General Definition

• Means of exiting refers to the continuous and unobstructed path of travel that allows occupants to safely evacuate a building in case of an emergency.
  • It includes all components of an egress system, such as exit access, exits, and exit discharge, ensuring compliance with fire safety and building codes.

• The above chart represents the importance levels of various exiting requirements for Group B occupancy.

• The following is a comparative table listing the mandatory means of existing requirements for Group B occupancy under the United States IBC (International Building Code) and their equivalent under the Japanese BSL (Building Standards Law).
  • By clicking on the blue underlined text, the reader will be directed to the specific means of exiting requirements for B occupancy under the USA (IBC) and Japanese (BSL:)

Means of Egress Aspect	IBC (International Building Code – USA)	BSL (Building Standards Law – Japan)
Occupancy Classification	Group B (Business – Office Buildings, Banks, Professional Services, Civic Administration)	Business Use Classification (事務所ビル, 銀行, 官公庁)
* Minimum Number of Exits	– 2 exits required for occupant loads > 49 (IBC 2018, Table 1006.3.2)	– At least 2 exits required for business use buildings exceeding a certain floor area (BSL Article 21)
* Exit Width Requirements	– Minimum 0.2 inches (5.08 mm) per occupant for stairs – Minimum 0.15 inches (3.81 mm) per occupant for other egress components (IBC 2018, 1005.3.1, 1005.3.2)	– Minimum 90 cm (35.4 inches) width per exit route (BSL Article 119) – 120 cm (47.2 inches) minimum for staircases in large office buildings
* Corridor Width	– Minimum 44 inches (1118 mm) (IBC 2018, 1020.2)	– Minimum 90 cm (35.4 inches) (BSL Article 119)
* Maximum Travel Distance to Exit	– 300 feet (91.44 m) (sprinklered) – 200 feet (60.96 m) (non-sprinklered) (IBC 2018, Table 1017.2)	– 40 m (131.2 feet) for non-sprinklered buildings – 60 m (196.8 feet) for sprinklered buildings (BSL Article 119)
* Common Path of Travel	– 100 feet (30.48 m) (sprinklered) – 75 feet (22.86 m) (non-sprinklered) (IBC 2018, Table 1006.2.1)	– 30 m (98.4 feet) (sprinklered) – 20 m (65.6 feet) (non-sprinklered) (BSL Article 119)
* Stairway Width	– Minimum 44 inches (1118 mm) for occupant load > 50 (IBC 2018, 1011.2)	– Minimum 120 cm (47.2 inches) for large office buildings (BSL Article 119)
* Minimum Ceiling Height	– Minimum 7 feet 6 inches (2286 mm) (IBC 2018, 1003.2)	– Minimum 2.1 m to 2.3 m (6 feet 10 inches to 7 feet 6 inches) depending on function (BSL Article 28)
* Exit Signage & Emergency Lighting	– Required in all business occupancies (IBC 2018, 1013, 1008.3)	– Required for office buildings (BSL Fire Code Enforcement Regulation Article 126)
* Fire Resistance for Exit Enclosures	– 1-hour fire rating for ≤ 3 stories – 2-hour fire rating for > 3 stories (IBC 2018, 1023.2)	– 1-hour fire rating for ≤ 3 stories – 2-hour fire rating for > 3 stories (BSL Article 35, Fire Service Law)
* Exiting Doors Requirements	– Minimum 32 inches (813 mm) clear width – Must swing in direction of egress travel for > 50 occupants (IBC 2018, 1010.1.1, 1010.1.2.1)	– Minimum 80 cm (31.5 inches) clear width – Must swing outward for large office buildings (BSL Article 119, Fire Safety Regulations)

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