The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance.
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 fire fighting.
FIRE-FLOW CALCULATION AREA. The floor area, in square feet (m2), used to determine the required fire flow.
Section B103 Modifications
B103.1 Decreases
The fire chief 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 chief is authorized to increase the fire-flow requirements where conditions indicate an unusual susceptibility to group fires or conflagrations. An increase shall not be more than twice that required for the building under consideration.
B103.3 Areas Without Water Supply Systems
For information regarding water supplies for fire-fighting 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 International 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, except as modified in Section B104.3.
B104.2 Area Separation
Portions of buildings which are separated by fire walls without openings, constructed in accordance with the International Building Code, are allowed to be considered as separate fire-flow calculation areas.
B104.3 Type IA and Type IB Construction
The fire-flow calculation area of buildings constructed of Type IA and Type IB construction shall be the area of the three largest successive floors.
Exception: Fire-flow calculation area for open parking garages shall be determined by the area of the largest floor.
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).
| 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 rate |
| 0-3,600 | Section 903.3.1.3 of the International Fire Code or Section P2904 of the International Residential Code | 500 | 1/2 |
| 3,601 and greater | Section 903.3.1.3 of the International Fire Code or Section P2904 of the International 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.
| FIRE-FLOW CALCULATION AREA (square feet) | FIRE-FLOW (gallons per minute)b | FLOW DURATION (hours) | ||||
| Type IA and IBa | Type IIA and IIIAa | Type IV and V-Aa | Type IIB and IIIBa | Type V-Ba | ||
| 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 | |
| 30,201-38,700 | 17,001-21,800 | 10,901-12,900 | 7,901-9,800 | 4,801-6,200 | 2,000 | |
| 38,701-48,300 | 21,801-24,200 | 12,901-17,400 | 9,801-12,600 | 6,201-7,700 | 2,250 | |
| 48,301-59,000 | 24,201-33,200 | 17,401-21,300 | 12,601-15,400 | 7,701-9,400 | 2,500 | |
| 59,001-70,900 | 33,201-39,700 | 21,301-25,500 | 15,401-18,400 | 9,401-11,300 | 2,750 | |
| 70,901-83,700 | 39,701-47,100 | 25,501-30,100 | 18,401-21,800 | 11,301-13,400 | 3,000 | 3 |
| 83,701-97,700 | 47,101-54,900 | 30,101-35,200 | 21,801-25,900 | 13,401-15,600 | 3,250 | |
| 97,701-112,700 | 54,901-63,400 | 35,201-40,600 | 25,901-29,300 | 15,601-18,000 | 3,500 | |
| 112,701-128,700 | 63,401-72,400 | 40,601-46,400 | 29,301-33,500 | 18,001-20,600 | 3,750 | |
| 128,701-145,900 | 72,401-82,100 | 46,401-52,500 | 33,501-37,900 | 20,601-23,300 | 4,000 | 4 |
| 145,901-164,200 | 82,101-92,400 | 52,501-59,100 | 37,901-42,700 | 23,301-26,300 | 4,250 | |
| 164,201-183,400 | 92,401-103,100 | 59,101-66,000 | 42,701-47,700 | 26,301-29,300 | 4,500 | |
| 183,401-203,700 | 103,101-114,600 | 66,001-73,300 | 47,701-53,000 | 29,301-32,600 | 4,750 | |
| 203,701-225,200 | 114,601-126,700 | 73,301-81,100 | 53,001-58,600 | 32,601-36,000 | 5,000 | |
| 225,201-247,700 | 126,701-139,400 | 81,101-89,200 | 58,601-65,400 | 36,001-39,600 | 5,250 | |
| 247,701-271,200 | 139,401-152,600 | 89,201-97,700 | 65,401-70,600 | 39,601-43,400 | 5,500 | |
| 271,201-295,900 | 152,601-166,500 | 97,701-106,500 | 70,601-77,000 | 43,401-47,400 | 5,750 | |
| 295,901-Greater | 166,501-Greater | 106,501-115,800 | 77,001-83,700 | 47,401-51,500 | 6,000 | |
| — | — | 115,801-125,500 | 83,701-90,600 | 51,501-55,700 | 6,250 | |
| — | — | 125,501-135,500 | 90,601-97,900 | 55,701-60,200 | 6,500 | |
| — | — | 135,501-145,800 | 97,901-106,800 | 60,201-64,800 | 6,750 | |
| — | — | 145,801-156,700 | 106,801-113,200 | 64,801-69,600 | 7,000 | |
| — | — | 156,701-167,900 | 113,201-121,300 | 69,601-74,600 | 7,250 | |
| — | — | 167,901-179,400 | 121,301-129,600 | 74,601-79,800 | 7,500 | |
| — | — | 179,401-191,400 | 129,601-138,300 | 79,801-85,100 | 7,750 | |
| — | — | 191,401-Greater | 138,301-Greater | 85,101-Greater | 8,000 | |
For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m, 1 pound per square inch = 6.895 kPa.
- Types of construction are based on the International Building Code.
- Measured at 20 psi residual pressure.
B105.2 Buildings Other Than One- And Two-Family Dwellings, Group R-3 and R-4 Buildings and Townhouses
The minimum fire-flow and flow duration for buildings other than one- and two-family dwellings, Group R-3 and R-4 buildings and townhouses shall be as specified in Tables B105.2 and B105.1(2).
| AUTOMATIC SPRINKLER SYSTEM (Design Standard) | MINIMUM FIRE-FLOW (gallons per minute) | FLOW DURATION (hours) |
| No automatic sprinkler system | Value in Table B105.1(2) | Duration in Table B105.1(2) |
| Section 903.3.1.1 of the International Fire Code | 25% of the value in Table B105.1(2)a | Duration in Table B105.1(2) at the reduced flow rate |
| Section 903.3.1.2 of the International Fire Code | 25% of the value in Table B105.1(2)b | Duration in Table B105.1(2) at the reduced flow rate |
For SI: 1 gallon per minute = 3.785 L/m.
- The reduced fire-flow shall be not less than 1,000 gallons per minute.
- The reduced fire-flow shall be not less than 1,500 gallons per minute.
B105.3 Water Supply for Buildings Equipped With an Automatic Sprinkler System
For buildings equipped with an approved automatic sprinkler system, the water supply shall be capable of providing the greater of:
- The automatic sprinkler system demand, including hose stream allowance.
- The required fire-flow.
Section B106 Referenced Standards
| ICC | IBC—15 | International Building Code | B104.2 |
| ICC | IFC—15 | International Fire Code | Tables B105.1.(1) and B105.2 |
| ICC | IWUIC—15 | International Wildland-Urban Interface Code | B103.3 |
| ICC | IRC—15 | International Residential Code | Table B105.1.(1) |
| NFPA | 1142—12 | Standard on Water Supplies for Suburban and Rural Fire Fighting | B103.3 |
