What is the minimum egress door width required by the IBC?

The IBC requires a minimum clear opening width of 32 inches for egress doors, measured between the face of the door and the stop with the door open 90 degrees (IBC 1010.1.1). A 36-inch nominal door is standard in commercial construction because it provides approximately 33-3/4 inches of clear width after accounting for hardware projection, satisfying both the 32-inch IBC minimum and accessibility requirements.

When does the IBC require doors to swing in the direction of egress?

Doors must swing in the direction of egress travel when the occupant load served by the door exceeds 50 (IBC 1010.1.2.1). This applies to each individual door along the egress path. High Hazard (Group H) occupancies require doors to swing in the direction of egress regardless of occupant load.

What fire rating does a door need in a 1-hour corridor wall?

A door in a 1-hour fire-rated corridor wall (fire partition) requires a minimum 20-minute fire protection rating (IBC Table 716.1). The door must be self-closing, self-latching, and the entire assembly (door, frame, hardware, and any glazing) must be listed and labeled for the 20-minute rating.

What is the difference between panic hardware and fire exit hardware?

Panic hardware is a door-latching device that releases when a horizontal force is applied to a push bar or crossbar. Fire exit hardware is panic hardware that has been tested and listed for use on fire-rated door assemblies. Standard panic hardware is not listed for fire-rated doors. When a fire-rated door requires panic hardware (such as an exit stairway door in an Assembly occupancy), fire exit hardware must be used.

Is glazing permitted in 90-minute fire-rated doors?

Yes, but glazing in 90-minute fire-rated doors is limited to a maximum of 100 square inches per lite, with a maximum dimension of 33 inches. The glazing must be fire-protection-rated and listed for the assembly. No glazing is permitted in 3-hour (180-minute) fire-rated doors.

Does NFPA 80 require annual fire door inspections?

Yes. NFPA 80 (2019 edition, Chapter 5) requires all fire door assemblies to be inspected annually by a knowledgeable individual. The inspection must verify that the door, frame, hardware, and glazing are intact, that clearances do not exceed maximums (1/8 inch at head and jambs, 3/4 inch at the bottom), that self-closing and self-latching devices function correctly, and that no field modifications have been made to the labeled assembly.

What are the maximum clearances for fire-rated door assemblies?

Per NFPA 80, the maximum clearance is 1/8 inch between the door and the frame at the head and jambs, and 1/8 inch at the meeting edges of paired doors. The maximum undercut (clearance at the bottom of the door) is 3/4 inch. Clearances exceeding these maximums compromise the fire rating of the assembly and must be corrected.

Can a fire-rated door be field-modified after installation?

NFPA 80 prohibits field modifications to labeled fire door assemblies unless the modification is specifically addressed by the product listing. Cutting, planing, adding non-listed hardware, or removing components from a labeled fire door voids the fire rating. Any necessary modifications must be performed in accordance with the manufacturer’s listing and approved by the AHJ.

Frequently Asked Questions

CDF Distributors fabricates hollow metal door and frame assemblies with fire protection ratings of 20 minutes, 45 minutes, 60 minutes, and 90 minutes. CDF rivets the appropriate fire label (FL20F through FL90F for frames, FL20D through FL90D for doors) onto every fire-rated assembly before shipping. Assemblies requiring a 3-hour (180-minute) rating use masonry frames and are available through CDF’s custom order process.

CDF’s ProBuilder tool at cdfdistributors.com structures each order as a complete assembly, ensuring the door, frame, and hardware are compatible and carry matching fire labels. For assistance selecting the correct assembly for your IBC-required fire rating, call (855) 769-9895 or email sales@cdfdoors.com.

Specifying IBC-Compliant Door Assemblies

N/R indicates no fire-resistance rating is required. Where no corridor rating is required, corridor doors are not required to be fire-rated. However, doors in the exit access path must still comply with egress hardware and dimensional requirements.

IBC Table 1020.1 specifies the required fire-resistance rating for corridor walls based on occupancy group and sprinkler status. The corridor wall rating directly determines the required door fire protection rating. The following table summarizes this relationship for the most common occupancy groups.

Corridor Wall Fire Ratings and Door Ratings by Occupancy

The IBC does not contain all fire door requirements within its own text. Instead, it adopts external standards by reference under IBC Chapter 35 (Referenced Standards). Two NFPA standards are central to commercial door compliance: NFPA 80 and NFPA 101. Understanding what the IBC delegates to these referenced standards is essential for complete code compliance.

NFPA 80: Standard for Fire Doors and Other Opening Protectives

NFPA 80 is the primary referenced standard for installation, inspection, testing, and maintenance of fire door assemblies. The IBC references NFPA 80 in Section 716.2.6.1 for the installation of fire door assemblies. Key NFPA 80 provisions include:

• Maximum clearances: 1/8 inch at the head and jambs for steel doors and frames, 1/8 inch at meeting edges of pairs. Undercut (bottom clearance) must not exceed 3/4 inch.

• Self-closing and self-latching: All fire doors must close and latch each time they are operated. Hold-open devices are permitted only if connected to the fire alarm system for automatic release.

• Field modifications: NFPA 80 prohibits field modifications to labeled fire door assemblies (cutting, planing, adding non-listed hardware) unless the modification is covered by the product listing.

• Annual inspection: NFPA 80 (2019 edition, Chapter 5) requires annual inspection of all fire door assemblies by a knowledgeable individual. Deficiencies must be corrected without delay.

• Gasketing and edge seals: Where required by the listing, smoke seals or gasketing must be installed and maintained.

NFPA 101: Life Safety Code

NFPA 101 is referenced by the IBC for certain egress and life safety provisions, particularly in jurisdictions that adopt both the IBC and NFPA 101 concurrently. While the IBC contains its own comprehensive egress chapter (Chapter 10), NFPA 101 provides additional or alternative requirements for:

• Existing building egress provisions (NFPA 101 includes requirements specific to existing buildings that may differ from new construction provisions in the IBC).

• Healthcare occupancy door requirements, including corridor door positive-latching requirements and cross-corridor smoke barrier door requirements in I-2 occupancies.

• Delayed egress locking provisions, which may differ in allowable delay times and required safeguards between the IBC and NFPA 101.

• Elevator lobby door requirements and pressurization alternatives.

In jurisdictions that adopt only the IBC, NFPA 80 is still adopted by reference for fire door installation and maintenance, but NFPA 101 applies only where specifically referenced by the IBC or by the AHJ. In jurisdictions that adopt both codes, the more restrictive requirement governs where conflicts exist.

How the IBC Adopts NFPA 80 and NFPA 101 by Reference

IBC Section 1010.1.9 establishes the hardware requirements for doors in the means of egress. The overriding principle is that egress doors must be openable from the egress side without a key, special knowledge, or special effort. The following requirements apply to all doors in the means of egress unless specifically excepted by the code.

Latching and Locking Hardware

• Doors must be openable from the egress side with a single operation (one motion to unlatch, one motion to open) without a key, special knowledge, or tight grasping, pinching, or twisting of the wrist (IBC 1010.1.9.2).

• Lever handles or push/pull hardware is required on accessible egress doors. Round knobs do not comply with accessibility requirements.

• Locks on egress doors must always be openable from the egress side without a key when the building is occupied.

• Delayed egress locks are permitted in specific occupancies (B, F, I, M, R, S) with sprinkler and fire alarm systems, subject to a maximum 15-second or 30-second delay (IBC 1010.1.9.8).

• Electromagnetic locks with sensor release are permitted where listed in the code, typically requiring a sensor that detects approaching occupants and releases the lock (IBC 1010.1.9.9).

Panic Hardware and Fire Exit Hardware

Panic hardware (push bars or crossbars) is required on egress doors serving Assembly (A) and Educational (E) occupancies when the occupant load served by the door exceeds 50 (IBC 1010.1.10). When panic hardware is installed on a fire-rated door, it must be listed as fire exit hardware. Standard panic hardware is not listed for use on fire-rated doors and must not be substituted for fire exit hardware.

• Panic hardware must release with a force of not more than 15 pounds applied in the direction of egress travel.

• Fire exit hardware must be self-latching and listed for the fire protection rating of the door assembly.

• Panic hardware must extend at least one-half the width of the door leaf (IBC 1010.1.10).

Door Closers

All fire-rated doors must be self-closing or automatic-closing (IBC 716.2.6.3). Door closers must be adjusted so that the door fully closes and latches each time it is released. The opening force for interior doors must not exceed 5 pounds (IBC 1010.1.3). The closing speed must allow the door to take at least 5 seconds to move from the full-open position (90 degrees) to 12 degrees from the latch (IBC 1010.1.3).

Hinges

Fire-rated door assemblies require steel hinges listed for the fire protection rating of the assembly. Spring hinges may serve as the self-closing device if listed for the application. The minimum number of hinges is based on door height: two hinges for doors up to 60 inches, three hinges for doors over 60 inches up to 90 inches, and one additional hinge for each additional 30 inches or fraction thereof.

Hardware Requirements for Means of Egress

Fire-resistance-rated glazing (as opposed to fire-protection-rated glazing) can provide larger glazed areas in some applications because it limits heat transmission in addition to blocking flames. When fire-resistance-rated glazing is used in a fire barrier, the glazing area may be limited only by the listing of the assembly rather than the prescriptive limits above. Verify glazing type and area limits with the specific product listing and the AHJ.

The IBC and NFPA 80 limit the maximum area of glazing (glass) in fire-rated door assemblies. Glazing must be fire-protection-rated or fire-resistance-rated depending on the application. Traditional wired glass and modern fire-rated ceramic glazing have different allowable areas and impact safety requirements. The following table summarizes the maximum glazing area permitted in fire-rated doors by rating level.

Maximum Glass Sizes in Fire-Rated Assemblies

Every component in a fire-rated door assembly, including hinges, closers, latching hardware, and glazing, must be listed and labeled for use in an assembly with the specified fire protection rating. Substituting unlisted components voids the assembly rating.

When the IBC requires a fire-rated door, the entire assembly must be listed and labeled, including the door, frame, glazing, and hardware. The fire protection rating of the door is always less than or equal to the fire-resistance rating of the wall, following the relationships established in IBC Table 716.1. The following table shows all five standard fire protection rating levels for doors and the corresponding frame and wall context.

Opening Protective Ratings: Door and Frame Requirements

IBC Table 716.1 (referenced as Table 716.5 in some editions) establishes the required fire protection rating for opening protectives based on the fire-resistance rating of the wall assembly. The table distinguishes between fire walls, fire barriers, fire partitions, smoke barriers, and corridor walls. The following table summarizes the most commonly referenced relationships between wall type, wall fire-resistance rating, and the required door fire protection rating.

Fire-Rated Opening Requirements by Wall Rating

The IBC organizes egress into three components: exit access, exit, and exit discharge. Each component has specific door requirements. Understanding where a door falls within the egress system determines the applicable fire rating, hardware, and locking restrictions.

Exit Access Doors

Exit access is the path from any occupied point to an exit. Doors within the exit access path include corridor doors, office suite entrance doors, and classroom doors. Corridor doors must meet the fire rating of the corridor wall per IBC Table 1020.1. In a non-sprinklered building, corridors serving occupant loads over 30 in Groups A, B, E, F, M, S, and U require a 1-hour fire-resistance rating with 20-minute fire-rated doors. Sprinklered buildings generally reduce or eliminate corridor fire-rating requirements.

Exit Doors

Exits include exit stairways, exit passageways, and horizontal exits. Doors in exit enclosures (stairwells) must have a fire-resistance rating of not less than 1 hour when the exit enclosure is required to have a 1-hour rating, or not less than 1-1/2 hours when the exit enclosure requires a 2-hour rating (IBC 1023.2). Exit doors must be self-closing, self-latching, and must not be equipped with locks that require a key or special knowledge to operate from the egress side.

Exit Discharge Doors

Exit discharge is the path from the exit to the public way. Doors at the exit discharge level must swing in the direction of egress travel and must be openable from the egress side without a key or special knowledge. Up to 50 percent of exits may discharge through the interior of the building (IBC 1028.1) provided the discharge path is protected by the same fire-resistance rating required for the exit enclosure and leads directly to the exterior.

Exit Access, Exit, and Exit Discharge Door Requirements

The IBC requires doors to swing in the direction of egress travel when the occupant load served by the door exceeds 50 (IBC 1010.1.2.1). This is one of the most frequently cited door provisions in plan review. The swing direction requirement applies to each individual door along the path of egress, not the total building occupant load.

Swing Direction Rules

• Doors must swing in the direction of egress travel when serving an occupant load of more than 50 (IBC 1010.1.2.1).

• Doors in Group H (High Hazard) occupancies must always swing in the direction of egress travel regardless of occupant load.

• Doors must not reduce the required corridor width by more than one-half when fully open (IBC 1010.1.2).

• Doors in the fully open position must not project more than 7 inches into the required corridor width (IBC 1010.1.2).

• Doors must not swing over landings, and the landing on the swing side must extend at least the width of the door leaf beyond the door opening.

Door Swing and Landing Clearances

IBC Section 1010.1.5 requires a floor or landing on each side of a door. The floor surface on both sides must be at the same elevation. An exception permits a threshold height of up to 1/2 inch at exterior doors and 3/4 inch at sliding doors. The landing depth on the swing side of the door must be at least the width of the door leaf. On the non-swing side, a 44-inch landing depth is required for doors serving more than 50 occupants.

Door Swing Requirements

IBC Section 1010.1.1 requires a minimum door height of 80 inches (6 feet 8 inches) for egress doors. This is the minimum clear height of the door opening. The 80-inch minimum applies to the nominal door height, not the frame height. The following height provisions apply.

• Minimum egress door height: 80 inches (IBC 1010.1.1).

• Doors not serving as required egress (e.g., closet doors, mechanical room access) are not required to meet the 80-inch minimum.

• Door frames are typically 84 inches (7 feet 0 inches) for standard commercial applications, providing clearance above the 80-inch door for hardware and weatherstripping.

• ADA/ICC A117.1 does not impose additional height requirements beyond the 80-inch IBC minimum but does require maneuvering clearances at the approach side of the door.

Door Height Requirements

Door Width Rules

• Minimum clear opening width: 32 inches, measured between the face of the door and the stop with the door open 90 degrees (IBC 1010.1.1).

• Maximum single leaf width: 48 inches (IBC 1010.1.1).

• Minimum door width for accessibility: 32 inches clear, though 36-inch nominal doors are standard to achieve this after accounting for hardware projection.

• Doors serving an occupant load of 10 or fewer in Group B or S occupancies may be 28 inches minimum clear width.

• Paired doors (double doors): At least one leaf must provide 32 inches of clear width independently without requiring the other leaf to open.

Example calculation: A business occupancy (Group B) with an occupant load of 200 in a sprinklered building requires a minimum egress width of 200 x 0.15 = 30 inches. Since the code minimum of 32 inches clear exceeds the calculated width, a single 36-inch door (providing approximately 33-3/4 inches clear) satisfies the requirement.

IBC Section 1005 establishes the minimum egress width based on occupant load. The code requires a minimum clear width per occupant that varies depending on whether the building is sprinklered and whether the component is a stairway or other egress element. For doors specifically, the minimum clear opening width is 32 inches, and the maximum leaf width is 48 inches. The following rules govern egress door width calculations.

Minimum Width Per Occupant

Egress Door Width Calculations

The IBC assigns occupancy classifications in Chapter 3, and each classification carries specific egress and fire protection requirements that affect door selection. The following table summarizes key door-related requirements by occupancy group. Occupant load thresholds determine when doors must swing in the direction of egress travel, and occupancy type determines the applicable corridor fire rating, which in turn dictates the door fire rating.

Door Requirements by Occupancy Group

This reference guide is compiled from the publicly available provisions of the International Building Code (IBC), primarily the 2021 edition, supplemented by referenced standards including NFPA 80 (Standard for Fire Doors and Other Opening Protectives) and NFPA 101 (Life Safety Code). It is intended as a practical reference for commercial door specification and does not replace the adopted code in any jurisdiction. Always verify requirements with the Authority Having Jurisdiction (AHJ) and the edition of the IBC adopted in your state or municipality.

About This Guide

The International Building Code (IBC) establishes minimum door requirements for commercial buildings based on occupancy type, fire separation rating, and means of egress capacity. IBC Chapter 10 governs egress door dimensions, swing direction, and hardware, while Chapter 7 specifies fire-rated opening protectives based on wall ratings. Together, these chapters define the door width, height, fire rating, glazing limits, and hardware required at every opening in a commercial building. This guide consolidates the IBC door provisions that architects, contractors, and building officials reference most frequently when specifying hollow metal doors and frames.

CDF Distributors supplies fire-rated and non-rated hollow metal door and frame assemblies that meet IBC requirements. You can configure compliant assemblies online using CDF’s ProBuilder tool at cdfdistributors.com. For assistance selecting the correct fire rating or hardware for your project, call (855) 769-9895 or email sales@cdfdoors.com.