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IS 15105:2002 is the Indian Standard (BIS) for design and installation of fixed automatic sprinkler fire extinguishing systems - code of practice. This code provides comprehensive guidelines for the design, installation, and maintenance of fixed automatic sprinkler fire extinguishing systems in buildings. It details the classification of fire hazards, requirements for water supplies, component specifications, system layout principles, and testing procedures to ensure system reliability.
Design and Installation of Fixed Automatic Sprinkler Fire Extinguishing Systems - Code of Practice
Quick Reference — Top IS 15105:2002 Values
Key design parameters including hazard classifications, design densities, sprinkler spacing, area coverage, water supply duration, and system test pressures.
✓ Verified 2026-04-27
Reference
Value
Clause
Design Density - Light Hazard— Minimum discharge density over the area of operation.
2.25 mm/min
Cl. 6.2.2 (Table 4)
Assumed Area of Operation - Light Hazard— Maximum area assumed to be operating in a fire scenario.
84 m²
Cl. 6.2.2 (Table 4)
Design Density - Ordinary Hazard (OH1)— For occupancies like offices, restaurants, and schools.
5.0 mm/min
Cl. 6.2.2 (Table 4)
Assumed Area of Operation - Ordinary Hazard (OH1)— Increases for other OH groups (up to 360 m²).
72 m²
Cl. 6.2.2 (Table 4)
Design Density - High Hazard Process (HHP1)— For occupancies like aircraft hangars and chemical plants.
7.5 mm/min
Cl. 6.2.2 (Table 4)
Assumed Area of Operation - High Hazard Process (HHP1)
260 m²
Cl. 6.2.2 (Table 4)
Water Supply Duration - Light Hazard
30 min
Cl. 5.2 (Table 3)
Water Supply Duration - Ordinary Hazard
60 - 90 min
Cl. 5.2 (Table 3)
Water Supply Duration - High Hazard
90 min
Cl. 5.2 (Table 3)
Max. Area per Sprinkler - Light Hazard— For standard spray sprinklers.
21 m²
Cl. 6.4 (Table 5)
Max. Area per Sprinkler - Ordinary Hazard— For standard spray sprinklers.
12 m²
Cl. 6.4 (Table 5)
Max. Area per Sprinkler - High Hazard— For standard spray sprinklers.
9 m²
Cl. 6.4 (Table 5)
Max. Sprinkler Spacing - Light/Ordinary Hazard
4.6 m
Cl. 6.3.2 (Table 5)
Max. Sprinkler Spacing - High Hazard
3.7 m
Cl. 6.3.2 (Table 5)
Min. Sprinkler Spacing— To prevent cold soldering (sprinklers cooling each other).
2.0 m
Cl. 6.3.4
Max. Distance from Wall/Partition— e.g., 2.3 m for Light/Ordinary Hazard.
0.5 x Max. Spacing
Cl. 6.3.3
Min. Distance from Wall/Partition
100 mm
Cl. 6.3.3
Min. Clearance below Sprinkler Deflector— To allow for proper water distribution pattern.
300 mm
Cl. 6.5.2
Sprinkler Temp Rating - Ordinary— Colour Code: Red (Glass Bulb) or Uncoloured (Fusible Link).
68 °C
Cl. 4.6 (Table 2)
Sprinkler Temp Rating - Intermediate— Colour Code: Blue (Glass Bulb) or White (Fusible Link).
93 °C
Cl. 4.6 (Table 2)
Min. Running Pressure at any Sprinkler— Unless higher pressure is required to meet design density.
0.35 bar (5 psi)
Annex C, C-2.1
Hydrostatic Test Pressure— Whichever is higher. Pw = Max. working pressure.
15 bar or (Pw + 5 bar)
Cl. 9.2.2.1
Hydrostatic Test Duration
24 hours
Cl. 9.2.2.1
⚠ Verify against the latest BIS/IRC publication and project specifications. Amendment Slips may modify values.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! This 2002 version has been superseded by IS 15105:2021. The 2021 version should be used for all new projects and contains significant updates.
! Hydraulic calculations are mandatory for Ordinary Hazard (OH) and High Hazard (HH) systems. Pipe schedule tables can only be used for small Light Hazard (LH) systems.
! Careful coordination with architects and other MEP (Mechanical, Electrical, Plumbing) services is essential to ensure correct sprinkler placement and avoid clashes with ducts, lights, and structural members.
Standard for the Installation of Sprinkler Systems
Both standards provide comprehensive guidelines for the design, installation, and maintenance of automatic fire sprinkler systems.
BS EN 12845:2015+A1:2019BSI (UK) / CEN (Europe)
HighCurrent
Fixed firefighting systems — Automatic sprinkler systems — Design, installation and maintenance
Both codes cover the design, installation, and maintenance requirements for automatic sprinkler systems in buildings.
AS 2118.1:2017Standards Australia (AU)
HighCurrent
Automatic fire sprinkler systems, Part 1: General systems
Both standards detail requirements for the design and installation of general-purpose automatic fire sprinkler systems.
FMDS 2-0FM Global (US)
HighCurrent
Installation Guidelines for Automatic Sprinklers
Both provide detailed design and installation criteria, though FMDS is an insurance standard often with more stringent requirements.
Key Differences
≠Hazard Classification: IS 15105 categorizes high hazards into three groups (HHI, HHII, HHIII). NFPA 13 uses two groups for its equivalent 'Extra Hazard' classification (Group 1 and Group 2) and has separate, extensive chapters for various storage commodities, which are more detailed than the high hazard groups in the IS code.
≠Seismic Protection: NFPA 13 contains extensive, mandatory requirements for the seismic bracing and design of sprinkler systems in seismically active areas. IS 15105:2002 has significantly less detailed provisions for seismic protection, often deferring to general structural codes without specific guidance for sprinkler piping.
≠Residential Sprinklers: NFPA 13 provides specific criteria for residential sprinklers within a combined standard, and references NFPA 13R and 13D for other residential occupancies. IS 15105:2002 does not have a distinct or detailed classification and design criteria specifically for residential sprinklers, treating them under the 'Light Hazard' category.
≠Design Density/Area Curves: The specific values and shapes of the design density vs. area of operation curves differ. For a given hazard, NFPA 13 often requires a higher density over a smaller, more concentrated area compared to the curves provided in IS 15105.
Key Similarities
≈Hazard-Based Design Philosophy: Both standards are fundamentally based on classifying the occupancy hazard level (e.g., Light, Ordinary, High/Extra) to determine the required system performance, including water density and area of application.
≈Hydraulic Calculation Method: Both codes accept and are predominantly based on hydraulic calculations using the Hazen-Williams formula to determine pipe sizes and ensure adequate pressure and flow at the most remote sprinklers.
≈Core System Components: Both standards mandate a similar set of fundamental components for a complete system, including an approved water supply, control valves, a network of pipes, automatic sprinklers, and alarm devices (water flow and tamper switches).
≈Water Supply Duration: The required minimum duration for which the water supply must be available is similar for comparable hazard levels in both codes, typically ranging from 30 minutes for light hazard to 60-120 minutes for ordinary and high hazards.
Parameter Comparison
Parameter
IS Value
International
Source
Design Density (Ordinary Hazard - Group 2/II)
Typically 7.5 mm/min (from curve)
0.20 gpm/ft² (approx. 8.1 mm/min)
NFPA 13-22
Design Area (Ordinary Hazard - Group 2/II)
144 - 360 m² (from curve)
1500 ft² (approx. 139 m²)
NFPA 13-22
Maximum Sprinkler Spacing (Light Hazard, Standard Spray)
Light Hazard (LH), Ordinary Hazard (OH) divided into Groups I, II, and III, and High Hazard (HH) divided into Process and Storage categories. (Clause 5 & Table 1)
What is the maximum area a single sprinkler can cover in an Ordinary Hazard occupancy?+
12 m². (Table 3)
What is the minimum required duration for the water supply in a High Hazard (Process) system?+
120 minutes. (Table 2)
Can pipe schedules be used for designing a system for an office building?+
Generally no. Office buildings are typically classified as Ordinary Hazard, which requires hydraulic calculations. Pipe schedules are only for Light Hazard systems. (Clause 11.2)