IS 1641:1988 is the Indian Standard (BIS) for fire safety of buildings (general: general principles of fire grading and classification). This code establishes the general principles of fire grading and classification of buildings based on occupancy and fire load. It sets the criteria for the fire resistance ratings of structural elements and categorizes building construction into four distinct types based on their fire endurance. It acts as the foundational framework for passive fire safety design in India.
Establishes general principles for fire grading, classification, and basic fire safety measures in buildings.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Primary Unit for Fire Resistance | Hours | Hours | NFPA 101 / IBC |
| Basis for Fire Resistance Requirement | Fire load classification (Low, Moderate, High) based on combustible contents in kcal/m². | Predetermined by Occupancy Group and Construction Type in code tables (e.g., Table 601 in IBC). | IBC Chapter 6 |
| Example Residential Classification | Group A: Residential Buildings | Group R: Residential Occupancies | IBC Chapter 3 |
| Example Assembly Classification | Group D: Assembly Buildings (for congregation of 50 or more persons) | Group A: Assembly (for congregation of 50 or more persons) | IBC Chapter 3 |
| Construction Type Classification | Type 1, 2, 3, 4 (Defined in National Building Code based on IS 1641 principles) | Type I, II, III, IV, V (with A/B sub-classifications for protected/unprotected) | IBC Chapter 6 |
| Standard Fire Resistance Test | IS 1642 (based on time-temperature curve) | ASTM E119 (Standard Test Methods for Fire Tests of Building Construction and Materials) | NFPA / IBC |
| Highest Standard Fire Rating | 4 hours | 4 hours (for specific high-risk separations, e.g., fire walls) | IBC Chapter 7 |