Maximum travel distance to an exit refers to the farthest distance an occupant must travel to reach an exit in case of an emergency. IBC (USA) and BSL (Japan) both set maximum travel distances based on factors like fire protection systems (sprinklers), building occupancy, and fire resistance ratings.
IBC (International Building Code – USA)
The Maximum Travel Distance to Exit under the International Building Code (IBC) refers to the farthest distance an occupant must travel from any point in a building to reach an exit in case of an emergency.
BSL (Building Standards Law – Japan, 建築基準法)
The Maximum Travel Distance to Exit under Japan’s Building Standards Law (BSL, Article 119) defines the longest permitted distance an occupant can travel to reach an exit, considering fire safety risks.
IBC (USA) – Maximum Travel Distance to Exit
Under IBC 2018, Table 1017.2 the maximum allowable travel distance to an exit varies based on whether the building is sprinklered or non-sprinklered.
Key Requirements
Maximum Travel Distance in Sprinklered Buildings:
300 feet (91.44 m)
Applies to buildings protected by an automatic fire sprinkler system.
The increased distance is allowed because sprinklers provide additional fire suppression, reducing the urgency of evacuation.
Maximum Travel Distance in Non-Sprinklered Buildings:
200 feet (60.96 m)
Applies to buildings without fire sprinklers, requiring shorter exit routes to ensure occupants can evacuate quickly.
Exceptions & Adjustments for Specific Occupancies:
Industrial & Storage Buildings: Travel distances may be extended due to lower occupant density and fire separation features.
Assembly, Healthcare, and Residential Buildings: More restrictive travel distances apply in some cases.
Open-air structures: Can have longer travel distances if sufficient natural ventilation is present.
Fire Protection Features That Affect Travel Distance:
Fire-rated corridors and walls can allow for increased travel distances.
Smoke compartments in hospitals enable patients to shelter in place, reducing the need for immediate full evacuation.
BSL (Japan) – Maximum Travel Distance to Exit
Japan’s BSL (Building Standards Law, 建築基準法, Article 119) establishes maximum allowable travel distances based on fire safety measures and building type.
Key Requirements
Maximum Travel Distance in Non-Sprinklered Buildings:
40 meters (131.2 feet)
Applies to most non-sprinklered buildings, ensuring quick evacuation in case of fire.
Maximum Travel Distance in Sprinklered Buildings:
60 meters (196.8 feet)
Extended allowance for sprinklered buildings, but more restrictive than IBC.
Additional Restrictions Based on Building Type & Occupancy:
High-rise buildings (>31m or 10+ stories): May require shorter travel distances or additional stairwells.
Underground structures & tunnels: Stricter travel distance limits apply due to smoke accumulation risks.
Hospitals & Elderly Care Facilities: Require shorter travel distances due to occupant mobility concerns.
Fireproof Compartmentation & Exit Design:
Fireproof walls and compartmentation allow travel distances to be extended in some cases.
Multiple exits and refuge areas are required in public buildings to reduce overall travel distance.
Comparison Table: Maximum Travel Distance to Exit
Feature
IBC (USA) – Required
BSL (Japan) – Required
Maximum Travel Distance (Sprinklered Buildings)
300 feet (91.44 m)
60 meters (196.8 feet)
Maximum Travel Distance (Non-Sprinklered Buildings)
200 feet (60.96 m)
40 meters (131.2 feet)
High-Rise Buildings (10+ stories)
May require shorter distances
Often requires shorter travel distances
Hospitals & Care Facilities
Smoke compartments can allow longer distances
More restrictive travel distances due to mobility concerns
Travel Distance Compliance in a Mixed-Use Office Building – Honolulu vs. Tokyo
Project Overview
A 6-story mixed-use office building is planned for construction in:
Honolulu, USA (IBC jurisdiction)
Toyosu, Japan (BSL jurisdiction)
The building includes:
Office spaces on floors 2-6
Retail spaces on the ground floor
Two enclosed stairwells and one open-air emergency exit route
Honolulu (IBC) Compliance
Challenge:
The original design had a travel distance of 280 feet (85.3 m) from the farthest office space to an exit.
The building is fully sprinklered, so the 300-foot limit applies, but some corridors were at risk of exceeding this distance.
Solution:
Adjusted exit locations to keep all travel distances within 300 feet (91.44 m).
Added an additional egress corridor to reduce distance in the longest sections of the office floor plan.
Installed fire-rated walls to allow for minor extensions in travel distance as permitted by IBC.
Toyosu (BSL) Compliance
Challenge:
The original travel distance in the Tokyo office design was 62 meters (203.4 feet), exceeding the 60-meter limit for sprinklered buildings under BSL.
Solution:
Added an additional emergency stairwell near the farthest workspaces, reducing the maximum travel distance.
Repositioned fire-rated partitions to allow for controlled smoke compartmentation, meeting BSL fire safety standards.
Ensured all exit routes complied with Japan’s barrier-free accessibility requirements.
Final Universal Design Approach for Both Locations
To ensure compliance with both IBC (Honolulu) and BSL (Tokyo), the project adopted a universal design strategy:
Kept maximum travel distances within the stricter BSL limit (60m / 196.8 feet) to ensure compliance in both jurisdictions.
Reconfigured office layouts to optimize egress paths and reduce exit travel distances.
Used fire-rated partitions strategically to allow extended travel distances where permitted.
Maintained at least two fully enclosed stairwells for safe evacuation in both locations.
Key Takeaways
IBC allows for significantly longer travel distances (300 feet for sprinklered buildings) than BSL (60 meters / 196.8 feet).
BSL enforces stricter travel distances for non-sprinklered buildings (40 meters / 131.2 feet), while IBC allows up to 200 feet (60.96 meters).
IBC provides more flexibility through fire-rated compartmentation, while BSL relies more on shorter exit routes and additional stairwells.
A universal approach using shorter travel distances (≤60m) ensures compliance in both jurisdictions while improving overall fire safety.
Global Approach
To provide a universally compliant and safe travel distance to exits for Group B occupancy, harmonizing International Building Code (IBC, USA) and Building Standard Law (BSL, Japan), the following global recommendations are proposed:
Maximum Travel Distance
Sprinklered Buildings: Maximum distance of 60 meters (approximately 197 feet).
Non-Sprinklered Buildings: Maximum distance of 40 meters (approximately 131 feet).
These harmonized standards blend both IBC and BSL, ensuring safe and efficient evacuation globally.
High-Rise Buildings (10 or More Stories)
Shorter travel distances should be considered based on detailed risk assessments and occupant mobility considerations.
Reflects enhanced safety measures required by both IBC and BSL.
Hospitals & Care Facilities
Implement more restrictive travel distances to accommodate occupants with mobility impairments and complex evacuation scenarios.
Compliant with stricter standards found in both international codes.
Underground Buildings & Tunnels
Adopt stringent exit distance limits due to elevated risks of smoke accumulation and restricted evacuation pathways.
Consistent with rigorous safety requirements mandated by both jurisdictions.
Fire-Rated Walls & Smoke Compartments
Utilize fire-rated compartmentation and smoke compartments to permit increased travel distances, though stricter limits must be adhered to, ensuring occupant safety and international code compliance.
Following these global guidelines ensures robust safety, accessibility, and effective evacuation planning across diverse international projects.
TABLE 1017.2 EXIT ACCESS TRAVEL DISTANCE from the International Building Code (IBC):
OCCUPANCY
WITHOUT SPRINKLER SYSTEM (feet)
WITH SPRINKLER SYSTEM (feet)
A, E, F-1, M, R, S-1
200ᵉ
250ᵇ
I-1
Not Permitted
250ᵇ
B
200
300ᶜ
F-2, S-2, U
300
400ᶜ
H-1
Not Permitted
75ᵈ
H-2
Not Permitted
100ᵈ
H-3
Not Permitted
150ᵈ
H-4
Not Permitted
175ᵈ
H-5
Not Permitted
200ᶜ
I-2, I-3
Not Permitted
200ᶜ
I-4
150
200ᶜ
For SI: 1 foot = 304.8 mm.
a. See the following sections for modifications to exit access travel distance
requirements:
b. Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. See Section 903 for occupancies where automatic sprinkler systems are permitted in accordance with Section 903.3.1.2.
c. Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
d. Group H occupancies equipped throughout with an automatic sprinkler system in accordance with Section 903.2.5.1.
e. Group R-3 and R-4 buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.3. See Section 903.2.8 for occupancies where automatic sprinkler systems are permitted in accordance with Section 903.3.1.3
