show I followed CEBC modifications to ASCE 41?
Cite the specific CEBC modification sections you applied (for example § 304A.3.6 for ASCE 41‑23 modifications and § 304A.3.4 for hospital performance objectives) and include the relevant ASCE 41 sections you modified per the CEBC text.
Can I use ASCE 41‑13 instead of ASCE 41‑23 for a hospital project?
ASCE 41‑13 use is limited by CEBC: it is permitted only for SPC‑2 and SPC‑4D buildings. For general use prefer ASCE 41‑23 and apply CEBC § 304A.3.6 modifications.
Is materials testing always required?
Yes — CEBC requires expected material properties to be based on materials tests and requires an approved testing program; prescriptive expected capacities are not permitted for many items. There are limited exceptions (e.g., previously approved test data under OSHPD drawings). See § 304A.3.6.5 / § 304A.3.5.7.
Are unreinforced masonry walls allowed in hospitals?
No. Unreinforced masonry walls and unreinforced infill walls/partitions are not permitted in General Acute Care hospitals under the CEBC modifications. § 304A.3.6.8 (and its ASCE 41‑13 analogue) prohibits them.
What if I want to use CAC Chapter 6 for a general acute care hospital evaluation?
The CEBC explicitly permits use of CAC Chapter 6 for general acute care hospitals when its provisions apply — that is an allowed exception to the ASCE 41 requirement; document and coordinate with the enforcement agency. See § 304A.3.6.1 and related text.
More in California Existing Building Code
- Administration and Definitions (Scope, enforcement, code official duties, definitions)
- Provisions for All Compliance Methods (general requirements that apply to all compliance options; Chapter 3 / 3A)
- Seismic retrofit and evaluation (Appendix A and seismic provisions/sections for evaluation and retrofit)
- Referenced Standards and Appendices (Chapter 16 and Appendices A–E, Resource A)
- Repairs (Chapter 4 — repair-specific rules for materials, means of egress, structural, MEP, etc.)
- Alterations — Level 1, Level 2, Level 3 (technical requirements for each alteration level; Chapters 7–9)
- Change of Occupancy and Additions (requirements for occupancy changes and additions; Chapters 10–11)
- Compliance Methods — Prescriptive, Work Area, Performance (Chapters 5, 6–11, 13)
- Relocated Buildings (requirements for buildings moved or relocated; Chapter 14)
- Construction Safeguards (site safety, means of egress and life-safety during construction; Chapter 15)
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