CFC · California Fire Code
How to use Appendix B (and Appendix BB for schools) to determine fire‑flow
To set required fire flow, measure the building’s total floor area per the code, identify the construction type, then use Appendix B (or Appendix BB for schools) tables to read the required gallons‑per‑minute and duration; automatic sprinklers may reduce the table value but minimums apply and the water supply must meet the sprinkler demand or the table value—whichever is greater.
Last reviewed: July 6, 2026
What the code requires — plain English
- The building’s required fire flow must be determined by an approved method or Appendix B; for schools, Appendix BB applies as adopted by the State Fire Marshal. § 507.3 requires using an approved method or Appendix B to set fire‑flow requirements.
- Appendix B (and Appendix BB for school buildings) give a consistent, table‑based procedure keyed to construction type and fire area; jurisdictions may adopt and use these tables or another approved method. § B101.1 and the appendix introductory notes explain this intent.
Determine the building’s fire area (total floor area per the code), find the construction type, then read the matching required fire flow and flow duration from Appendix B (or Appendix BB for schools). Sprinkler systems may reduce required flow per the appendix rules, but minimums apply.
Requirements in detail
Key defined terms (first mention bolded)
- FIRE FLOW — the flow rate available for firefighting, measured at 20 psi residual pressure. § B102.1 / § BB102.1.
- FIRE‑FLOW CALCULATION AREA / FIRE AREA — the total floor area of all floor levels within the exterior walls and under roof projections (with special rules for certain construction types). § B104.1 / § BB104.1.
Step‑by‑step decision dimensions
Use this short decision table to identify what you must determine and where the code points you.
| Decision input | What to do / value to find | Code reference |
|---|---|---|
| Which procedure governs (jurisdiction adoption)? | Use an approved method OR Appendix B; for school buildings use Appendix BB where applicable. | § 507.3; § B101.1; § BB101.1. |
| How to measure area | Total floor area within exterior walls (all levels). For Type I/IB see special rule: use area of the three largest successive floors. | § B104.1; Exception; § BB104.1 / § BB104.3. |
| Which table to read | For most buildings Appendix B tables (B105 series); for school buildings use Table BB105.1. | § B105.1; § BB105.1. |
| Automatic sprinklers present? | If yes, apply the allowed reductions in the appendix (e.g., Appendix B reductions per § B105.2; Appendix BB allows up to 75% reduction for schools but not less than 1500 gpm). | § B105.2; § BB105.1 (Exception). |
| Fire department modifications | Fire code official may reduce (rural/isolated) or increase (conflagration risk) the required fire flow — increase not more than 2×. | § B103.1 / § B103.2. |
| Water supply for sprinklered buildings | Water supply must provide the greater of sprinkler system demand (including hose stream allowance) or the required fire flow from the table. | § B105.3. |
What the Appendix tables give (how to read them)
- Appendix tables tie construction type (per the California Building Code) to fire‑area ranges and list the minimum fire flow (gpm) and flow duration (hours) for each range. See the preface in Appendix B describing the table methodology. § B101.1 and the Appendix introductory notes.
- Appendix BB replicates this approach for school buildings and provides Table BB105.1 of minimum flows and durations by construction type and area; examples of area ranges and the corresponding flows appear in Table BB105.1. § BB105.1 and Table BB105.1.
Note: The full numeric tables in Appendix B (non‑residential Table B105.1(2), etc.) are the primary source of required gpm values. If you need a specific non‑residential numeric lookup from Table B105.1(2) and it’s not shown here, refer to the adopted CFC appendix table in your jurisdiction’s code book because the code text (table content) must be read directly.
Exceptions & special cases
- Appendix material is not automatically mandatory statewide; it is a tool jurisdictions can adopt. Do not assume Appendix B is binding unless the local adopting ordinance references it. See the appendix preface and § B101.1.
- The fire code official may reduce requirements for isolated/rural buildings (practicality) or increase requirements where there is unusual conflagration risk — see § B103.1 and § B103.2.
- Where no water system exists, the fire code official may rely on NFPA 1142 or the California Wildland‑Urban Interface Code for water supply criteria. § B103.3.
- For schools specifically, Appendix BB permits an up to 75% reduction in required fire flow when an approved automatic sprinkler system is provided; however the reduced fire flow shall not be less than 1500 gpm. § BB105.1 (Exception).
- For buildings with automatic sprinklers, Appendix B requires the water supply to meet the greater of the sprinkler demand or the required table fire flow. § B105.3.
Common mistakes
- Measuring the wrong area: forgetting to include all floor levels within the exterior walls, or failing to apply the three largest successive floors rule for Type I/IB where applicable. See § B104.1 and § BB104.3.
- Assuming Appendix B is mandatory everywhere — it’s a jurisdictional tool unless adopted. See § B101.1 and the appendix prefatory note.
- Incorrect sprinkler reductions: applying a percent reduction without checking the appendix minima (e.g., Appendix BB’s 1500 gpm minimum) or the required reduction floor in Appendix B (25% rules and minimums). See § B105.2 and § BB105.1 (Exception).
- Ignoring the fire code official’s authority to modify requirements on a site‑specific basis (see § B103.1 / § B103.2).
Worked example — school building
Scenario: A new school building under review, constructed Type IB, with three floors measuring 7,000 ft², 6,500 ft² and 6,000 ft² (total = 19,500 ft²). The building will be sprinklered.
- Compute the fire area: Appendix BB defines fire area as the total floor area of all levels within exterior walls; for Type IB the fire area is the area of the three largest successive floors — here all three floors, total 19,500 ft². § BB104.1 / § BB104.3.
- Find the table entry: Table BB105.1 lists minimum fire flow and flow duration by construction type and area ranges; for Type IA/IB the table row covering 0–22,700 ft² shows 1,500 gpm for 2 hours (see Table BB105.1). § BB105.1 and Table BB105.1.
- Apply sprinkler reduction: Appendix BB allows up to 75% reduction when an approved automatic sprinkler system is provided, but the reduced fire flow shall not be less than 1500 gpm. In this case the base table value is 1500 gpm, so even with sprinklers the required flow cannot be reduced below 1500 gpm; required remains 1,500 gpm for 2 hours. § BB105.1 (Exception).
- Confirm water supply: Per Appendix B guidance, the water supply for a sprinklered building must provide the greater of the sprinkler demand (including hose stream) or the required fire flow — ensure the system design meets the larger of the two. § B105.3.
Bottom line for this example: required fire flow = 1,500 gpm for 2 hours, and the water supply design must accommodate either the sprinkler demand (if greater) or this table value. § BB105.1; § B105.3.
Related provisions (CFC sections)
- § 507.3 — Fire flow: "shall be determined by an approved method or Appendix B."
- § B101.1 — Appendix B scope and use as a procedural tool.
- § B102.1 — Definitions (FIRE FLOW, FIRE‑FLOW CALCULATION AREA).
- § B103.1 / § B103.2 / § B103.3 — Authority for reductions/increases and guidance for areas without water supply.
- § B104.1 / § B104.2 — How to calculate fire‑flow calculation area and area separation rules.
- § B105.2 / § B105.3 — Sprinkler reductions and water supply for sprinklered buildings.
- § BB101.1 / § BB104.1 / § BB104.3 / § BB105.1 — Appendix BB scope, fire area rules for schools, and Table BB105.1 including sprinkler reduction exception.
Code references
Grounded in the retrieved California Fire Code — click a citation to read the verbatim passage:
CFC § 102.7 High relevance — show source text
Chapters 68 through 79 Reserved for future use.
PART VI—REFERENCED STANDARDS
Chapter 80 Referenced Standards
Chapter 80 lists all of the product and installation standards and codes that are referenced throughout Chapters 1 through 67 and includes identification of the promulgators and the section numbers in which the standards and codes are referenced. As stated in Section 102.7, these standards and codes become an enforceable part of the code (to the prescribed extent of the reference) as if printed in the body of the code.
PART VII—APPENDICES
Appendix Chapter 4 Special Detailed Requirements Based on Use and Occupancy
Appendix Chapter 4 provides detailed criteria for special uses and occupancies. The unique characteristics of a live/work unit as opposed to a 30-story high-rise building call for specific standards for each. Twenty-seven sections address covered and open mall buildings, atri- ums, hospitals, stages, buildings where hazardous materials are used and stored, jails and prisons, ambulatory care facilities and storm shelters, among other special occupancy issues.
Appendix A Board of Appeals
Appendix A contains the provisions for appeal and the establishment of a board of appeals. The provisions include the application for an appeal, the makeup of the board of appeals and the conduct of the appeal process.
Appendix B Fire-Flow Requirements for Buildings
Appendix B provides a tool for the use of jurisdictions in establishing a policy for determining fire-flow requirements in accordance with Section 507.3. The primary tool used in this appendix is a table that presents fire flow based on construction type and building area based on the correlation of the Insurance Services Office (ISO) method and the construction types used in the CBC.
Appendix BB Fire-flow Requirements for Buildings
The procedures determining fire-flow requirements for any school buildings or portions of buildings hereafter constructed for which review and approval is required under Subdivision(a) of Section 17280 of the Government Code shall be in accordance with this appendix as amended by the state fire marshal.
Appendix C Fire Hydrant Locations and Distribution
Appendix C focuses on the location and spacing of fire hydrants, which is important to the success of firefighting operations. This particular appendix gives one methodology based on the required fire flow that fire departments can work with to set a policy for hydrant distribution around new buildings and facilities in conjunction with Section 507.5.
Appendix CC Fire Hydrant Locations and Distribution
Fire hydrants shall be provided in accordance with this appendix for the protection of any school buildings, or portions thereof, hereafter constructed for which review and approval are required under Subdivision(a) of Section 17280 of the Government Code.
Appendix D Fire Apparatus Access Roads
Appendix D contains more detailed elements for use with the basic access requirements found in Section 503. This appendix, like Appendices B and C, is a tool for jurisdictions looking for guidance in establishing access requirements and includes criteria for multiple-family residential developments, large one- and two-family subdivisions, specific examples for various types of turnarounds for fire department apparatus and parking regulatory signage.
Appendix E Hazard Categories
Appendix E contains guidance in the classifying of hazardous materials so that proposed designs can be evaluated intelligently and accurately. The descriptive materials and explanations of hazardous materials and how to report and evaluate them on a Safety Data Sheet (SDS) are intended to be instructional as well as informative.
Appendix F Hazard Ranking
California Fire Code High relevance — show source text
APPENDIX A BOARD OF APPEALS . . . . . . . . . . . APPENDIX A-3
A101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-3
APPENDIX B FIRE-FLOW REQUIREMENTS FOR
BUILDINGS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX B-3
B101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX B-3
B102 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX B-3
B103 Modifications . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX B-3
B104 Fire-Flow Calculation Area . . . . . . . . . . . . APPENDIX B-3
B105 Fire-Flow Requirements for Buildings . . APPENDIX B-3
B106 Referenced Standards . . . . . . . . . . . . . . . . APPENDIX B-5
APPENDIX BB FIRE-FLOW REQUIREMENTS FOR BUILDINGS . . . . . . . . . . . . . . . . . . . . . . . . .APPENDIX BB-3
BB101 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX BB-3 BB102 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX BB-3
BB103 Modifications . . . . . . . . . . . . . . . . . . . . . . . APPENDIX BB-3
BB104 Fire Area . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX BB-3
BB105 Fire-Flow Requirements for Buildings . . . . . . . . . . . . . . . . . . . . . . APPENDIX BB-3
APPENDIX C FIRE HYDRANT LOCATIONS AND
DISTRIBUTION . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX C-3
C101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX C-3
C102 Number of Fire Hydrants . . . . . . . . . . . . . . APPENDIX C-3 C103 Fire Hydrant Spacing . . . . . . . . . . . . . . . . . APPENDIX C-4 C104 Consideration of Existing Fire Hydrants. . . . . . . . . . . . . . . . APPENDIX C-4 C105 Referenced Standard . . . . . . . . . . . . . . . . . APPENDIX C-4
APPENDIX CC FIRE HYDRANT LOCATIONS AND
CFC § 507.3. High relevance — show source text
1(1)|||X||||||||||||||||||||| |B105.2|||X|||||||||||||||||||||
- The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Fire Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same.
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APPENDIX B-2 2025 CALIFORNIA FIRE CODE
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B FIRE-FLOW REQUIREMENTS FOR BUILDINGS
The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance or legislation of the jurisdiction.
User notes:
About this appendix: Appendix B provides a tool for the use of jurisdictions in establishing a policy for determining fire-flow requirements in accordance with Section 507.3. The determination of required fire flow is not an exact science, but having some level of information provides a consistent way of choosing the appropriate fire flow for buildings throughout a jurisdiction. The primary tool used in this appendix is a table that presents fire flow based on construction type and building area based on the correlation of the Insurance Services Office (ISO) method and the construction types used in the California Building Code .
ICC code development note: Code change proposals to this appendix will be considered by the IFC Code Development Committee during the 2024 (Group A) Code Development Cycle.
SECTION B101—GENERAL
B101.1 Scope. The procedure for determining fire-flow requirements for buildings or portions of buildings hereafter constructed shall be in accordance with this appendix. This appendix does not apply to structures other than buildings.
SECTION B102—DEFINITIONS
B102.1 Definitions. For the purpose of this appendix, certain terms are defined as follows:
FIRE FLOW. The flow rate of a water supply, measured at 20 pounds per square inch (psi) (138 kPa) residual pressure, that is available for firefighting. FIRE-FLOW CALCULATION AREA. The floor area, in square feet (m [2] ), used to determine the required fire flow.
SECTION B103—MODIFICATIONS
B103.1 Decreases. The fire code official is authorized to reduce the fire-flow requirements for isolated buildings or a group of buildings in rural areas or small communities where the development of full fire-flow requirements is impractical.
B103.2 Increases. The fire code official is authorized to increase the fire-flow requirements where conditions indicate an unusual susceptibility to group fires or conflagrations. An increase shall be not more than twice that required for the building under consideration.
B103.3 Areas without water supply systems. For information regarding water supplies for firefighting purposes in rural and suburban areas in which adequate and reliable water supply systems do not exist, the fire code official is authorized to utilize NFPA 1142 or the California Wildland-Urban Interface Code .
SECTION B104—FIRE-FLOW CALCULATION AREA
B104.1 General. The fire-flow calculation area shall be the total floor area of all floor levels within the exterior walls, and under the horizontal projections of the roof of a building.
CFC § 137.9 High relevance — show source text
- The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Fire Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same.
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APPENDIX BB-2 2025 CALIFORNIA FIRE CODE
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BB FIRE-FLOW REQUIREMENTS FOR BUILDINGS
SECTION BB101—SCOPE
BB101.1 The procedures determining fire-flow requirements for any school buildings or portions of buildings hereafter constructed for which review and approval is required under Subdivision(a) of Section 17280 of the Government Code shall be in accordance with this appendix as amended by the state fire marshal. This appendix does not apply to structures other than buildings.
SECTION BB102—DEFINITIONS
BB102.1 For the purpose of Appendix III-A, certain terms are defined as follows:
FIRE AREA. The floor area, in square feet, used to determine the required fire flow.
FIRE FLOW. The flow rate of a water supply, measured at 20 psi (137.9 kPa) residual pressure, that is available for firefighting.
SECTION BB103—MODIFICATIONS
BB103.1 An alternative method of providing water for fire protection or any other alternative, in lieu of providing the water, may be enforced when deemed appropriate by the fire chief and the state fire marshal.
SECTION BB104—FIRE AREA
BB104.1 General. The fire area shall be the total floor area of all floor levels within the exterior walls, and under the horizontal projec- tions of the roof of a building, except as modified in Section 4.
BB104.2 Area separation. Portions of buildings which are separated by one or more 4-hour area separation walls constructed in accor- dance with the building code, without openings and provided with a 30-inch (762 mm) parapet, are allowed to be considered as separate fire areas.
BB104.3 Type I and Type IB construction. The fire area of buildings constructed of Type I and Type IB construction shall be the area of the three largest successive floors.
SECTION BB105—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
BB105.1 The minimum fire flow and flow duration for school buildings shall be as specified in Table BB105.1.
Exception: A reduction in required fire flow of up to 75 percent is allowed when the building is provided with an approved automatic sprinkler system. When a reduction in fire flow is used, fire flow shall not be less than 1500 GPM.
2025 CALIFORNIA FIRE CODE APPENDIX BB-3
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APPENDIX BB—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
|TABLE BB105.
CFC § 102.7 High relevance — show source text
Chapter 65 addresses the significant hazards associated with pyroxylin (cellulose nitrate) plastics, which are the most dangerous and unstable of all plastic compounds. Strict compliance with the provisions of this chapter, along with proper housekeeping and storage arrangements, helps to reduce the hazards associated with pyroxylin (cellulose nitrate) plastics in a fire or other emergencies.
Chapter 66 Unstable (Reactive) Materials
Chapter 66 addresses the hazards of unstable (reactive) liquid and solid materials as well as unstable (reactive) compressed gases. Materials that pose multiple hazards, such as toxicity, corrosivity, explosivity, flammability or oxidizing potential, must conform to the requirements of the code with respect to all hazards. Strict compliance with the provisions of this chapter, along with proper housekeeping and storage arrangements, help reduce the exposure hazards associated with unstable (reactive) materials in a fire or other emergency.
Chapter 67 Water-Reactive Solids and Liquids
Chapter 67 addresses the hazards associated with water-reactive materials that are solid or liquid at normal temperatures and pressures. In addition to their water reactivity, these materials may pose a wide range of other hazards, such as toxicity, flammability, corrosiveness or oxidizing potential. Strict compliance with the requirements of this chapter, along with proper housekeeping and storage arrangements, helps to reduce the exposure hazards associated with water-reactive materials in a fire or other emergency.
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Chapters 68 through 79 Reserved for future use.
PART VI—REFERENCED STANDARDS
Chapter 80 Referenced Standards
Chapter 80 lists all of the product and installation standards and codes that are referenced throughout Chapters 1 through 67 and includes identification of the promulgators and the section numbers in which the standards and codes are referenced. As stated in Section 102.7, these standards and codes become an enforceable part of the code (to the prescribed extent of the reference) as if printed in the body of the code.
PART VII—APPENDICES
Appendix Chapter 4 Special Detailed Requirements Based on Use and Occupancy
Appendix Chapter 4 provides detailed criteria for special uses and occupancies. The unique characteristics of a live/work unit as opposed to a 30-story high-rise building call for specific standards for each. Twenty-seven sections address covered and open mall buildings, atri- ums, hospitals, stages, buildings where hazardous materials are used and stored, jails and prisons, ambulatory care facilities and storm shelters, among other special occupancy issues.
Appendix A Board of Appeals
Appendix A contains the provisions for appeal and the establishment of a board of appeals. The provisions include the application for an appeal, the makeup of the board of appeals and the conduct of the appeal process.
Appendix B Fire-Flow Requirements for Buildings
Appendix B provides a tool for the use of jurisdictions in establishing a policy for determining fire-flow requirements in accordance with Section 507.3. The primary tool used in this appendix is a table that presents fire flow based on construction type and building area based on the correlation of the Insurance Services Office (ISO) method and the construction types used in the CBC.
Appendix BB Fire-flow Requirements for Buildings
CFC § 507.5. High relevance — show source text
Appendix BB Fire-flow Requirements for Buildings
The procedures determining fire-flow requirements for any school buildings or portions of buildings hereafter constructed for which review and approval is required under Subdivision(a) of Section 17280 of the Government Code shall be in accordance with this appendix as amended by the state fire marshal.
Appendix C Fire Hydrant Locations and Distribution
Appendix C focuses on the location and spacing of fire hydrants, which is important to the success of firefighting operations. This particular appendix gives one methodology based on the required fire flow that fire departments can work with to set a policy for hydrant distribution around new buildings and facilities in conjunction with Section 507.5.
Appendix CC Fire Hydrant Locations and Distribution
Fire hydrants shall be provided in accordance with this appendix for the protection of any school buildings, or portions thereof, hereafter constructed for which review and approval are required under Subdivision(a) of Section 17280 of the Government Code.
Appendix D Fire Apparatus Access Roads
Appendix D contains more detailed elements for use with the basic access requirements found in Section 503. This appendix, like Appendices B and C, is a tool for jurisdictions looking for guidance in establishing access requirements and includes criteria for multiple-family residential developments, large one- and two-family subdivisions, specific examples for various types of turnarounds for fire department apparatus and parking regulatory signage.
Appendix E Hazard Categories
Appendix E contains guidance in the classifying of hazardous materials so that proposed designs can be evaluated intelligently and accurately. The descriptive materials and explanations of hazardous materials and how to report and evaluate them on a Safety Data Sheet (SDS) are intended to be instructional as well as informative.
Appendix F Hazard Ranking
The information in Appendix F is intended to be a companion to the specific requirements of Chapters 51 through 67, which regulate the storage, handling and use of all hazardous materials classified as either physical or health hazards. This appendix lists the various hazardous materials categories that are defined in this code, along with the NFPA 704 hazard ranking for each.
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Appendix G Cryogenic Fluids—Weight and Volume Equivalents
Appendix G gives the fire code official and design professional a ready reference tool for the conversion of the liquid weight and volume of cryogenic fluid to their corresponding volume of gas and vice versa and is a companion to the provisions of Chapter 55 of this code. Note that this appendix is for information purposes and is not intended for adoption.
Appendix H Hazardous Materials Management Plan (HMMP) and Hazardous Materials Inventory Statement (HMIS) Instructions
Appendix H is intended to assist businesses in establishing a Hazardous Materials Management Plan (HMMP) and Hazardous Materials Inventory Statement (HMIS) based on the classification and quantities of materials that would be found on-site, in storage or in use. The sample forms and available Safety Data Sheets (SDS) provide the basis for the evaluations. It is also a companion to CFC Sections 407.5 and 407.6, which provide the requirement that the HMIS and HMMP be submitted when required by the fire code official.
Appendix I Fire Protection Systems—Noncompliant Conditions
CFC § 507.3. High relevance — show source text
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Adopting Agency BSC BSC-
CGSFM Col5 HCD Col7 Col8 DSA Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting Agency BSC BSC-
CGT-24 T-19* 1 2 1/AC AC SS 1 1R 2 3 4 5 5 5 5 5 5 5 5 5 Adopt Entire Chapter Adopt Entire Chapter as
amended (amended sections
listed below)X Adopt only those sections that
are listed below[California Code of Regulations,
Title 19, Division 1]Chapter / Section Table B105.1(1) X B105.2 X - The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Fire Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same.
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APPENDIX B-2 2025 CALIFORNIA FIRE CODE
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B FIRE-FLOW REQUIREMENTS FOR BUILDINGS
The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance or legislation of the jurisdiction.
User notes:
About this appendix: Appendix B provides a tool for the use of jurisdictions in establishing a policy for determining fire-flow requirements in accordance with Section 507.3. The determination of required fire flow is not an exact science, but having some level of information provides a consistent way of choosing the appropriate fire flow for buildings throughout a jurisdiction. The primary tool used in this appendix is a table that presents fire flow based on construction type and building area based on the correlation of the Insurance Services Office (ISO) method and the construction types used in the California Building Code .
ICC code development note: Code change proposals to this appendix will be considered by the IFC Code Development Committee during the 2024 (Group A) Code Development Cycle.
SECTION B101—GENERAL
CFC § 701-30 High relevance — show source text
SECTION BB104—FIRE AREA
BB104.1 General. The fire area shall be the total floor area of all floor levels within the exterior walls, and under the horizontal projec- tions of the roof of a building, except as modified in Section 4.
BB104.2 Area separation. Portions of buildings which are separated by one or more 4-hour area separation walls constructed in accor- dance with the building code, without openings and provided with a 30-inch (762 mm) parapet, are allowed to be considered as separate fire areas.
BB104.3 Type I and Type IB construction. The fire area of buildings constructed of Type I and Type IB construction shall be the area of the three largest successive floors.
SECTION BB105—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
BB105.1 The minimum fire flow and flow duration for school buildings shall be as specified in Table BB105.1.
Exception: A reduction in required fire flow of up to 75 percent is allowed when the building is provided with an approved automatic sprinkler system. When a reduction in fire flow is used, fire flow shall not be less than 1500 GPM.
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APPENDIX BB—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
TABLE BB105.1—MINIMUM REQUIRED FIRE-FLOW AND FLOW DURATION FOR BUILDINGS Col2 Col3 Col4 Col5 Col6 Col7 FIRE AREA (square feet) FIRE AREA (square feet) FIRE AREA (square feet) FIRE AREA (square feet) FIRE AREA (square feet) FIRE-FLOW
(gallons per
minute)bFLOW
DURATION
(hours)Type IA and IB a Type IIA and IIIA a Type IV and V-A a Type IIB and IIIB a Type V-B a Type V-B a Type V-B a 0-22,700 0-12,700 0-8,200 0-5,900 0-3,600 1,500 2 22,701-30,200 12,701-17,000 8,201-10,900 5,901-7,900 3,601-4,800 1,750 1,750 30,201-38,700 17,001-21,800 10,901-12,900 7,901-9,800 4,801-6,200 2,000 2,000 38,701-48,300 21,801-24,200 12,901-17,400 9,801-12,600 6,201-7,700 2,250 _2, CFC § 137.9 High relevance — show source text
CALIFORNIA FIRE CODE – MATRIX ADOPTION TABLE
APPENDIX BB – FIRE-FLOW REQUIREMENTS FOR BUILDINGS
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Adopting Agency BSC BSC-
CGSFM Col5 HCD Col7 Col8 DSA Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting Agency BSC BSC-
CGT-24 T-19* 1 2 1/AC AC SS 1 1R 2 3 4 5 5 5 5 5 5 5 5 5 Adopt Entire Chapter X Adopt Entire Chapter as
amended (amended sections
listed below)Adopt only those sections that
are listed below[California Code of Regulations,
Title 19, Division 1]Chapter / Section - The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Fire Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same.
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APPENDIX BB-2 2025 CALIFORNIA FIRE CODE
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BB FIRE-FLOW REQUIREMENTS FOR BUILDINGS
SECTION BB101—SCOPE
BB101.1 The procedures determining fire-flow requirements for any school buildings or portions of buildings hereafter constructed for which review and approval is required under Subdivision(a) of Section 17280 of the Government Code shall be in accordance with this appendix as amended by the state fire marshal. This appendix does not apply to structures other than buildings.
SECTION BB102—DEFINITIONS
BB102.1 For the purpose of Appendix III-A, certain terms are defined as follows:
FIRE AREA. The floor area, in square feet, used to determine the required fire flow.
FIRE FLOW. The flow rate of a water supply, measured at 20 psi (137.9 kPa) residual pressure, that is available for firefighting.
SECTION BB103—MODIFICATIONS
CWUIC § B101 Medium relevance — show source text
SECTION B101—GENERAL
B101.1 Scope. The procedure for determining fire-flow requirements for buildings or portions of buildings hereafter constructed shall be in accordance with this appendix. This appendix does not apply to structures other than buildings.
SECTION B102—DEFINITIONS
B102.1 Definitions. For the purpose of this appendix, certain terms are defined as follows:
FIRE FLOW. The flow rate of a water supply, measured at 20 pounds per square inch (psi) (138 kPa) residual pressure, that is available for firefighting. FIRE-FLOW CALCULATION AREA. The floor area, in square feet (m [2] ), used to determine the required fire flow.
SECTION B103—MODIFICATIONS
B103.1 Decreases. The fire code official is authorized to reduce the fire-flow requirements for isolated buildings or a group of buildings in rural areas or small communities where the development of full fire-flow requirements is impractical.
B103.2 Increases. The fire code official is authorized to increase the fire-flow requirements where conditions indicate an unusual susceptibility to group fires or conflagrations. An increase shall be not more than twice that required for the building under consideration.
B103.3 Areas without water supply systems. For information regarding water supplies for firefighting purposes in rural and suburban areas in which adequate and reliable water supply systems do not exist, the fire code official is authorized to utilize NFPA 1142 or the California Wildland-Urban Interface Code .
SECTION B104—FIRE-FLOW CALCULATION AREA
B104.1 General. The fire-flow calculation area shall be the total floor area of all floor levels within the exterior walls, and under the horizontal projections of the roof of a building.
Exceptions:
The fire-flow calculation area of buildings constructed of Types IA and IB construction shall be the area of the three largest successive floors.
The fire-flow calculation area for open parking garages of Types IA and IB construction shall be determined by the area of the largest floor.
B104.2 Area separation. Portions of buildings that are separated by fire walls without openings, constructed in accordance with the California Building Code, are allowed to be considered as separate fire-flow calculation areas.
SECTION B105—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
B105.1 One- and two-family dwellings, Group R-3 and R-4 buildings and townhouses. The minimum fire-flow and flow duration requirements for one- and two-family dwellings, Group R-3 and R-4 buildings and townhouses shall be as specified in Tables B105.1(1) and B105.1(2).
2025 CALIFORNIA FIRE CODE APPENDIX B-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX B—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
|TABLE B105.1(1)—REQUIRED FIRE FLOW FOR ONE- AND
TWO-FAMILY DWELLINGS,CFC § 1274.04 Medium relevance — show source text
or otherwise posted to provide for unobstructed visibility from that_ intersection.
(f) In all cases, the address shall be posted at the beginning of construction and shall be maintained thereafter.
[CCR, Title 14 §1274.04]
SECTION 404—WATER SUPPLY
404.1 General. An approved water source shall have an adequate water supply for the use of the fire protection service to protect buildings and structures from exterior fire sources or to suppress structure fires within the wildland-urban interface area of the jurisdiction in accordance with this section.
404.2 Required water supply. An approved water supply capable of supplying the required fire flow for structural fire protection and wildland fire exposure shall be provided to the premises on which facilities, buildings or portions of buildings are hereafter constructed or moved into or within the jurisdiction in accordance with Section 507 of the California Fire Code.
404.3 Draft sites. Approved draft sites shall be provided at natural water sources intended for use as fire protection for compliance with this code. The design, construction, location, access and access maintenance of draft sites shall be approved by the code official.
404.3.1 Access. The draft site shall have emergency vehicle access from an access road in accordance with Section 403.
404.3.2 Pumper access points. The pumper access point shall be either an emergency vehicle access area alongside a conforming access road or an approved driveway not longer than 150 feet (45 720 mm). Pumper access points and access driveways shall be designed and constructed in accordance with all codes and ordinances enforced by this jurisdiction. Pumper access points shall not require the pumper apparatus to obstruct a road or driveway.
404.4 Hydrants. Hydrants shall be designed and constructed in accordance with nationally recognized standards. The location and access shall be approved by the code official. The number and spacing of fire hydrants shall be in accordance with Appendix C or CC of the California Fire Code, as applicable.
404.5 Adequate water supply. Fire-flow requirements shall be determined in accordance with Appendix B or BB of the California Fire Code, as applicable.
404.6 Reserved.
404.7 Obstructions. Access to water sources required by this code shall be unobstructed at all times. The fire department shall not be deterred or hindered from gaining immediate access to water source equipment, fire protection equipment or hydrants.
404.8 Identification. Water sources, draft sites, hydrants and fire protection equipment and hydrants shall be clearly identified in a manner approved by the code official to identify location and to prevent obstruction by parking and other obstructions. Each fire hydrant and access to a water supply shall be identified in accordance with one of the following: 1. Where located along a driveway, a reflectorized blue marker with a minimum dimension of 3 inches (73 mm) shall be located on the driveway address sign and mounted on a fire-retardant post. 2. Where located along an access road: 2.2. A reflectorized blue marker with a minimum dimension of 3 inches (73 mm) shall be mounted on a fire-retardant post. The signpost shall be within 3 feet (914 mm) of said fire hydrant with the sign not less than 3 feet (914 mm) nor greater than 5 feet (1524 mm) above ground, in a horizontal position and visible from the driveway. _2.3.
CFC § 903.3.1.3 Medium relevance — show source text
SECTION B104—FIRE-FLOW CALCULATION AREA
B104.1 General. The fire-flow calculation area shall be the total floor area of all floor levels within the exterior walls, and under the horizontal projections of the roof of a building.
Exceptions:
The fire-flow calculation area of buildings constructed of Types IA and IB construction shall be the area of the three largest successive floors.
The fire-flow calculation area for open parking garages of Types IA and IB construction shall be determined by the area of the largest floor.
B104.2 Area separation. Portions of buildings that are separated by fire walls without openings, constructed in accordance with the California Building Code, are allowed to be considered as separate fire-flow calculation areas.
SECTION B105—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
B105.1 One- and two-family dwellings, Group R-3 and R-4 buildings and townhouses. The minimum fire-flow and flow duration requirements for one- and two-family dwellings, Group R-3 and R-4 buildings and townhouses shall be as specified in Tables B105.1(1) and B105.1(2).
2025 CALIFORNIA FIRE CODE APPENDIX B-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX B—FIRE-FLOW REQUIREMENTS FOR BUILDINGS
TABLE B105.1(1)—REQUIRED FIRE FLOW FOR ONE- AND
TWO-FAMILY DWELLINGS, GROUP R-3 AND R-4 BUILDINGS AND TOWNHOUSESCol2 Col3 Col4 FIRE-FLOW
CALCULATION AREA
(square feet)AUTOMATIC
SPRINKLER SYSTEM
(Design Standard)MINIMUM
FIRE FLOW
(gallons per minute)FLOW
DURATION
(hours)0–3,600 No automatic sprinkler system 1,000 1 3,601 and greater No automatic sprinkler system Value in Table B105.1(2) Duration in Table B105.1(2) at
the required fire-flow rate0–3,600 Section 903.3.1.3 of the_California Fire Code_ or
Section P2904 of the_California Residential Code_500 1/2 3,601 and greater Section 903.3.1.3 of the_California Fire Code_ or
Section P2904 of the_California Residential Code_1/2 value in Table B105.1(2) 1 For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m. For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m. For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m. For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m. |TABLE B105.1(2)—REFERENCE TABLE FOR TABLES B105.1(1) AND B105.
Frequently asked questions
How do I know whether to use Appendix B or BB?
Use Appendix BB when the project is a school building under the State Fire Marshal’s review authority; otherwise use Appendix B or another approved method per § 507.3.
If my building is sprinklered, can I always reduce the required fire flow?
Not always. The appendices allow specified reductions, but they include minimums (e.g., Appendix BB’s reduced flow shall not be less than 1500 gpm). Also the water supply must still meet the greater of sprinkler demand or the table value. § BB105.1 (Exception); § B105.3.
What area is used to look up the table value?
The fire‑flow calculation area or fire area is the total floor area within the exterior walls (all levels). For certain construction types (Type I/IB) use the three largest successive floors. § B104.1; § BB104.1 / BB104.3.
Can the fire code official change the table result for my site?
Yes. The fire code official may reduce requirements for isolated/rural buildings or increase them (up to twice the table value) where unusual risk exists. § B103.1 / § B103.2.
Where do I find the exact gpm numbers for a non‑residential building?
Appendix B’s numeric lookup is in the B105 series tables (not all table rows were reproduced here). You must consult the adopted CFC Appendix B tables (Table B105.1(2), Table B105.2, etc.) in your jurisdiction’s code book or the official CFC document. § B105.2 explains how those table values are used.
More in California Fire Code
- Administration and Definitions
- General Requirements and Emergency Planning
- Fire Service Features and Fire Department Access
- Referenced Standards and Adoptable Appendices (Chapter 80; Appendices A–Q)
- Fire and Smoke Protection Features (fire‑resistance, barriers)
- Interior Finish, Decorative Materials and Furnishings
- Fire Protection and Life‑Safety Systems (sprinklers, alarms, smoke control)
- Means of Egress (exit design and maintenance)
- Construction Requirements for Existing Buildings (retrofit rules)
- Energy Systems and Stationary Energy Storage (ESS)
- Special Occupancies and Operations (chapters 20–41, 48–49)
- Hazardous Materials — Storage, Use and Handling (Chapters 50–67)
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