# What are the key changes in Chapter 4 Special Detailed Requirements Based On Occupancy & Use of CBC 2025? Author: Lovekush Gangwar Author URL: https://www.meltplan.com/blogs/author/lovekush-gangwar Published: 2025-12-01 Category: Code Updates Category URL: https://www.meltplan.com/blogs/category/code-updates Meta Title: What are the key changes in Chapter 4 Special Detailed Requirements Based On Occupancy & Use of CBC 2025? Meta Description: A comprehensive breakdown of the major 2025 California Building Code Chapter 4 revisions, including new high-rise glazing rules, updated stair re-entry requirements, expanded atrium exceptions, rewritten I-2 care suite egress standards, new I-3 sallyport criteria, and broad hazardous materials updates. Includes expert insights and FAQs. Tags: buildingcodes Tag URLs: buildingcodes (https://www.meltplan.com/blogs/tag/buildingcodes) URL: https://www.meltplan.com/blogs/key-changes-in-chapter-4-special-detailed-requirements-based-on-occupancy-use-of-cbc-2025 Chapter 4 sees substantial changes, especially for **high-rise buildings, atriums, care suites in I-2 occupancies, hazardous materials, and special amusement areas**. The most significant changes include: - New **glass wall rules** for high-rise buildings - Revised **stairway re-entry door** operation requirements - Expanded **atrium enclosure** exceptions (especially for I-2/R-2.1) - New **vehicle sallyport** requirements for I-3 - Relocation of special amusement area alarm requirements - Significant rewrites for **care suite** egress and access rules - Updates throughout hazardous material sections ### Full Detailed Table Of All Changes  -  Chapter 4 SectionTopicDescription of ChangeImpact403.2.2.1Wall Assembly MaterialsReorganized requirements for interior wall structural impact resistance at shafts/stairways.Clarifies and standardizes high-rise wall assembly approvals.403.2.2.4Glass Walls in High-RisesNew criteria added.Allows innovative façade/atrium glazing with safety criteria.403.3.1Sprinkler RisersNow allows a single express riser for buildings under 420 ft.Reduces cost for mid-rise/high-rise projects.403.5.3Stairway Door OperationMandatory unlocking on power failure; fire alarm; FCC signal.Enhances firefighter access and life safety.404.6 Exception 5Atrium EnclosuresIn I-2 and R-2.1, 3-story atriums may omit fire barriers if smoke control accounts for adjoining spaces.Increased design flexibility in healthcare/residential care.404.10Exit Stairways in AtriumsNew condition: discharge must comply with §1928.1.Aligns atrium discharge with exit discharge rules.404.12Group I & R-2.1 Means of EgressEgress from treatment rooms may not pass through an atrium.Prevents unsafe reliance on atrium path for assisted-care egress.407.4.4.1Exit Access through Care Suites2022 mid-cycle amendment removed for CA; requirement struck.Deletes conflicting/overlapping CA amendment.407.4.4.3Corridor Access, Group I-2Completely rewritten; includes: max. 100 ft travel inside suite, limits on intervening rooms, sprinkler exceptions.Major redesign implications for I-2 patient care floors.408.13I-3 WindowsUpdated security glazing standards.Stronger break resistance standards for correctional facilities.408.16Vehicle Sallyports, I-3Requires NFPA 13 sprinklers + 2-hr fire barrier unless roof ≥50% open.Raises safety for secure prisoner transport.410.2.4Proscenium WallException allows new rated assemblies in Type I buildings.More flexibility for theaters/performing arts buildings.411.3Amusement Area DetectionDetection/alarm requirements moved from §907.12.1–§907.2.12.3.Consolidates amusement area rules for clarity.411.4.1Exit MarkingPhotoluminescent exit signs required.Modernizes visual egress cueing in dark ride spaces.411.6Flammable Decorative MaterialsCommissioned to §806 compliance.Improves consistency across chapters.414Hazardous MaterialsRevisions to tables and quantities.Must re-evaluate all hazmat storage designs.420.2Separation WallsClarifies walls between sleeping units & dwelling units must also be fire partitions.Ensures adequate vertical separation in multi-family.420.3Horizontal SeparationFloor assemblies separating sleeping from dwelling units must meet §711.Strengthens sound/fire separations.422.7Domestic Cooking in Ambulatory CareBuilding must be fully sprinklered; cooking areas must be fire-partitioned.Reduces common fire risk in healthcare kitchens.423.4.1 & 423.5.1Storm SheltersAdds design occupant capacity requirements.Aligns CA with ICC/NSSA storm shelter standards. ‍ ### Expert Commentary  -  Why Chapter 4 Is Influential #### 1\. Healthcare (I-2) sees major changes The rewritten care suite rules fundamentally impact: - Nurse station placement - Corridor access - Travel distances - Patient room access sequences Architects designing hospitals will need to revisit standard floor templates. #### 2\. Atrium flexibility increased Especially for medical and R-2.1 occupancies  -  a big benefit for designers wanting open, daylighted multistory spaces in care environments. #### 3\. High-rise and tall buildings get new glazing & stair door rules These are based on post-incident analyses and help ensure: - Firefighter re-entry - Reduced smoke-floor infiltration - Safer glass failure modes #### 4\. New sallyport rules Correctional facilities will see stricter requirements, particularly around fire spread in enclosed vehicle transfer zones. # FAQs ### 1\. What types of buildings are most affected by the 2025 Chapter 4 changes? The most impacted occupancies include **high-rise buildings**, **healthcare facilities (I-2)**, **residential care (R-2.1)**, **correctional facilities (I-3)**, and any building with **atriums** or **hazardous materials**. These groups see the largest revisions in egress, fire protection, glazing, and smoke control rules. ### 2\. What is the biggest change for healthcare projects? The **complete rewrite of care suite egress and corridor access requirements (§407.4.4.3)**. ‍ This change affects: - Maximum internal travel distances - Allowed intervening spaces - Access to corridors - Sprinkler and smoke control interactions Hospitals and medical designers will need to re-evaluate typical floor layouts and care suite configurations. ### 3\. How do the new high-rise glass wall rules affect design? Section **403.2.2.4** introduces new criteria for glass walls in high-rise buildings, allowing more innovative atrium and façade glazing while applying stricter safety and performance requirements. This enables design flexibility but requires earlier structural and fire-life-safety coordination. ### 4\. What changed regarding stair door re-entry in high-rises? Section **403.5.3** now requires stairway doors to unlock under: - Power failure - Fire alarm activation - Fire Command Center (FCC) signal This enhances firefighter access and prevents entrapment during emergencies. ### 5\. How did atrium design rules change? A major new exception allows **I-2 and R-2.1** buildings to omit certain fire barriers for 3-story atriums **if the smoke control system accounts for the adjoining spaces**. This enables more open, daylighted designs, especially in healthcare or assisted-living facilities. ### 6\. What’s new for correctional facility vehicle sallyports? Section **408.16** now requires: - NFPA 13 sprinklers - A **2-hour fire barrier** ‍ Unless the roof is at least **50% open to the outdoors**. This significantly increases fire protection requirements for enclosed transfer areas. ### 7\. Which amusement area rules were relocated? Detection and alarm rules moved from scattered locations in **907.2.12.1–907.2.12.3** into a unified location at **§411.3**, making amusement area compliance easier to interpret and enforce. ### 8\. Do the hazardous materials sections change significantly? Yes. Chapter 4’s hazmat sections were updated with revised **tables, thresholds, and classifications**, requiring designers to re-evaluate maximum allowable quantities and storage room design early in the project. ### 9\. How do the changes affect multifamily residential buildings? Sections **420.2** and **420.3** clarify that walls between sleeping units and dwelling units must be **fire partitions**, and horizontal separations must comply with **§711**. This strengthens fire/sound separation requirements in multi-family housing. ### 10\. Are these changes more about safety or flexibility? Both. - High-rise and correctional updates focus on **life safety**. - Atrium and care suite revisions introduce **significant design flexibility** while clarifying long-confusing rules. - Hazardous materials updates aim at **consistency and modern standards**. ## References Ask any code questions on California Building Code (CBC 2025) changes & get instant answers with cited sections [▶ Learn How it works (1 min)](/code) What can you ask? (Sample questions) - When does the 2025 CBC take effect and what editions does it adopt? - What are the key California amendments to the IBC in CBC 2025? - How do Title 24 energy requirements change in 2025? - What accessibility changes are in Chapter 11B of CBC 2025? [Explore Melt Code](/code) 1. ‍ [2022 California Building Code, Title 24, Part 2 (Volumes 1 & 2) with July 2024 Supplement updated](https://codes.iccsafe.org/content/CABC2022P4) 2. [2025 California Building Code Volumes 1 and 2, Title 24, Part 2](https://codes.iccsafe.org/content/CABC2025P1) ### Related Building Code Resources - [Building CodesWhat are the Key changes in Chapter 14 Exterior Walls of CBC 2025?](/blogs/key-changes-in-chapter-14-exterior-walls-of-cbc-2025) - [Building CodesWhat are the Key changes in Chapter 11B Accessibility to Public Buildings & Public Housing of CBC 2025?](/blogs/key-changes-in-chapter-11b-accessibility-to-public-buildings-public-housing-of-cbc-2025) - [Fire & Life SafetyWhat are the Key changes in Chapter 10 Means of Egress of CBC 2025?](/blogs/key-changes-in-chapter-10-means-of-egress-of-cbc-2025) - [Fire & Life SafetyWhat are the key Changes in Chapter 9 Fire Protection Systems California Building Code 2025?](/blogs/key-changes-in-chapter-9-fire-protection-systems-california-building-code-2025) - [Building CodesWhat are the key changes in Chapter 5 General Building Heights & Areas of CBC 2025?](/blogs/key-changes-in-chapter-5-general-building-heights-areas-of-cbc-2025) --- This blog is powered by Superblog. 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