CFC · California Fire Code

When is a smoke control system required under the CFC?

Summary: If the California Building Code or the California Fire Code says a building or building element needs smoke control (for example, all high‑rise buildings or pressurized elevator hoistways), the CFC’s §909 rules apply — you must design, equip, power, activate and test the system to meet the requirements in **§ 909.1**, **§ 909.21** and **§ 914.3.8**.

Ask a question free See coverage

Last reviewed: July 6, 2026

What the code requires — plain English

A smoke control system is required wherever the California Building Code or the California Fire Code specifically requires one; Section § 909.1 establishes this scope and purpose and ties CFC smoke-control requirements to other code triggers.

Two of the most common, explicit CFC triggers are: (1) all portions of high‑rise buildings — CFC § 914.3.8.1 requires a smoke control system in accordance with CBC §909 for high‑rise buildings, and (2) pressurized elevator hoistways/pressurization systems — elevator hoistway pressurization is addressed in CFC § 909.21 with specific equipment, activation and power requirements.

The single most important rule: if the CBC or CFC requires smoke control for a building type or condition, the system must be designed and tested to meet the CFC smoke‑control provisions (see § 909.1).

Requirements in detail

1) The fundamental trigger: scope and connection to the CBC

  • What § 909.1 says (scope): Section § 909.1 makes the CFC smoke control rules apply to mechanical or passive smoke control systems “where they are required for new buildings or portions thereof by provisions of the California Building Code or this code.” In short: the CFC contains the design/installation/testing rules, but the obligation to provide a system often comes from the CBC or other CFC sections.

2) High‑rise buildings

  • All portions of high‑rise buildings must be provided with a smoke control system in accordance with CBC §909 per CFC § 914.3.8.1. The CFC also cross‑references other high‑rise requirements (e.g., smokeproof exit enclosures).

3) Elevator hoistway pressurization (specific CFC requirements)

  • If an elevator hoistway is pressurized, it is treated as a smoke control system and must meet CFC § 909.21. That section requires items such as: fire‑resistance protection of the hoistway pressurization fan, a smoke detector to automatically shut down the fan if smoke is detected, separate systems per hoistway, specified fan capacity, standby power per §1203, activation by elevator‑lobby smoke detectors, and required testing and marking.

4) How the CFC expects the system to perform / design constraints

  • The CFC requires a rational engineering analysis to support the chosen smoke‑control method and that systems be designed per the §909 provisions (e.g., pressurization, airflow or exhaust methods) and accepted engineering practice. See § 909.1 and the design/analysis requirements in the Section 909 family of provisions.

Quick decision table (what to check on a project)

Trigger / situation Decision-relevant dimension/value (what to check) Code Reference
High‑rise building If building is a high‑rise, provide smoke control for all portions § 914.3.8.1
Elevator hoistway pressurization Pressurized hoistway treated as smoke control; supply fan capacity ≥ 1,000 cfm per door unless RDP specifies otherwise; standby power required; activation by elevator‑lobby smoke detectors § 909.21 (see §909.21.4.4, §909.21.5, §909.21.6)
Code-required smoke control (general) Does the CBC or another CFC section call for smoke control (CBC §909 referenced by CFC §909.1)? If yes, design per CFC §909 § 909.1
Where pressurized stairways/elevator hoistways are used These pressurization systems must comply with §909 (treated as smoke control) § 909.21 and § 909.6.3

Exceptions & special cases

  • The CFC links the requirement to the CBC: if the CBC does not require smoke control for a particular occupancy/condition, §909.1 does not by itself create a new obligation. Always confirm the CBC trigger first. § 909.1.
  • For high‑rise exit enclosures, § 914.3.8.2 requires compliance with CBC sections for smokeproof stair enclosures; there is a listed exception where exit enclosures serving three or fewer adjacent floors (where one is the level of exit discharge) are treated differently — see § 914.3.8.2.
  • Elevator hoistway pressurization is explicitly required to meet the §909.21 provisions; do not treat a simple HVAC fan as compliant without meeting the pressurization/fan/sensor/power/control requirements in § 909.21.

If you need an authoritative, complete list of every CBC trigger (specific CBC sections that call for smoke control in particular occupancies or conditions), that list is not fully reproduced here — check the CBC cross‑references that identify required smoke control and then apply § 909.1.

Common mistakes

  • Thinking any large fan = smoke control: the CFC explicitly treats mechanical smoke control systems as a distinct category and they are not equivalent to ordinary HVAC or exhaust systems; design must follow § 909 provisions.
  • Overlooking activation/power requirements for pressurization: elevator pressurization per § 909.21 requires smoke detection, standby power, and automatic activation on elevator lobby smoke detectors — missing any of these is a common plan review failure.
  • Confusing required scope: the obligation to provide a smoke control system flows from the CBC or other CFC sections (e.g., high‑rise requirement in § 914.3.8) — designers sometimes skip the step of identifying the initial CBC trigger.

Worked example — concrete scenario

Scenario: A 20‑story office building (highest occupied floor well above fire‑department access) will include elevators and enclosed elevator lobbies.

  1. Check applicability: CFC § 914.3.8.1 says all portions of high‑rise buildings must have a smoke control system in accordance with CBC §909, so the building requires smoke control.

  2. Elevator hoistways: The design includes pressurizing elevator hoistways to protect elevator lobbies. Because hoistway/stair pressurization is treated as smoke control, the elevator pressurization system must meet § 909.21.

  3. Apply numeric CFC requirements for the hoistway pressurization system:

    • Fan capacity: provide a supply fan capacity of not less than 1,000 cfm per door (or as specified by an RDP). If each elevator lobby has 2 doors, design fan ≥ 2,000 cfm per hoistway as a starting point. § 909.21.4.4.
    • Smoke detection: equip the fan system with a smoke detector that will automatically shut down the fan if smoke is detected within the system. § 909.21.4.2.
    • Standby power: provide standby power for the pressurization system in accordance with Section § 1203 (as required by § 909.21.5).
    • Activation: the pressurization must activate on elevator lobby smoke detectors (automatic activation). § 909.21.6.

  4. Commissioning and testing: Acceptance testing and special inspections per the §909 testing requirements apply — e.g., functional tests, pressure measurements and verification of sequences as described in § 909.18 and related subsections.

This example shows how the high‑level trigger (high‑rise) and the specific subsystem trigger (pressurized hoistway) combine to dictate both the need for a smoke control system and the technical requirements it must meet under the CFC.

Related provisions (quick list)

  • § 909.1 (Scope and purpose) — primary scope tying CFC requirements to CBC triggers.
  • § 909.21 (Elevator hoistway pressurization requirements: fan capacity, smoke detection, standby power, activation, testing).
  • § 914.3.8.1 / § 914.3.8.2 (High‑rise smoke control required; smokeproof exit enclosures and exception).
  • § 909.6.1 / § 909.6.3 (Pressure difference design and pressurized stairways/hoistways treated as smoke control).
  • § 909.17 (System response time — activation/sequence timing expectations).
  • § 909.18 (Acceptance testing, special inspection and commissioning requirements).

If you want, I can:

  • Map every CBC section that can trigger a smoke control requirement to the CFC design/testing requirements; or
  • Produce a checklist for plan reviewers keyed to the CFC clauses above (control panel, smoke detectors, fan capacities, standby power, testing records, firefighter's control panel actions, etc.).

Code references

Grounded in the retrieved California Fire Code — click a citation to read the verbatim passage:

  • CFC § 909.21.4.1 High relevance — show source text

    [BF] 909.21.4.1 Fire resistance. Where located within the building, the fan system that provides the pressurization shall be protected with the same fire-resistance rating required for the elevator shaft enclosure.

    [BF] 909.21.4.2 Smoke detection. The fan system shall be equipped with a smoke detector that will automatically shut down the fan system when smoke is detected within the system.

    [BF] 909.21.4.3 Separate systems. A separate fan system shall be used for each elevator hoistway.

    [BF] 909.21.4.4 Fan capacity. The supply fan shall be either adjustable with a capacity of not less than 1,000 cfm (0.4719 m [3] /s) per door, or that specified by a registered design professional to meet the requirements of a designed pressurization system.

    [BF] 909.21.5 Standby power. The pressurization system shall be provided with standby power in accordance with Section 1203.

    [BF] 909.21.6 Activation of pressurization system. The elevator pressurization system shall be activated upon activation of the elevator lobby smoke detectors.

    [BF] 909.21.7 Testing. Testing for performance shall be required in accordance with Section 909.18.8. System acceptance shall be in accordance with Section 909.19.

    [BF] 909.21.8 Marking and identification. Detection and control systems shall be marked in accordance with Section 909.14.

    [BF] 909.21.9 Control diagrams. Control diagrams shall be provided in accordance with Section 909.15.

    [BF] 909.21.10 Control panel. A control panel complying with Section 909.16 shall be provided.

    [BF] 909.21.11 System response time. Hoistway pressurization systems shall comply with the requirements for smoke control system response time in Section 909.17.

    909.22 Maintenance. Smoke control systems shall be maintained to ensure to a reasonable degree that the system is capable of controlling smoke for the duration required. The system shall be maintained in accordance with the manufacturer’s instructions and Sections 909.22.1 through 909.22.6.

    909.22.1 Schedule. A routine maintenance and operational testing program shall be initiated immediately after the smoke control system has passed the acceptance tests. A written schedule for routine maintenance and operational testing shall be established.

    909.22.2 Records. Records of smoke control system testing and maintenance shall be maintained. The record shall include the date of the maintenance, identification of the servicing personnel and notification of any unsatisfactory condition and the corrective action taken, including parts replaced.

    909.22.3 Testing. Operational testing of the smoke control system shall include all equipment such as initiating devices, fans, dampers, controls, doors and windows.

    909.22.4 Dedicated smoke control systems. Dedicated smoke control systems shall be operated for each control sequence semiannually. The system shall be tested under standby power conditions.

    909.22.5 Nondedicated smoke control systems. Nondedicated smoke control systems shall be operated for each control sequence annually. The system shall be tested under standby power conditions.

    2025 CALIFORNIA FIRE CODE 9-65

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

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

  • CFC § 405.4.3 High relevance — show source text

    405.4.3 Elevators. Where elevators are provided, each compartment shall have direct access to an elevator. Where an elevator serves more than one compartment, an enclosed elevator lobby shall be provided and shall be separated from each compartment by a smoke barrier in accordance with Section 709. Doorways in the smoke barrier shall be protected by fire door assemblies that comply with Section 716, shall comply with the smoke and draft control assembly requirements of Section 716.2.2.1 with the UL 1784 test conducted without an artificial bottom seal, and shall be automatic-closing by smoke detection in accordance with Section 716.2.6.6.

    405.5 Smoke control system. A smoke control system shall be provided in accordance with Sections 405.5.1 and 405.5.2.

    405.5.1 Control system. A smoke control system is required to control the migration of products of combustion in accordance with Section 909 and the provisions of this section. Smoke control shall restrict movement of smoke to the general area of fire origin and maintain means of egress in a usable condition.

    405.5.2 Compartment smoke control system. Where compartmentation is required, each compartment shall have an independent smoke control system. The system shall be automatically activated and capable of manual operation in accordance with Sections 907.2.18 and 907.2.19.

    [F] 405.6 Fire alarm systems. A fire alarm system shall be provided where required by Sections 907.2.18 and 907.2.19.

    [BE] 405.7 Means of egress. Means of egress shall be in accordance with Sections 405.7.1 and 405.7.2.

    [BE] 405.7.1 Number of exits. Each floor level shall be provided with not fewer than two exits. Where compartmentation is required by Section 405.4, each compartment shall have not fewer than one exit and not fewer than one exit access doorway into the adjoining compartment.

    [BE] 405.7.2 Smokeproof enclosure. Every required stairway serving floor levels more than 30 feet (9144 mm) below the finished floor of its level of exit discharge shall comply with the requirements for a smokeproof enclosure as provided in Section 1023.12.

    [F] 405.8 Standby and emergency power. A standby power system complying with Section 2702 shall be provided for the standby power loads specified in Section 405.8.1. An emergency power system complying with Section 2702 shall be provided for the emergency power loads specified in Section 405.8.2.

    [F] 405.8.1 Standby power loads. The following are classified as standby power loads:

    1. Smoke control system.
    2. Ventilation and automatic fire detection equipment for smokeproof enclosures.
    3. Elevators, as required in Section 3003.

    [F] 405.8.2 Emergency power loads. The following are classified as emergency power loads:

    1. Emergency voice/alarm communications systems.
    2. Fire alarm systems.
    3. Automatic fire detection systems.
    4. Elevator car lighting.

    4-14 2025 CALIFORNIA BUILDING CODE

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

    SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

    1. Means of egress and exit sign illumination as required by Chapter 10.

    2. Fire pumps.

  • CFC § 907.8.4 High relevance — show source text

    907.8.4 Inspection, testing and maintenance. The building owner shall be responsible to maintain the fire and life safety systems in an operable condition at all times. Service personnel shall meet the qualification requirements of NFPA 72 for inspection, testing and maintenance of such systems. Records of inspection, testing and maintenance shall be maintained.

    907.9 Where required in existing buildings and structures. An approved fire alarm system shall be provided in existing buildings and structures where required in Chapter 11.

    907.10 Smoke alarm maintenance. Smoke alarms shall be tested and maintained in accordance with the manufacturer’s instruc tions and this code.

    907.10.1 Smoke alarm replacement. Smoke alarms shall be replaced when any of the following apply:

    1. The smoke alarm fails to respond to operability tests.

    2. The smoke alarm exceeds 10 years from the date of manufacture marked on the unit, unless an earlier replacement is specified in the manufacturer’s instructions.

    3. The smoke alarm end-of-life signal is sounded.

    4. The smoke alarm date of manufacture cannot be determined.

    Where the replacement of smoke alarms is required by this section, smoke alarms shall not be required to include the 520-Hz signal unless the smoke alarms to be replaced include that signal.

    SECTION 908—EMERGENCY ALARM SYSTEMS

    908.1 Group H occupancies. Emergency alarms for the detection and notification of an emergency condition in Group H occupancies shall be provided as required in Chapter 50. 908.2 Group H-5 occupancy. Emergency alarms for notification of an emergency condition in an HPM facility shall be provided as required in Section 2703.12. 908.3 Fire alarm system interface. Where an emergency alarm system is interfaced with a building’s fire alarm system, the signal produced at the fire alarm control unit shall be a supervisory signal. 908.4 Carbon dioxide enrichment systems. A gas detection system shall be provided in rooms and indoor areas in which carbon diox- ide enrichment processes are located in accordance with Section 5307.3.2.

    SECTION 909—SMOKE CONTROL SYSTEMS

    909.1 Scope and purpose. This section applies to mechanical or passive smoke control systems where they are required for new buildings or portions thereof by provisions of the California Building Code or this code. The purpose of this section is to establish minimum requirements for the design, installation and acceptance testing of smoke control systems that are intended to provide a tenable environment for the evacuation or relocation of occupants. These provisions are not intended for the preservation of contents, the timely restoration of operations or for assistance in fire suppression or overhaul activities. Smoke control systems regulated by this section serve a different purpose than the smoke- and heat-removal provisions found in Section 910. Mechanical smoke control systems shall not be considered exhaust systems under Chapter 5 of the California Mechanical Code .

    909.2 General design requirements. Buildings, structures, or parts thereof required by the California Building Code or this code to have a smoke control system or systems shall have such systems designed in accordance with the applicable requirements of Section 909 and the generally accepted and well-established principles of engineering relevant to the design. The construction documents shall include sufficient information and detail to describe adequately the elements of the design necessary for the proper implementation of the smoke control systems. These documents shall be accompanied with sufficient information and analysis to demonstrate compliance with these provisions.

    2025 CALIFORNIA FIRE CODE 9-57

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

  • CFC § 914.3.4 Medium relevance — show source text

    914.3.4 Automatic smoke detection. Smoke detection shall be provided in accordance with Section 907.2.13.1.

    914.3.5 Emergency voice/alarm communication system. An emergency voice/alarm communication system shall be provided in accordance with Section 907.5.2.2.

    914.3.6 Emergency responder communication coverage. In-building, two-way emergency responder communication coverage shall be provided in accordance with Section 510.

    914.3.7 Fire command. A fire command center complying with Section 508 shall be provided in a location approved by the fire department.

    914.3.8 Smoke control.

    914.3.8.1 Smoke control system. All portions of high-rise buildings shall be provided with a smoke control system in accordance with California Building Code, Section 909.

    914.3.8.2 Smokeproof exit enclosures. Every exit enclosure in high-rise buildings shall comply with California Building Code, Sections 909.20 and 1023.12. Every required stairway in Group I-2 occupancies serving floors more than 75 feet (22 860 mm) above the lowest level of fire department vehicle access shall comply with Sections 909.20 and 1023.12 of the California Building Code.

    Exception: In high-rise buildings, exit enclosures serving three or less adjacent floors where one of the adjacent floors is the level of exit discharge.

    914.4 Atriums. Atriums shall comply with Sections 914.4.1 and 914.4.2.

    914.4.1 Automatic sprinkler system. An approved automatic sprinkler system shall be installed throughout the entire building.

    Exceptions:

    1. That area of a building adjacent to or above the atrium need not be sprinklered, provided that portion of the building is separated from the atrium portion by not less than a 2-hour fire barrier constructed in accordance with Section 707 of the California Building Code or horizontal assemblies constructed in accordance with Section 711 of the California Building Code, or both.
    2. Where the ceiling of the atrium is more than 55 feet (16 764 mm) above the floor, sprinkler protection at the ceiling of the atrium is not required.

    914.4.2 Fire alarm system. A fire alarm system shall be provided where required by Section 907.2.14.

    914.5 Underground buildings. Underground buildings shall comply with Sections 914.5.1 through 914.5.5.

    914.5.1 Automatic sprinkler system. The highest level of exit discharge serving the underground portions of the building and all levels below shall be equipped with an automatic sprinkler system installed in accordance with Section 903.3.1.1. Waterflow switches and control valves shall be supervised in accordance with Section 903.4.1.

    914.5.2 Smoke control system. A smoke control system is required to control the migration of products of combustion in accordance with Section 909 and provisions of this section. Smoke control shall restrict movement of smoke to the general area of fire origin and maintain means of egress in a usable condition.

    914.5.3 Compartment smoke control system. Where compartmentation is required by Section 405.4 of the California Building Code, each compartment shall have an independent smoke control system. The system shall be automatically activated and capable of manual operation in accordance with Section 907.2.18.

  • CFC § 909.16.3 Medium relevance — show source text

    909.16.3 Control action and priorities. The firefighter’s control panel actions shall be as follows:

    1. ON-OFF and OPEN-CLOSE control actions shall have the highest priority of any control point within the building. Once issued from the firefighter’s control panel, automatic or manual control from any other control point within the building shall not contradict the control action. Where automatic means are provided to interrupt normal, nonemergency equipment operation or produce a specific result to safeguard the building or equipment including, but not limited to, duct freezestats, duct smoke detectors, high-temperature cutouts, temperature-actuated linkage and similar devices, such means shall be capable of being overridden by the firefighter’s control panel. The last control action as indicated by each firefighter’s control panel switch position shall prevail. Control actions shall not require the smoke control system to assume more than one configuration at any one time.

    Exception: Power disconnects required by the California Electrical Code . 2. Only the AUTO position of each three-position firefighter’s control panel switch shall allow automatic or manual control action from other control points within the building. The AUTO position shall be the NORMAL, nonemergency, building control position. Where a firefighter’s control panel is in the AUTO position, the actual status of the device (on, off, open, closed) shall continue to be indicated by the status indicator described in Section 909.16.1. Where directed by an automatic signal to assume an emergency condition, the NORMAL position shall become the emergency condition for that device or group of devices within the zone. Control actions shall not require the smoke control system to assume more than one configuration at any one time.

    909.17 System response time. Smoke-control system activation shall be initiated immediately after receipt of an appropriate automatic or manual activation command. Smoke control systems shall activate individual components (such as dampers and fans) in the sequence necessary to prevent physical damage to the fans, dampers, ducts and other equipment. For purposes of smoke control, the firefighter’s control panel response time shall be the same for automatic or manual smoke control action initiated from any other building control point. The total response time, including that necessary for detection, shutdown of operating equipment and smoke control system startup, shall allow for full operational mode to be achieved before the conditions in the space exceed the design smoke condition. Upon receipt of an alarm condition at the fire alarm control panel, fans, dampers and automatic doors shall have achieved their proper operating state and the final status shall be indicated at the smoke control panel within 90 seconds. The system response time for each component and their sequential relationships shall be detailed in the required rational analysis and verification of their installed condition reported in the required final report.

    909.18 Acceptance testing. Devices, equipment, components and sequences shall be individually tested. These tests, in addition to those required by other provisions of this code, shall consist of determination of function, sequence and, where applicable, capacity of their installed condition.

    909.18.1 Detection devices. Smoke or fire detectors that are a part of a smoke control system shall be tested in accordance with Chapter 9 in their installed condition. Where applicable, this testing shall include verification of airflow in both minimum and maximum conditions.

    909.18.2 Ducts. Ducts that are part of a smoke control system shall be traversed using generally accepted practices to determine actual air quantities.

    909.18.3 Dampers. Dampers shall be tested for function in their installed condition in accordance with NFPA 80 and NFPA 105.

  • CFC § 9-44 Medium relevance — show source text

    9-44 2025 CALIFORNIA BUILDING CODE

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

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    In buildings permitted to be not equipped throughout with automatic sprinkler systems, the smoke control system shall be designed to achieve pressure differences not less than two times the maximum calculated pressure difference produced by the design fire.

    [F] 909.6.2 Maximum pressure difference. The maximum air pressure difference across a smoke barrier shall be determined by required door-opening or closing forces. The actual force required to open exit doors when the system is in the smoke control mode shall be in accordance with Section 1010.1.3. Opening and closing forces for other doors shall be determined by standard engineering methods for the resolution of forces and reactions. The calculated force to set a side-hinged, swinging door in motion shall be determined by:

    Equation 9-1 F = F dc + K ( WA Δ P )/2( W - d )

    where:

    A = Door area, square feet (m [2] ).

    d = Distance from door handle to latch edge of door, feet (m).

    F = Total door opening force, pounds (N).

    F dc = Force required to overcome closing device, pounds (N).

    K = Coefficient 5.2 (1.0).

    W = Door width, feet (m).

    Δ P = Design pressure difference, inches of water (Pa).

    [F] 909.6.3 Pressurized stairways and elevator hoistways. Where stairways or elevator hoistways are pressurized, such pressurization systems shall comply with Section 909 as smoke control systems, in addition to the requirements of Sections 909.20 of this code and 909.21 of the California Fire Code .

    [F] 909.7 Airflow design method. Where approved by the fire code official, smoke migration through openings fixed in a permanently open position, which are located between smoke control zones by the use of the airflow method, shall be permitted. The design airflow shall be in accordance with this section. Airflow shall be directed to limit smoke migration from the fire zone. The geometry of openings shall be considered to prevent flow reversal from turbulent effects. Smoke control systems using the airflow method shall be designed in accordance with NFPA 92.

    [F] 909.7.1 Prohibited conditions. This method shall not be employed where either the quantity of air or the velocity of the airflow will adversely affect other portions of the smoke control system, unduly intensify the fire, disrupt plume dynamics or interfere with exiting. Airflow toward the fire shall not exceed 200 feet per minute (1.02 m/s). Where the calculated airflow exceeds this limit, the airflow method shall not be used.

    [F] 909.8 Exhaust method. Where approved by the fire code official, mechanical smoke control for large enclosed volumes, such as in atriums or malls, shall be permitted to utilize the exhaust method. Smoke control systems using the exhaust method shall be designed in accordance with NFPA 92.

    [F] 909.8.1 Smoke layer. The height of the lowest horizontal surface of the smoke layer interface shall be maintained not less than 6 feet (1829 mm) above a walking surface that forms a portion of a required egress system within the smoke zone.

  • CFC § 9-58 Medium relevance — show source text

    9-58 2025 CALIFORNIA FIRE CODE

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

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    the California Building Code . The doors shall be close-fitting within operational tolerances and shall not have a center mullion. Positive-latching devices are required. Doors installed across corridors shall comply with Section 1010.1.1. 4. In Group I-2, R-2.1 and ambulatory care facilities, where such doors are special-purpose horizontal sliding, accordion or folding door assemblies installed in accordance with Section 1010.3.3 and are automatic closing by smoke detection in accordance with Section 716.2.6.6 of the California Building Code they shall be protected in accordance with Section 716 of the California Building Code. Doors installed across corridors shall comply with Section 1010.1.1.

    1. Group I-3.
    2. Openings between smoke zones with clear ceiling heights of 14 feet (4267 mm) or greater and bank-down capacity of greater than 20 minutes as determined by the design fire size. 7. In Group I-2, smoke damper activation may be accomplished by a fire alarm control unit provided that an open area smoke detection system is provided within all areas served by an HVAC system.

    909.5.3.1 Group I-2, R-2.1 and ambulatory care facilities. In Group I-2, R-2.1 and ambulatory care facilities, where doors are installed across a corridor, the doors shall be automatic closing by smoke detection in accordance with Section 716.2.6.6 of the California Building Code and shall have a vision panel with fire-protection-rated glazing materials in fire-protection-rated frames, the area of which shall not exceed that tested. In Group I-2, where swinging doors are installed across a corridor, such doors shall be opposite swinging pairs.

    909.5.3.2 Ducts and air transfer openings. Ducts and air transfer openings are required to be protected with a minimum Class II, 250°F (121°C) smoke damper complying with Section 717 of the California Building Code .

    909.6 Pressurization method. The primary mechanical means of controlling smoke shall be by pressure differences across smoke barriers. Maintenance of a tenable environment is not required in the smoke-control zone of fire origin.

    909.6.1 Minimum pressure difference. The pressure difference across a smoke barrier used to separate smoke zones shall be not less than 0.05-inch water gage (0.0124 kPa) in buildings equipped throughout with automatic sprinkler systems.

    In buildings permitted to be not equipped throughout with automatic sprinkler systems, the smoke control system shall be designed to achieve pressure differences not less than two times the maximum calculated pressure difference produced by the design fire.

    909.6.2 Maximum pressure difference. The maximum air pressure difference across a smoke barrier shall be determined by required door-opening or closing forces. The actual force required to open exit doors when the system is in the smoke control mode shall be in accordance with Section 1010.1.3. Opening and closing forces for other doors shall be determined by standard engineering methods for the resolution of forces and reactions. The calculated force to set a side-hinged, swinging door in motion shall be determined by:

  • CFC § 0.019 Medium relevance — show source text

    Exceptions:

    1. Smoke dampers are not required where the building is equipped throughout with an approved smoke control system in accordance with Section 909, and smoke dampers are not necessary for the operation and control of the system.
    2. Smoke dampers are not required in corridor penetrations where the duct is constructed of steel not less than 0.019 inch (0.48 mm) in thickness and there are no openings serving the corridor.

    [SFM] For Group A, E, H, I, L and R occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, a listed smoke damper designed to resist the passage of smoke shall also be provided at each point a duct or air transfer opening penetrates a fire-resistance rated corridor enclosure required to have smoke and draft doors in accordance with Section 716.2.2.1 or doors that provide an effective barrier to limit the transfer of smoke in accordance with Section 407.3.1.

    Exceptions: 1. Smoke dampers are not required where ducts are used as part of an approved mechanical smoke control system designed in accordance with Section 909 and where the smoke damper will interfere with the operation of the smoke control system. 2. Smoke dampers are not required in corridor penetrations where the duct is constructed of steel not less than 0.019 inch (0.48 mm) in thickness and there are no openings serving the corridor. 717.5.5 Smoke barriers. A listed smoke damper designed to resist the passage of smoke shall be provided at each point a duct or air transfer opening penetrates a smoke barrier. Smoke dampers and smoke damper actuation methods shall comply with Section 717.3.3.2.

    Exception: Smoke dampers are not required where the openings in ducts are limited to a single smoke compartment and the ducts are constructed of steel. � 717.5.6 Exterior walls. Ducts and air transfer openings in fire-resistance-rated exterior walls required to have protected openings in accordance with Section 705.11 shall be protected with listed fire dampers installed in accordance with their listing.

    7-38 2025 CALIFORNIA BUILDING CODE

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

    FIRE AND SMOKE PROTECTION FEATURES

    717.5.7 Smoke partitions. A listed smoke damper designed to resist the passage of smoke shall be provided at each point that an air transfer opening penetrates a smoke partition. Smoke dampers and smoke damper actuation methods shall comply with Section 717.3.3.2.

    Exception: Where the installation of a smoke damper will interfere with the operation of a required smoke control system in accordance with Section 909, approved alternative protection shall be utilized.

    717.6 Horizontal assemblies. Penetrations by ducts and air transfer openings of a floor, floor/ceiling assembly or the ceiling membrane of a roof/ceiling assembly shall be protected by a shaft enclosure that complies with Section 713 or shall comply with Sections 717.6.1 through 717.6.3.

  • CFC § 907.8 Medium relevance — show source text

    [F] 907.8 Inspection, testing and maintenance. The maintenance and testing schedules and procedures for fire alarm and fire detection systems shall be in accordance with Section 907.8 of the California Fire Code .

    SECTION 908—EMERGENCY ALARM SYSTEMS

    [F] 908.1 Group H occupancies. Emergency alarms for the detection and notification of an emergency condition in Group H occupancies shall be provided in accordance with Section 415.5.

    [F] 908.2 Group H-5 occupancy. Emergency alarms for notification of an emergency condition in an HPM facility shall be provided as required in Section 415.11.4.

    [F] 908.3 Fire alarm system interface. Where an emergency alarm system is interfaced with a building’s fire alarm system, the signal produced at the fire alarm control unit shall be a supervisory signal.

    SECTION 909—SMOKE CONTROL SYSTEMS

    [F] 909.1 Scope and purpose. This section applies to mechanical or passive smoke control systems where they are required by other provisions of this code. The purpose of this section is to establish minimum requirements for the design, installation and acceptance testing of smoke control systems that are intended to provide a tenable environment for the evacuation or relocation of occupants. These provisions are not intended for the preservation of contents, the timely restoration of operations or for assistance in fire suppression or overhaul activities. Smoke control systems regulated by this section serve a different purpose than the smoke- and heat-removal provisions found in Section 910. Mechanical smoke control systems shall not be considered exhaust systems under Chapter 5 of the California Mechanical Code .

    [F] 909.2 General design requirements. Buildings, structures or parts thereof required by this code to have a smoke control system or systems shall have such systems designed in accordance with the applicable requirements of Section 909 and the generally accepted and well-established principles of engineering relevant to the design. The construction documents shall include sufficient information and detail to adequately describe the elements of the design necessary for the proper implementation of the smoke control systems. These documents shall be accompanied by sufficient information and analysis to demonstrate compliance with these provisions.

    [F] 909.3 Special inspection and test requirements. In addition to the ordinary inspection and test requirements that buildings, structures and parts thereof are required to undergo, smoke control systems subject to the provisions of Section 909 shall undergo special inspections and tests sufficient to verify the proper commissioning of the smoke control design in its final installed condition. The design submission accompanying the construction documents shall clearly detail procedures and methods to be used and the items subject to such inspections and tests. Such commissioning shall be in accordance with generally accepted engineering practice and, where possible, based on published standards for the particular testing involved. The special inspections and tests required by this section shall be conducted under the same terms in Section 1704.

    [F] 909.4 Analysis. A rational analysis supporting the types of smoke control systems to be employed, their methods of operation, the systems supporting them and the methods of construction to be utilized shall accompany the submitted construction documents and shall include, but not be limited to, the items indicated in Sections 909.4.1 through 909.4.7.

    [F] 909.4.1 Stack effect. The system shall be designed such that the maximum probable normal or reverse stack effect will not adversely interfere with the system’s capabilities. In determining the maximum probable stack effect, altitude, elevation, weather history and interior temperatures shall be used.

  • CFC § 717.3.2.4 Medium relevance — show source text

    717.3.2.4 Corridor damper ratings. Corridor dampers shall have the following minimum ratings:

    1. One-hour fire-resistance rating.
    2. Class I or II leakage rating as specified in Section 717.3.2.2.

    717.3.3 Damper actuation. Damper actuation shall be in accordance with Sections 717.3.3.1 through 717.3.3.5 as applicable.

    717.3.3.1 Fire damper actuation. Primary heat responsive devices used to actuate fire dampers shall meet one of the following requirements:

    1. The operating temperature shall be approximately 50°F (10°C) above the normal temperature within the duct system, but not less than 160°F (71°C).
    2. The operating temperature shall be not more than 350°F (177°C) where located in a smoke control system complying with Section 909.

    717.3.3.2 Smoke damper actuation. The smoke damper shall close upon actuation of a listed smoke detector or detectors installed in accordance with Section 907.3 and one of the following methods, as applicable:

    1. Where a smoke damper is installed within a duct, a smoke detector shall be installed inside the duct or outside the duct with sampling tubes protruding into the duct. The detector or tubes within the duct shall be within 5 feet (1524 mm) of the damper. Air outlets and inlets shall not be located between the detector or tubes and the damper. The detector shall be listed for the air velocity, temperature and humidity anticipated at the point where it is installed. Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate.
    2. Where a smoke damper is installed above smoke barrier doors in a smoke barrier, a spot-type detector shall be installed on either side of the smoke barrier door opening. The detector shall be listed for releasing service if used for direct interface with the damper.
    3. Where a smoke damper is installed within an air transfer opening in a wall, a spot-type detector shall be installed within 5 feet (1524 mm) horizontally of the damper. The detector shall be listed for releasing service if used for direct interface with the damper.

    2025 CALIFORNIA BUILDING CODE 7-35

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

    FIRE AND SMOKE PROTECTION FEATURES

    1. Where a smoke damper is installed in a corridor wall or ceiling, the damper shall be permitted to be controlled by a smoke detection system installed in the corridor.
    2. Where a smoke detection system is installed in all areas served by the duct in which the damper will be located, the smoke dampers shall be permitted to be controlled by the smoke detection system.

    717.3.3.3 Combination fire/smoke damper actuation. Combination fire/smoke damper actuation shall be in accordance with Sections 717.3.3.1 and 717.3.3.2. Combination fire/smoke dampers installed in smoke control system shaft penetrations shall not be activated by local area smoke detection unless it is secondary to the smoke control system controls.

    717.3.3.4 Ceiling radiation damper actuation. The operating temperature of a ceiling radiation damper actuation device shall be 50°F (27.8°C) above the normal temperature within the duct system, but not less than 160°F (71°C).

  • CFC § 2.1. Medium relevance — show source text

    Exception: In patient and client rooms equipped with existing automatic door closers having integral smoke detec- tor, the integral detector is allowed to substitute for the room smoke detector, provided it meets all the required alerting functions. 2. Group I-2 nurse stations. A minimum of one (1) smoke detector shall be installed at the nurse station and centrally located.

    3. In waiting areas and corridors onto which they open, in the same smoke compartment, in accordance with Section 407.2.1.

    1. In areas where patients are restrained, smoke detectors shall be installed at ceilings throughout all occupied areas and mechanical/electrical spaces of smoke compartments and in adjacent smoke compartments where occupants of those compartments utilize the same means of egress.

    [F] 907.2.6.3 Group I-3 occupancies. Group I-3 occupancies shall be equipped with a manual fire alarm system and automatic smoke detection system installed for alerting staff.

    Exception: An automatic smoke detection system is not required within temporary holding cells.

    9-28 2025 CALIFORNIA BUILDING CODE

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

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    [F] 907.2.6.3.1 System initiation. Actuation of an automatic fire-extinguishing system, automatic sprinkler system, a manual fire alarm box or a fire detector shall initiate an approved fire alarm signal that automatically notifies staff.

    [F] 907.2.6.3.2 Manual fire alarm boxes. Manual fire alarm boxes are not required to be located in accordance with Section 907.4.2 where the fire alarm boxes are provided at staff-attended locations having direct supervision over areas where manual fire alarm boxes have been omitted.

    [F] 907.2.6.3.2.1 Manual fire alarm boxes in detainee areas. Manual fire alarm boxes are allowed to be locked in areas occupied by detainees, provided that staff members are present within the subject area and have keys readily available to operate the manual fire alarm boxes.

    [F] 907.2.6.3.3 Automatic smoke detection system. An automatic smoke detection system shall be installed throughout resident housing areas, including sleeping units and contiguous day rooms, group activity spaces and other common spaces normally open to residents.

    Exceptions:

    1. Other approved smoke detection arrangements may be used to prevent damage or tampering or for other purposes provided the function of detecting any fire is fulfilled and the location of the detectors is such that the speed of detection will be equivalent to that provided by the spacing and location required in accordance with NFPA 72 as referenced in Chapter 35. This may include the location of detectors in return air ducts from cells, behind grilles or in other locations. Spot type, combination duct and open area smoke detectors may be used when located not more than 14 inches (356 mm) from the return air grill. For initiation and annunciation purposes, these detectors may be combined in groups of four. The fire code official having jurisdiction, however, must approve the proposed equivalent performance of the design. 2. For detention housing and/or mental health housing area(s), including correctional medical and mental health uses, automatic smoke detection system in sleeping units shall not be required when all of the following conditions are met:
  • CFC § 909.1 Medium relevance — show source text

    SECTION 909—SMOKE CONTROL SYSTEMS

    909.1 Scope and purpose. This section applies to mechanical or passive smoke control systems where they are required for new buildings or portions thereof by provisions of the California Building Code or this code. The purpose of this section is to establish minimum requirements for the design, installation and acceptance testing of smoke control systems that are intended to provide a tenable environment for the evacuation or relocation of occupants. These provisions are not intended for the preservation of contents, the timely restoration of operations or for assistance in fire suppression or overhaul activities. Smoke control systems regulated by this section serve a different purpose than the smoke- and heat-removal provisions found in Section 910. Mechanical smoke control systems shall not be considered exhaust systems under Chapter 5 of the California Mechanical Code .

    909.2 General design requirements. Buildings, structures, or parts thereof required by the California Building Code or this code to have a smoke control system or systems shall have such systems designed in accordance with the applicable requirements of Section 909 and the generally accepted and well-established principles of engineering relevant to the design. The construction documents shall include sufficient information and detail to describe adequately the elements of the design necessary for the proper implementation of the smoke control systems. These documents shall be accompanied with sufficient information and analysis to demonstrate compliance with these provisions.

    2025 CALIFORNIA FIRE CODE 9-57

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

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

    909.3 Special inspection and test requirements. In addition to the ordinary inspection and test requirements that buildings, structures and parts thereof are required to undergo, smoke control systems subject to the provisions of Section 909 shall undergo special inspections and tests sufficient to verify the proper commissioning of the smoke control design in its final installed condition. The design submission accompanying the construction documents shall clearly detail procedures and methods to be used and the items subject to such inspections and tests. Such commissioning shall be in accordance with generally accepted engineering practice and, where possible, based on published standards for the particular testing involved. The special inspections and tests required by this section shall be conducted under the same terms as in Section 1704 of the California Building Code .

    909.4 Analysis. A rational analysis supporting the types of smoke control systems to be employed, the methods of their operations, the systems supporting them and the methods of construction to be utilized shall accompany the construction documents submission and include, but not be limited to, the items indicated in Sections 909.4.1 through 909.4.7.

    909.4.1 Stack effect. The system shall be designed such that the maximum probable normal or reverse stack effect will not adversely interfere with the system’s capabilities. In determining the maximum probable stack effect, altitude, elevation, weather history and interior temperatures shall be used.

    909.4.2 Temperature effect of fire. Buoyancy and expansion caused by the design fire in accordance with Section 909.9 shall be analyzed. The system shall be designed such that these effects do not adversely interfere with the system’s capabilities.

    909.4.3 Wind effect. The design shall consider the adverse effects of wind. Such consideration shall be consistent with the windloading provisions of the California Building Code .

Frequently asked questions

When does § 909.1 by itself require a smoke control system?

It does not by itself create a new obligation — § 909.1 sets the design/installation/testing rules for smoke control systems “where they are required” by the CBC or CFC. Always identify the initial CBC/CFC trigger first.

Is an ordinary HVAC fan ever acceptable as a smoke control fan?

Not unless it is designed and documented as part of a smoke control system meeting the CFC §909 requirements (controls, detectors, capacity, sequences, power, testing). §909.1 clarifies that mechanical smoke control is a distinct type of system.

Are all high‑rise buildings required to have smoke control?

Yes — CFC § 914.3.8.1 requires that all portions of high‑rise buildings be provided with a smoke control system in accordance with CBC §909. Confirm applicable CBC definitions for high‑rise in the CBC text.

For an elevator pressurization system, how is fan size figured in the CFC?

CFC § 909.21.4.4 specifies a supply fan capacity of not less than 1,000 cfm per door, or as specified by a registered design professional. Other controls, detection and standby power requirements are in §909.21.

What testing is required after installation?

Smoke control systems must undergo acceptance testing and special inspections per CFC § 909.18 (including pressure, airflow and sequence verification) and be tested by qualified agencies as required.

More in California Fire Code

Ask about the CFC

Get cited, plain-English answers on the California Fire Code for your project — any code section, any scenario.

Start Free Trial

Related in the CFC

What are the design, acceptance testing and maintenance requirements for smoke control systems?

When are smoke and heat vents or mechanical smoke removal required and how are they installed?

Special smoke-control rules for high-rise and underground buildings

Smoke Control and Smoke Removal

California Fire Code