IS 1641

: 1988

Code of practice for fire safety of buildings (General: General principles of fire grading and classification)

CurrentFrequently UsedCode of PracticeBIMFire Safety · Building Planning and Design
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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.

Quick Reference Values
Type 1 Construction Fire Resistance4 hours
Type 2 Construction Fire Resistance3 hours
Type 3 Construction Fire Resistance2 hours
Type 4 Construction Fire Resistance1 hour
Low Fire Load thresholdNot exceeding 1.15 x 10^6 J/m2
Moderate Fire Load threshold1.15 x 10^6 to 2.30 x 10^6 J/m2
Practical Notes
Ensure occupancy classification aligns with NBC Part 4, as IS 1641 definitions form its foundational basis.
Fire load calculations determine the required type of construction (Type 1 to 4) which dictates the choice of structural materials and cover.
Changes in a building's functional use post-construction often invalidate the initial fire grading, requiring immediate reassessment.