IBC Chapter 10: Means of Egress
Exit requirements, occupant loads, and egress design criteria for safe evacuation
Last updated: November 5, 2025
Overview
IBC Chapter 10 provides comprehensive requirements for the design, construction, and arrangement of means of egress components required to provide safe evacuation from all structures and portions thereof. The 2024 edition includes updates for accessible means of egress, coordination with NFPA 101, and clarifications for exit discharge requirements.
The means of egress system consists of three parts: the exit access (path to an exit), the exit (protected path to exit discharge), and the exit discharge (path from exit to public way). Each component has specific requirements to ensure occupants can safely evacuate during emergencies.
Quick Reference
Fast answers to the most common egress questions:
How many exits do I need?
1-49
1 exit (with restrictions)
50-500
2 exits required
501-1,000
3 exits required
1,000+
4 exits required
Exit width requirements
Doors & corridors:
0.2" per person (0.15" if sprinklered)
Stairways:
0.3" per person (0.2" if sprinklered)
Minimum door:
32" clear (36" nominal)
Minimum corridor:
44" (36" with exceptions)
Common examples
100-person restaurant:
2 exits, 40" total door width
Small office (25 people):
May use 1 exit if under 75 ft travel
Apartment corridor:
44" wide (36" if < 50 occupants)
50+ assembly space:
Panic hardware required, doors swing out
Occupant Load Calculations
Occupant load determines the required number and capacity of exits:
| Function of Space | Floor Area per Occupant (sq ft) |
|---|---|
| Assembly Uses | |
| Concentrated (chairs only, auditoriums, churches) | 7 net |
| Standing space (concerts, bars, lobbies) | 5 net |
| Unconcentrated, tables & chairs (restaurants, libraries) | 15 net |
| Gaming floors (casinos) | 11 gross |
| Business Areas | |
| General business areas (offices, professional services) | 150 gross |
| Educational | |
| Classrooms | 20 net |
| Shops and other vocational areas | 50 net |
| Exercise Rooms | |
| With equipment | 50 gross |
| Without equipment | 15 gross |
| Industrial | |
| General industrial areas | 100 gross |
| Institutional | |
| Sleeping areas | 120 gross |
| Inpatient treatment areas (hospitals, nursing homes) | 240 gross |
| Outpatient areas (medical offices, clinics) | 100 gross |
| Daycare | 35 net |
| Mercantile | |
| Basement and grade floor areas | 30 gross |
| Areas on other floors | 60 gross |
| Storage, stock, shipping areas | 300 gross |
| Residential | |
| Hotels and apartments | 200 gross |
| Congregate living facilities (group homes) | 200 gross |
| Storage | |
| General storage areas | 500 gross |
| Mechanical equipment rooms | 300 gross |
| Parking | |
| Parking garages | 200 gross |
| Accessory | |
| Stages and platforms | 15 net |
| Accessory storage areas (100 sf or less) | 300 gross |
| Kitchens (commercial) | 200 gross |
Note: "Gross" area includes corridors, stairs, restrooms, and mechanical rooms. "Net" area excludes these spaces. Always verify requirements with the actual code adopted by your local jurisdiction. For spaces with fixed seating, see IBC Section 1004.6.
Calculation Method
- Divide floor area by occupant load factor from Table 1004.5
- For mixed occupancies, calculate each area separately
- Include all occupiable spaces in calculations
- Actual number of occupants if greater than calculated
- Posted occupant load required for assembly spaces over 50
Educational Tool: This calculator is provided for educational and informational purposes only. Occupant load calculations must be verified by a licensed design professional and approved by your local building official. Always consult with qualified professionals and local authorities having jurisdiction for official determinations.
Occupant Load Calculator
Number of Exits Required
| Occupant Load | Minimum Exits Required | Notes |
|---|---|---|
| 1-49 | 1 (with restrictions) | See single exit exceptions |
| 50-500 | 2 | Standard requirement |
| 501-1,000 | 3 | Additional capacity needed |
| Over 1,000 | 4 | Large assembly spaces |
Single Exit Exceptions (Table 1006.3.4)
- Business (B): 30 occupants max, 75 ft travel distance
- Mercantile (M): 30 occupants max, 75 ft travel distance
- Storage (S): 30 occupants max, 100 ft travel distance
- Residential (R-2): 4 dwelling units per floor, 2 stories max
- Buildings with automatic sprinkler systems may have increased limits
Exit Separation & Width
Exit Separation Requirements
- Two Exit Rule: Separated by 1/2 the maximum diagonal dimension of the area served
- Three or More Exits: Arranged a reasonable distance apart
- Sprinklered Buildings: Separation reduced to 1/3 the diagonal
- Measurement: In straight line between exit centerlines
- Interlocking Exits: Prohibited in high-rise buildings
Exit Width Calculations
- Stairways: 0.3 inches per occupant (0.2" if sprinklered)
- Other Egress: 0.2 inches per occupant (0.15" if sprinklered)
- Minimum Door Width: 32 inches clear (36 inches nominal)
- Minimum Corridor Width: 44 inches (36 inches with exceptions)
- Minimum Stair Width: 44 inches (36 inches for occupant load < 50)
Door & Hardware Requirements
Egress doors must meet specific requirements for swing direction, door hardware, and locking mechanisms to ensure safe evacuation during emergencies.
Door Swing Direction
- In Direction of Egress: Required for occupant loads over 50
- High Hazard: Always swing in direction of egress
- Exception: Individual dwelling units may swing either direction
- Encroachment: Cannot reduce required width by more than 7 inches when open 90°
Door Hardware & Locks
- Panic Hardware: Required for assembly and educational over 50 occupants
- Single Motion: One operation to release latch
- Operating Force: Maximum 15 pounds to release
- Height: 34-48 inches above floor
- Delayed Egress: 15-second maximum with sprinkler system
- Controlled Egress: Permitted in healthcare and detention
Special Locking Arrangements
- Electromagnetically locked egress doors (Section 1010.2.13)
- Sensor release of electrically locked doors (Section 1010.2.14)
- Stairway doors may be locked from stairway side (Section 1010.2.5)
Corridors & Stairways
Exit Access Corridors
- Fire-Resistance Rating: 1-hour for non-sprinklered, 0-hour for sprinklered (with exceptions)
- Width: 44 inches minimum (36 inches for occupant load < 50)
- Height: 7 feet 6 inches minimum
- Dead Ends: 20 feet maximum (50 feet if sprinklered)
- Projections: Maximum 1.5 inches decorative, 4 inches handrails
Interior Exit Stairways
- Enclosure: 2-hour for 4+ stories, 1-hour for less
- Width: 44 inches minimum (36 inches for occupant load < 50)
- Riser Height: 7 inches maximum, 4 inches minimum
- Tread Depth: 11 inches minimum
- Handrails: Both sides, 34-38 inches high
- Landings: Required every 12 feet vertical rise
Accessible Means of Egress
All accessible spaces must have accessible means of egress equal to the number of exits required:
Components of Accessible Routes
- Accessible Routes: Connect accessible spaces to exits
- Areas of Refuge: Required in non-sprinklered buildings
- Exterior Areas for Assisted Rescue: Alternative to areas of refuge
- Elevators: Permitted as part of accessible means of egress
- Platform Lifts: Permitted with restrictions
Area of Refuge Requirements
- Size: 30" x 48" clear space per wheelchair
- Separation: 1-hour fire-resistance rating minimum
- Communication: Two-way communication system to fire command
- Identification: Signs at doors to areas of refuge
- Instructions: Posted instructions for use
Code Edition Comparison
Key differences between IBC Chapter 10 editions (2015-2024):
| IBC Edition | Key Changes to Chapter 10 |
|---|---|
| 2015 IBC | Table 1004.1.2 for occupant load factors. Business occupancy at lower factor than current editions. |
| 2018 IBC | Renumbered Table 1004.1.2 to Table 1004.5. Increased business areas to 150 sf/person. Added concentrated business use (Section 1004.8) for call centers at 50 sf/person. |
| 2021 IBC | Reorganized Section 1010 (door requirements). Added power-operated door terminology. No changes to Table 1004.5 from 2018. |
| 2024 IBC | Added IT equipment facilities (300 gross sf/person) to Table 1004.5. Added definitions for flush bolts, dead bolts, manual bolts. Updated accessible means of egress provisions. |
Which edition applies to your project? Check with your local building department. Most jurisdictions adopt IBC editions 3-6 years after publication. Your project uses the code edition adopted by your jurisdiction at the time of permit application.
Frequently Asked Questions
How do I calculate occupant load for my building?
Divide the floor area by the occupant load factor from Table 1004.5. For example, a 3,000 sq ft restaurant with tables and chairs: 3,000 ÷ 15 = 200 occupants. For mixed uses, calculate each area separately and add them together.
How many exits do I need for my space?
It depends on occupant load: 1-49 people may use one exit (with restrictions), 50-500 need two exits, 501-1,000 need three exits, and over 1,000 need four exits. Single exit exceptions have specific travel distance and occupancy type limits.
What is the minimum corridor width for apartment buildings?
44 inches minimum for corridors serving an occupant load of 50 or more. 36 inches is permitted for corridors serving fewer than 50 occupants. Check if your corridor requires a fire-resistance rating based on the building's sprinkler status.
Do I need panic hardware on my doors?
Panic hardware is required for assembly and educational occupancies with 50 or more occupants. High-hazard occupancies require panic hardware regardless of occupant load. The hardware must release with 15 pounds of force or less and operate in a single motion.
What changed between 2021 and 2024 IBC Chapter 10?
The 2024 edition added IT equipment facilities to Table 1004.5, new definitions for bolt types (dead bolt, manual bolt, flush bolt), clarified door operations and hardware requirements, and updated accessible means of egress provisions. Table 1004.5 occupant load factors remained mostly unchanged except for the IT addition.
What's the difference between gross and net area for occupant load?
Gross area includes corridors, stairs, restrooms, and mechanical rooms. Net area excludes these non-occupiable spaces. Table 1004.5 specifies which to use for each occupancy type. For example, business offices use 150 gross sf/person, while classrooms use 20 net sf/person.
2024 IBC Updates
Key changes in the 2024 edition of Chapter 10:
- Exit Discharge: Clarified requirements for termination at public way
- Door Operations: Updated requirements for sensor-activated automatic doors
- Photoluminescent Markings: Expanded requirements for high-rise buildings
- Guards: Updated height requirements for certain occupancies
- Handrails: New provisions for alternating tread devices
- Emergency Escape: Clarified requirements for residential emergency escape openings
- Coordination: Better alignment with NFPA 101 Life Safety Code
Official Resources
Always consult the actual code adopted by your jurisdiction. These resources provide access to official IBC requirements:
ICC Digital Codes
Official online access to the complete International Building Code (requires free account for public view)
UpCodes
Free online tool for searching and referencing IBC and other building codes
I Dig Hardware
Building code insights from Lori Greene, code consultant and door hardware expert
Jurisdiction Verification: Building codes are adopted at the state or local level. Your project must comply with the specific edition and amendments adopted by your local building department. Contact your authority having jurisdiction (AHJ) to confirm which code edition applies.
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