ADOPTS WITH AMENDMENTS:

NFPA 101, 2018

Heads up: There are no amended sections in this chapter.

Annex A is not a part of the requirements of this NFPA document but is included for informational purposes only. This annex contains explanatory material, numbered to correspond with the applicable text paragraphs.

The following is a suggested procedure for determining the Code requirements for a building or structure:
  1. Determine the occupancy classification by referring to the occupancy definitions in Chapter 6 and the occupancy Chapters 12 through 42. (See 6.1.14 for buildings with more than one use.)
  2. Determine if the building or structure is new or existing. (See the definitions in Chapter 3.)
  3. Determine the occupant load. (See 7.3.1.)
  4. Determine the hazard of contents. (See Section 6.2.)
  5. Refer to the applicable occupancy chapter of the Code, Chapters 12 through 42. [See Chapters 1 through 4 and Chapters 6 through 11, as needed, for general information (such as definitions) or as directed by the occupancy chapter. ]
  6. Determine the occupancy subclassification or special use condition, if any, by referring to Chapters 16 and 17, day-care occupancies; Chapters 18 and 19, health care occupancies; Chapters 22 and 23, detention and correctional occupancies; Chapters 28 and 29, hotels and dormitories; Chapters 32 and 33, residential board and care occupancies; Chapters 36 and 37, mercantile occupancies; and Chapter 40, industrial occupancies, which contain subclassifications or special use definitions.
  7. Proceed through the applicable occupancy chapter to verify compliance with each referenced section, subsection, paragraph, subparagraph, and referenced codes, standards, and other documents.
  8. Where two or more requirements apply, refer to the occupancy chapter, which generally takes precedence over the base Chapters 1 through 4 and Chapters 6 through 11.
  9. Where two or more occupancy chapters apply, such as in a mixed occupancy (see 6.1.14), apply the most restrictive requirements.
Incidents involving hazardous materials are capable of posing significant life safety challenges in buildings. The Code recognizes this potential and includes technical requirements to address concerns related to hazardous material inventories and associated emergencies.
Life safety in buildings includes more than safety from fire. Although fire safety has been the long-standing focus of NFPA 101, its widely known title, Life Safety Code, and its technical requirements respond to a wider range of concerns, including, for example, crowd safety. Code requirements that contribute to the safe movement of people during fire emergencies might also assist in responding to many other hazards that require decisions about where people can be safely located.

A.1.1.9(1) This Code is intended to be adopted and used as part of a comprehensive program of building regulations that include building, mechanical, plumbing, electrical, fuel gas, fire prevention, and land use regulations.

The Code endeavors to avoid requirements that might involve unreasonable hardships or unnecessary inconvenience or interference with the normal use and occupancy of a building but provides for fire safety consistent with the public interest.

Protection of occupants is achieved by the combination of prevention, protection, egress, and other features, with due regard to the capabilities and reliability of the features involved. The level of life safety from fire is defined through requirements directed at the following:

  1. Prevention of ignition
  2. Detection of fire
  3. Control of fire development
  4. Confinement of the effects of fire
  5. Extinguishment of fire
  6. Provision of refuge or evacuation facilities, or both
  7. Staff reaction
  8. Provision of fire safety information to occupants
Various chapters contain specific provisions for existing buildings and structures that might differ from those for new construction.
Before a particular mathematical fire model or evaluation system is used, its purpose and limitations need to be known. The technical documentation should clearly identify any assumptions included in the evaluation. Also, it is the intent of the Committee on Safety to Life to recognize that future editions of this Code are a further refinement of this edition and earlier editions. The changes in future editions will reflect the continuing input of the fire protection/life safety community in its attempt to meet the purpose stated in this Code.
An equivalent method of protection provides an equal or greater level of safety. It is not a waiver or deletion of a Code requirement.

The prescriptive provisions of this Code provide specific requirements for broad classifications of buildings and structures. These requirements are stated in terms of fixed values, such as maximum travel distance, minimum fire resistance ratings, and minimum features of required systems, such as detection, alarm, suppression, and ventilation, and not in terms of overall building or system performance.

However, the equivalency clause in 1.4.3 permits the use of alternative systems, methods, or devices to meet the intent of the prescribed code provisions where approved as being equivalent. Through the rigor of a performance-based design, it can be demonstrated whether a building design is satisfactory and complies with the implicit or explicit intent of the applicable code requirement.

When employing the equivalency clause, it is important to clearly identify the prescriptive-based code provision being addressed (scope), to provide an interpretation of the intent of the provision (goals and objectives), to provide an alternative approach (proposed design), and to provide appropriate support for the suggested alternative (evaluation of proposed designs).

Performance resulting from proposed designs can be compared to the performance of the design features required by this Code. Using prescribed features as a baseline for comparison, it can then be demonstrated in the evaluation whether a proposed design offers the intended level of performance. A comparison of safety provided can be used as the basis for establishing equivalency.

A.2.1(1) For example, NFPA 10 is referenced in Chapter 2. This does not mean that all buildings must have portable fire extinguishers. Portable fire extinguishers are mandatory only to the extent called for elsewhere in the Code.

A.2.1(3) The Committee on Safety to Life recognizes that it is impractical to continually upgrade existing buildings or installations to comply with all the requirements of the referenced publications included in Chapter 2.

It is possible that governing authorities have adopted a code or standard other than one that is listed in Chapter 2. Where such is the case, and where a provision of a code or standard is referenced by this Code but the text of the requirement is not extracted into this Code, the code or standard adopted by the governing authority is permitted to be utilized where it is deemed by the authority having jurisdiction to adequately address the issue or condition of concern. Where the adopted code or standard does not address the issue, the requirement from the referenced code or standard should be applied by the authority having jurisdiction, unless the governing authority has established other procedures, policies, or guidelines. Where the text of a requirement is extracted from another NFPA code or standard and appears in this Code, it is the intent that the requirement be met as if it had originated in this Code, regardless of whether the governing authority has adopted the code or standard from which the text is extracted.
The National Fire Protection Association does not approve, inspect, or certify any installations, procedures, equipment, or materials; nor does it approve or evaluate testing laboratories. In determining the acceptability of installations, procedures, equipment, or materials, the authority having jurisdiction may base acceptance on compliance with NFPA or other appropriate standards. In the absence of such standards, said authority may require evidence of proper installation, procedure, or use. The authority having jurisdiction may also refer to the listings or labeling practices of an organization that is concerned with product evaluations and is thus in a position to determine compliance with appropriate standards for the current production of listed items.
The phrase "authority having jurisdiction," or its acronym AHJ, is used in NFPA documents in a broad manner, since jurisdictions and approval agencies vary, as do their responsibilities. Where public safety is primary, the authority having jurisdiction may be a federal, state, local, or other regional department or individual such as a fire chief; fire marshal; chief of a fire prevention bureau, labor department, or health department; building official; electrical inspector; or others having statutory authority. For insurance purposes, an insurance inspection department, rating bureau, or other insurance company representative may be the authority having jurisdiction. In many circumstances, the property owner or his or her designated agent assumes the role of the authority having jurisdiction; at government installations, the commanding officer or departmental official may be the authority having jurisdiction.
The decision to designate a standard as a "code" is based on such factors as the size and scope of the document, its intended use and form of adoption, and whether it contains substantial enforcement and administrative provisions.
The means for identifying listed equipment may vary for each organization concerned with product evaluation; some organizations do not recognize equipment as listed unless it is also labeled. The authority having jurisdiction should utilize the system employed by the listing organization to identify a listed product.
The active surface of the actuating bar needs to be visually and physically distinct from the rest of the device. The actuating bar is also called a cross bar or push pad.
Aisle accessway is the term used for the previously unnamed means of egress component leading to an aisle or other means of egress. For example, circulation space between parallel rows of seats having a width of 12 in. to 24 in. (305 mm to 610 mm) and a length not exceeding 100 ft (30 m) is an aisle accessway. Some of the circulation space between tables or seats in restaurants might be considered aisle accessway.

Depending on the width of aisle accessway, which is influenced by its length and expected utilization, the movement of a person through the aisle accessway might require others to change their individual speed of movement, alter their postures, move their chairs out of the way, or proceed ahead of the person.

Animal housing facilities, as used in this Code, are subject to local, state, or federal licensing or permitting requirements, and include, but are not limited to, the following:
  1. Barns and stables
  2. Kennels
  3. Racetrack stable/kennel areas including, those stable/kennel areas, barns, and associated buildings at state, county, and local fairgrounds
  4. Animal shelters
  5. Animal hospitals and veterinary facilities
  6. Zoos and special amusement parks
  7. Laboratories
  8. Agricultural facilities
  9. Mercantile or business occupancies with animals
Where the term floor area is used, it should be understood to be gross floor area, unless otherwise specified.
Hazardous areas include areas for the storage or use of combustibles or flammables; toxic, noxious, or corrosive materials; or heat-producing appliances.
Normally unoccupied building service support areas are often found in attics, crawl spaces, chases, and interstitial areas where the space is vacant or intended exclusively for routing ductwork, cables, conduits, piping, and similar services and is rarely accessed. In such spaces, it is often difficult or impossible to fully comply with the egress requirements of Chapter 7. Where portions of such spaces are routinely visited for storage, maintenance, testing, or inspection, that portion is excluded from this definition, but the remainder of the space might be considered a normally unoccupied building service equipment support area. Storage and fuel-fired equipment would not be expected to be permitted in these locations. Roofs are not considered to be normally unoccupied building service equipment support areas.
An area of refuge has a temporary use during egress. It generally serves as a staging area that provides relative safety to its occupants while potential emergencies are assessed, decisions are made, and mitigating activities are begun. Taking refuge within such an area is, thus, a stage of the total egress process, a stage between egress from the immediately threatened area and egress to a public way.

An area of refuge might be another building connected by a bridge or balcony, a compartment of a subdivided story, an elevator lobby, or an enlarged story-level exit stair landing. An area of refuge is accessible by means of horizontal travel or, as a minimum, via an accessible route meeting the requirements of ICC/ANSI A117.1, Accessible and Usable Buildings and Facilities.

This Code recognizes any floor in a building protected throughout by an approved, supervised automatic sprinkler system as an area of refuge. This recognition acknowledges the ability of a properly designed and functioning automatic sprinkler system to control a fire at its point of origin and to limit the production of toxic products to a level that is not life threatening.

The requirement for separated rooms or spaces can be met on an otherwise undivided floor by enclosing the elevator lobby with ordinary glass or other simple enclosing partitions that are smoke resisting.

For some occupancies, one accessible room or space is permitted.

As defined in NFPA 92 a large-volume space is an uncompartmented space, generally two or more stories high, within which smoke from a fire either in the space or in a communicating space can move and accumulate without restriction. Atria and covered mall concourses are examples of large-volume spaces.
The attic space might be used for storage. The concealed rafter space between the ceiling membrane and the roof sheathing that are attached to the rafters is not considered an attic.
A fire barrier, such as a wall or floor assembly, might be aligned vertically or horizontally. Although the continuity of a fire barrier will often limit the transfer of smoke, it should not be confused with either a smoke barrier or a smoke partition.
A smoke barrier might be vertically or horizontally aligned, such as a wall, floor, or ceiling assembly. A smoke barrier might or might not have a fire resistance rating. Application of smoke barrier criteria where required elsewhere in the Code should be in accordance with Section 8.3.
Finish ratings, as published in the UL Fire Resistance Directory, are one way of determining thermal barrier. A test method was developed in order to assess whether a material, product, or assembly constitutes a thermal barrier (see NFPA 275). It requires thermal barriers to meet both a test for fire resistance (temperature transmission test), which limits temperature rise on the unexposed side, and a test for reaction-to-fire (integrity fire test), intended to demonstrate that the material can prevent or delay ignition of the material on the unexposed side. The reaction to fire test is one of the following: NFPA 286, FM 4880, ANSI/UL 1040, or ANSI/UL 1715.
A birth center is a low-volume service for healthy, childbearing women, and their families, who are capable of ambulation in the event of fire or fire-threatening events. Birth center mothers and babies have minimal analgesia, receive no general or regional anesthesia, and are capable of ambulation, even in second-stage labor.
The term building is to be understood as if followed by the words or portions thereof. (See also Structure, A.3.3.282.)
The Code specifies that, wherever there are three or more living units in a building, the building is considered an apartment building and is required to comply with either Chapter 30 or Chapter 31, as appropriate. Townhouse units are considered to be apartment buildings if there are three or more units in the building. The type of wall required between units in order to consider them to be separate buildings is normally established by the authority having jurisdiction. If the units are separated by a wall of sufficient fire resistance and structural integrity to be considered as separate buildings, then the provisions of Chapter 24 apply to each townhouse. Condominium status is a form of ownership, not occupancy; for example, there are condominium warehouses, condominium apartments, and condominium offices.
With respect to judging whether a building should be considered existing, the deciding factor is not when the building was designed or when construction started but, rather, the date plans were approved for construction by the appropriate authority having jurisdiction.
Flexible plan buildings have movable corridor walls and movable partitions of full-height construction with doors leading from rooms to corridors. Open plan buildings have rooms and corridors delineated by tables, chairs, desks, bookcases, counters, low-height partitions, or similar furnishings. It is the intent that low-height partitions not exceed 60 in. (1525 mm).
It is the intent of this definition that, in determining the level from which the highest occupiable floor is to be measured, the enforcing agency should exercise reasonable judgment, including consideration of overall accessibility to the building by fire department personnel and vehicular equipment. Where a building is situated on a sloping terrain and there is building access on more than one level, the enforcing agency might select the level that provides the most logical and adequate fire department access.
Designation for a historic building might be in an official national, regional, or local historic register, listing, or inventory.
Special amusement buildings include amusements such as a haunted house, a roller coaster-type ride within a building, a multilevel play structure within a building, a submarine ride, and similar amusements where the occupants are not in the open air.
Where no building code has been adopted, NFPA 5000 should be used where the building code is referenced in this Code.
Cellular or foamed plastic might contain foamed and unfoamed polymeric or monomeric precursors (prepolymer, if used), plasticizers, fillers, extenders, catalysts, blowing agents, colorants, stabilizers, lubricants, surfactants, pigments, reaction control agents, processing aids, and flame retardants.
Common path of travel is measured in the same manner as travel distance but terminates at that point where two separate and distinct routes become available. Paths that merge are common paths of travel.
Additional fire compartment information is contained in 8.2.2.

In the provisions for fire compartments utilizing the outside walls of a building, it is not intended that the outside wall be specifically fire resistance rated, unless required by other standards. Likewise, it is not intended that outside windows or doors be protected, unless specifically required for exposure protection by another section of this Code or by other standards.

Where smoke compartments using the outside walls or the roof of a building are provided, it is not intended that outside walls or roofs, or any openings therein, be capable of resisting the passage of smoke. Application of smoke compartment criteria where required elsewhere in the Code should be in accordance with Section 8.5.
Critical radiant flux is the property determined by the test procedure of NFPA 253 or by ASTM E648, Standard Test Method for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source. The unit of measurement of critical radiant flux is watts per square centimeter (W/cm2).
An emergency stair travel device should be designed, constructed, and operated in accordance with ANSI/RESNA ED-1, Emergency Stair Travel Devices Used by Individuals with Disabilities. The device typically requires the assistance of a trained operator.
Rooms within dormitories intended for the use of individuals for combined living and sleeping purposes are guest rooms or guest suites. Examples of dormitories are college dormitories, fraternity and sorority houses, and military barracks.
It is not the intent of the Code that the list of spaces in the definition of the term dwelling unit in 3.3.67 is to be all inclusive. It is the intent of the Code that the list of spaces is a minimal set of criteria that must be provided to be considered a dwelling unit, and, therefore, the dwelling unit can contain other spaces that are typical to a single-family dwelling.
The application statement of 24.1.1.1 limits each dwelling unit to being "occupied by members of a single family with not more than three outsiders." The Code does not define the term family. The definition of family is subject to federal, state, and local regulations and might not be restricted to a person or a couple (two people) and their children. The following examples aid in differentiating between a single-family dwelling and a lodging or rooming house:
  1. An individual or a couple (two people) who rent a house from a landlord and then sublease space for up to three individuals should be considered a family renting to a maximum of three outsiders, and the house should be regulated as a single-family dwelling in accordance with Chapter 24.
  2. A house rented from a landlord by an individual or a couple (two people) in which space is subleased to 4 or more individuals, but not more than 16, should be considered and regulated as a lodging or rooming house in accordance with Chapter 26.
  3. A residential building that is occupied by 4 or more individuals, but not more than 16, each renting from a landlord, without separate cooking facilities, should be considered and regulated as a lodging or rooming house in accordance with Chapter 26.
This light source is typically contained inside the device.
The evacuation capability of the residents and staff is a function of both the ability of the residents to evacuate and the assistance provided by the staff. It is intended that the evacuation capability be determined by the procedure acceptable to the authority having jurisdiction. It is also intended that the timing of drills, the rating of residents, and similar actions related to determining the evacuation capability be performed by persons approved by or acceptable to the authority having jurisdiction. The evacuation capability can be determined by the use of the definitions in 3.3.81, the application of NFPA 101A Chapter 6, or a program of drills (timed).

Evacuation does not include the relocation of occupants within a building.

Where drills are used in determining evacuation capability, it is suggested that the facility conduct and record fire drills six times per year on a bimonthly basis, with a minimum of two drills conducted during the night when residents are sleeping, and that the facility conduct the drills in consultation with the authority having jurisdiction. Records should indicate the time taken to reach a point of safety, date and time of day, location of simulated fire origin, escape paths used, and comments relating to residents who resisted or failed to participate in the drills.

Translation of drill times to evacuation capability is determined as follows:

  1. 3 minutes or less — prompt
  2. Over 3 minutes, but not in excess of 13 minutes — slow
  3. More than 13 minutes — impractical

Evacuation capability, in all cases, is based on the time of day or night when evacuation of the facility would be most difficult, such as when residents are sleeping or fewer staff are present.

Evacuation capability determination is considered slow if the following conditions are met:

  1. All residents are able to travel to centralized dining facilities without continuous staff assistance.
  2. There is continuous staffing whenever there are residents in the facility.
Exits include exterior exit doors, exit passageways, horizontal exits, exit stairs, and exit ramps. In the case of a stairway, the exit includes the stair enclosure, the door to the stair enclosure, the stairs and landings inside the enclosure, the door from the stair enclosure to the outside or to the level of exit discharge, and any exit passageway and its associated doors, if such are provided, so as to discharge the stair directly to the outside. In the case of a door leading directly from the street floor to the street or open air, the exit comprises only the door. (See also 7.2.2.6.3.1 and A.7.2.2.6.3.1.)

Doors of small individual rooms, as in hotels, while constituting exit access from the room, are not referred to as exits, except where they lead directly to the outside of the building from the street floor.

Horizontal exits should not be confused with egress through doors in smoke barriers. Doors in smoke barriers are designed only for temporary protection against smoke, whereas horizontal exits provide protection against serious fire for a relatively long period of time in addition to providing immediate protection from smoke. (See 7.2.4.)
Low occupancy, ancillary spaces with exit doors discharging directly to the outside, such as mechanical equipment rooms or storage areas, that are located on levels other than main occupiable floors should not be considered in the determination of level of exit discharge.
An exposure fire usually refers to a fire that starts outside a building, such as a wildlands fire or vehicle fire, and that, consequently, exposes the building to a fire.
Limited care facilities and residential board and care occupancies both provide care to people with physical and mental limitations. However, the goals and programs of the two types of occupancies differ greatly. The requirements in this Code for limited care facilities are based on the assumption that these are medical facilities, that they provide medical care and treatment, and that the patients are not trained to respond to the fire alarm; that is, the patients do not participate in fire drills but, rather, await rescue. (See Section 18.7.)

The requirements for residential board and care occupancies are based on the assumption that the residents are provided with personal care and activities that foster continued independence, that the residents are encouraged and taught to overcome their limitations, and that most residents, including all residents in prompt and slow homes, are trained to respond to fire drills to the extent they are able. Residents are required to participate in fire drills. (See Section 32.7.)

Persons with Alzheimer's and related illnesses might be located in a nursing home, limited care facility, or board and care facility. For such persons, it is the level of care provided, not the medical diagnosis, that matters for the purposes of determining whether the facility should meet the requirements for limited care. Where personal care is provided but medical or custodial care is not, the limited care definition does not typically apply. It is the intent of this definition that it not apply to persons not receiving medical or custodial care, provided they are able to assist in their own evacuation, regardless of their medical diagnosis.

Interior finish is not intended to apply to surfaces within spaces such as those that are concealed or inaccessible. Furnishings that, in some cases, might be secured in place for functional reasons should not be considered as interior finish.
Interior floor finish includes coverings applied over a normal finished floor or stair treads and risers.
Such partitions are intended to include washroom water closet partitions.
Where no fire code has been adopted, NFPA 1 should be used where the fire code is referenced in this Code.
Due to the complex nature of the principles involved, models are often packaged as computer software. Any relevant input data, assumptions, and limitations needed to properly implement the model will be attached to the fire models.
A fire scenario defines the conditions under which a proposed design is expected to meet the fire safety goals. Factors typically include fuel characteristics, ignition sources, ventilation, building characteristics, and occupant locations and characteristics. The term fire scenario includes more than the characteristics of the fire itself but excludes design specifications and any characteristics that do not vary from one fire to another; the latter are called assumptions. The term fire scenario is used here to mean only those specifications required to calculate the fire's development and effects, but, in other contexts, the term might be used to mean both the initial specifications and the subsequent development and effects (i.e., a complete description of fire from conditions prior to ignition to conditions following extinguishment).
See 4.6.17 for provisions for establishing the grade plane. Vertical measurements might be used in determining the number of stories or building height.
Where the term grandstand is preceded by an adjective denoting a material, it means a grandstand the essential members of which, exclusive of seating, are of the material designated.
The heat release rate of a fuel is related to its chemistry, physical form, and availability of oxidant and is ordinarily expressed as British thermal units per second (Btu/s) or kilowatts (kW).

Chapters 40 and 42 include detailed provisions on high hazard industrial and storage occupancies.

A day-care home is generally located within a dwelling unit.
So-called apartment hotels should be classified as hotels, because they are potentially subject to the same transient occupancy as hotels. Transients are those who occupy accommodations for less than 30 days.
The light source is typically a dedicated incandescent or fluorescent source.
The light source is typically incandescent, fluorescent, electroluminescent, photo-luminescent, or self-luminous or is a light-emitting diode(s).
An open mall concourse is permitted to serve as the public way provided the open mall concourse meets the definition of public way in accordance with this Code.

It is intended that the open mall concourse be designed, constructed, and arranged to permit the natural venting of smoke and other products of combustion to the outside air through openings in the walls, roof, or combination thereof of the mall concourse.

The solid area of the mall concourse walls and the horizontal projection of the solid area of any roof structures, including shade structures, awnings, and canopies, that cover the mall concourse should be summed to determine the aggregate area of solid construction associated with the mall concourse. A mall concourse can be considered an open mall concourse where at least 50 percent of the aggregate area of solid construction is open to the atmosphere. Open areas can include entrances to the mall concourse (e.g., barred gates that allow air to pass through versus an entrance storefront), clearstory spaces between the mall building (structure that houses tenants) and the roof above, and openings in the roof assembly. For the openings to be effective, they must also be distributed uniformly over the length of the mall concourse. Caution must be exercised in the design and construction so as to not create areas of possible congestion for smoke and hot gases to accumulate, such as a pitched (steep slope) roof assembly within the mall concourse

Roof assemblies are permitted to have holes or open areas that represent openings to the outside. The roof assembly is also permitted to consist of a structure or assembly that allows the venting of the mall concourse. Examples of these vented roof structures include a roof trellis or an exposed roof structural frame only with no roofing materials. Structures that would permit the omission of automatic sprinkler protection, in accordance with NFPA 13, could be included to serve as open space for the purposes of the calculation of areas open to the outside air. Caution should be taken not to allow vegetation to grow into and around these structures that could reduce or impede the venting capabilities

A means of egress comprises the vertical and horizontal travel and includes intervening room spaces, doorways, hallways, corridors, passageways, balconies, ramps, stairs, elevators, enclosures, lobbies, escalators, horizontal exits, courts, and yards.
For the purpose of fire protection features, a membrane can consist of materials such as gypsum board, plywood, glass, or fabric. For the purpose of membrane structures, a membrane consists of thin, flexible, water-impervious material capable of being supported by an air pressure of 11/2 in. (38 mm) water column.
Modification does not include repair or replacement of interior finishes.
Objectives define a series of actions necessary to make the achievement of a goal more likely. Objectives are stated in more specific terms than goals and are measured on a more quantitative, rather than qualitative, basis.
It is not the intent that occupants be considered to be incapable of self-preservation just because they are in a wheelchair or use assistive walking devices, such as a cane, a walker, or crutches. Rather, it is the intent to address treatment centers that receive patients who have been rendered incapable of self-preservation such as being rendered unconscious as a result of an accident or being unable to move due to sudden illness.

It is not the intent that the term anesthesia be limited to general anesthesia.

Assembly occupancies might include the following:
  1. Armories
  2. Assembly halls
  3. Auditoriums
  4. Bowling lanes
  5. Club rooms
  6. College and university classrooms, 50 persons and over
  7. Conference rooms
  8. Courtrooms
  9. Dance halls
  10. Drinking establishments
  11. Exhibition halls
  12. Gymnasiums
  13. Libraries
  14. Mortuary chapels
  15. Motion picture theaters
  16. Museums
  17. Passenger stations and terminals of air, surface, underground, and marine public transportation facilities
  18. Places of religious worship
  19. Pool rooms
  20. Recreation piers
  21. Restaurants
  22. Skating rinks
  23. Special amusement buildings, regardless of occupant load
  24. Theaters

Assembly occupancies are characterized by the presence or potential presence of crowds with attendant panic hazard in case of fire or other emergency. They are generally open or occasionally open to the public, and the occupants, who are present voluntarily, are not ordinarily subject to discipline or control. Such buildings are ordinarily occupied by able-bodied persons and are not used for sleeping purposes. Special conference rooms, snack areas, and other areas incidental to, and under the control of, the management of other occupancies, such as offices, fall under the 50-person limitation.

Restaurants and drinking establishments with an occupant load of fewer than 50 persons should be classified as mercantile occupancies.

For special amusement buildings, see 12.4.8 and 13.4.8.

Business occupancies include the following:
  1. Airport traffic control towers (ATCTs)
  2. City halls
  3. College and university instructional buildings, classrooms under 50 persons, and instructional laboratories
  4. Courthouses
  5. Dentists' offices
  6. Doctors' offices
  7. General offices
  8. Outpatient clinics (ambulatory)
  9. Town halls

Doctors' and dentists' offices are included, unless of such character as to be classified as ambulatory health care occupancies. (See 3.3.196.1)

Birth centers should be classified as business occupancies if they are occupied by fewer than four patients, not including infants, at any one time; do not provide sleeping facilities for four or more occupants; and do not provide treatment procedures that render four or more patients, not including infants, incapable of self-preservation at any one time. For birth centers occupied by patients not meeting these parameters, see Chapter 18 or Chapter 19, as appropriate.

Service facilities common to city office buildings, such as newsstands, lunch counters serving fewer than 50 persons, barber shops, and beauty parlors are included in the business occupancy group.

City halls, town halls, and courthouses are included in this occupancy group, insofar as their principal function is the transaction of public business and the keeping of books and records. Insofar as they are used for assembly purposes, they are classified as assembly occupancies.

Day-care occupancies include the following:
  1. Adult day-care occupancies, except where part of a health care occupancy
  2. Child day-care occupancies
  3. Day-care homes
  4. Kindergarten classes that are incidental to a child day-care occupancy
  5. Nursery schools

In areas where public schools offer only half-day kindergarten programs, many child day-care occupancies offer state-approved kindergarten classes for children who need full-day care. Because these classes are normally incidental to the day-care occupancy, the requirements of the day-care occupancy should be followed.

Detention and correctional occupancies include the following:
  1. Adult and juvenile substance abuse centers
  2. Adult and juvenile work camps
  3. Adult community residential centers
  4. Adult correctional institutions
  5. Adult local detention facilities
  6. Juvenile community residential centers
  7. Juvenile detention facilities
  8. Juvenile training schools

See A.22.1.1.1.6 and A.23.1.1.1.6.

Educational occupancies include the following:
  1. Academies
  2. Kindergartens
  3. Schools

An educational occupancy is distinguished from an assembly occupancy in that the same occupants are regularly present.

Health care occupancies include the following:
  1. Hospitals
  2. Limited care facilities
  3. Nursing homes

Occupants of health care occupancies typically have physical or mental illness, disease, or infirmity. They also include infants, convalescents, or infirm aged persons. It is not the intent to consider occupants incapable of self-preservation because they are in a wheelchair or use assistive walking devices, such as a cane, a walker, or crutches.

Industrial occupancies include the following:
  1. Drycleaning plants
  2. Factories of all kinds
  3. Food processing plants
  4. Gas plants
  5. Hangars (for servicing/maintenance)
  6. Laundries
  7. Power plants
  8. Pumping stations
  9. Refineries
  10. Sawmills
  11. Telephone exchanges

In evaluating the appropriate classification of laboratories, the authority having jurisdiction should treat each case individually, based on the extent and nature of the associated hazards. Some laboratories are classified as occupancies other than industrial; for example, a physical therapy laboratory or a computer laboratory.

General industrial occupancies include multistory buildings where floors are occupied by different tenants or buildings suitable for such occupancy and, therefore, are subject to possible use for types of industrial processes with a high density of employee population.
A high hazard industrial occupancy includes occupancies where gasoline and other flammable liquids are handled, used, or stored under such conditions that involve possible release of flammable vapors; where grain dust, wood flour or plastic dust, aluminum or magnesium dust, or other explosive dusts are produced; where hazardous chemicals or explosives are manufactured, stored, or handled; where materials are processed or handled under conditions that might produce flammable flyings; and where other situations of similar hazard exist. Chapters 40 and 42 include detailed provisions on high hazard industrial and storage occupancies.
Mercantile occupancies include the following:
  1. Auction rooms
  2. Department stores
  3. Drugstores
  4. Restaurants with fewer than 50 persons
  5. Shopping centers
  6. Supermarkets

Office, storage, and service facilities incidental to the sale of merchandise and located in the same building should be considered part of the mercantile occupancy classification.

The following are examples of facilities that are classified as residential board and care occupancies:
  1. Group housing arrangement for physically or mentally handicapped persons who normally attend school in the community, attend worship in the community, or otherwise use community facilities
  2. Group housing arrangement for physically or mentally handicapped persons who are undergoing training in preparation for independent living, for paid employment, or for other normal community activities
  3. Group housing arrangement for the elderly that provides personal care services but that does not provide nursing care
  4. Facilities for social rehabilitation, alcoholism, drug abuse, or mental health problems that contain a group housing arrangement and that provide personal care services but do not provide acute care
  5. Assisted living facilities
  6. Other group housing arrangements that provide personal care services but not nursing care
Residential occupancies are treated as separate occupancies in this Code as follows:
  1. One- and two-family dwellings (Chapter 24)
  2. Lodging or rooming houses (Chapter 26)
  3. Hotels, motels, and dormitories (Chapters 28 and 29)
  4. Apartment buildings (Chapters 30 and 31)
Storage occupancies include the following:
  1. Barns
  2. Bulk oil storage
  3. Cold storage
  4. Freight terminals
  5. Grain elevators
  6. Hangars (for storage only)
  7. Parking structures
  8. Truck and marine terminals
  9. Warehouses

Storage occupancies are characterized by the presence of relatively small numbers of persons in proportion to the area.

Performance criteria are stated in engineering terms. Engineering terms include temperatures, radiant heat flux, and levels of exposure to fire products. Performance criteria provide threshold values used to evaluate a proposed design.
Personal care involves responsibility for the safety of the resident while inside the building. Personal care might include daily awareness by management of the resident's functioning and whereabouts, making and reminding a resident of appointments, the ability and readiness for intervention in the event of a resident experiencing a crisis, supervision in the areas of nutrition and medication, and actual provision of transient medical care.
The released light is normally visible for a limited time if the ambient light sources are removed or partially obscured.
Platforms also include the head tables for special guests; the raised area for lecturers and speakers; boxing and wrestling rings; theater-in-the-round; and for similar purposes wherein there are no overhead drops, pieces of scenery, or stage effects other than lighting and a screening valance.

A platform is not intended to be prohibited from using a curtain as a valance to screen or hide the electric conduit, lighting track, or similar fixtures, nor is a platform prohibited from using curtains that are used to obscure the back wall of the stage; from using a curtain between the auditorium and the stage (grand or house curtain); from using a maximum of four leg drops; or from using a valance to screen light panels, plumbing, and similar equipment from view.

A pedestrian action might include pressing a push plate or waving a hand in front of a sensor.
A provision used to prevent entrapment might include sensors.
The design team might develop a number of trial designs that will be evaluated to determine whether they meet the performance criteria. One of the trial designs will be selected from those that meet the performance criteria for submission to the authority having jurisdiction as the proposed design.

The proposed design is not necessarily limited to fire protection systems and building features. It also includes any component of the proposed design that is installed, established, or maintained for the purpose of life safety, without which the proposed design could fail to achieve specified performance criteria. Therefore, the proposed design often includes emergency procedures and organizational structures that are needed to meet the performance criteria specified for the proposed design.

The intent of the definition of public way is to establish an end point at which the means of egress terminates, is not under the jurisdiction of the Code, and to which the Code's requirements do not apply. As such, the Code intends a situation where occupants egressing from a building ultimately reach a point where they can move away from the building unimpeded and no longer need the protections of the Code.
The acceptance criteria for determining fire protection ratings for fire door assemblies are described in NFPA 252 and those for fire window assemblies are described in NFPA 257.
It is not the intent that a corridor, an aisle, or a circulation space within a suite be considered as a corridor that is shared by more than one occupant space. The suite should be considered as only one occupant space. The following situations should be considered to involve more than one occupant space:
  1. Work affecting a corridor that is common to multiple guest rooms on a floor of a hotel occupancy
  2. Work affecting a corridor that is common to multiple living units on a floor of an apartment building occupancy
  3. Work affecting a corridor that is common to multiple tenants on a floor of a business occupancy
Festival seating describes situations in assembly occupancies where live entertainment events are held that are expected to result in overcrowding and high audience density that can compromise public safety. It is not the intent to apply the term festival seating to exhibitions; sports events; conventions; and bona fide political, religious, and educational events. Assembly occupancies with 15 ft2 (1.4 m2) or more per person should not be considered festival seating.
An example of a self-contained power source is tritium gas. Batteries do not qualify as a self-contained power source. The light source is typically contained inside the device.
Examples of clients who are incapable of self-preservation include infants, clients who are unable to use stairs because of confinement to a wheelchair or other physical disability, and clients who cannot follow directions or a group to the outside of a facility due to mental or behavioral disorders. It is the intent of this Code to classify children under the age of 30 months as incapable of self-preservation. Examples of direct intervention by staff members include carrying a client, pushing a client outside in a wheelchair, and guiding a client by direct hand-holding or continued bodily contact. If clients cannot exit the building by themselves with minimal intervention from staff members, such as verbal orders, classification as incapable of self-preservation should be considered.
Situation awareness (also called situational awareness), described in a simpler fashion, is being aware of what is happening around you and understanding what that information means to you now and in the future. This definition, and the more formal definition, come from the extensive work of human factors (ergonomics) experts in situation awareness, most notably Mica R. Endsley (Endsley, Bolte and Jones, Designing for Situation Awareness: An approach to user-centered design, CRC Press, Taylor and Francis, Boca Raton, FL, 2003). Within the Code, and the standards it references, are long-standing requirements for systems and facilities that enhance situation awareness. Included are fire/smoke detection, alarm, and communication systems plus the system status panels in emergency command centers; supervisory systems for various especially critical components (e.g., certain valves) of fire protection systems; waterflow indicators; certain signs; and the availability of trained staff, notably in health care occupancies. Serious failures of situation awareness have been identified as central to unfortunate outcomes in various emergencies; for example, typical responses of people to developing fires also exhibit situation awareness problems as incorrect assumptions are made about the rapidity of fire growth or the effect of opening a door. Good situation awareness is critical to decision making, which, in turn, is critical to performance during an emergency.
For further guidance, see the following publications:
  1. ASHRAE Handbook and Product DirectoryFundamentals
  2. Principles of Smoke Management, by Klote and Milke
  3. NFPA 105, Standard for Smoke Door Assemblies and Other Opening Protectives
Design specifications include both hardware and human factors, such as the conditions produced by maintenance and training. For purposes of performance-based design, the design specifications of interest are those that affect the ability of the building to meet the stated goals and objectives.
Stories below the level of exit discharge are not counted as stories for determining the stories in height of a building.
Stories used exclusively for mechanical equipment rooms, elevator penthouses, and similar spaces are not occupiable stories.
Where, due to differences in street levels, two or more stories are accessible from the street, each is a street floor. Where there is no floor level within the specified limits for a street floor above or below the finished ground level, the building has no street floor.
The term structure is to be understood as if followed by the words or portion thereof. (See also Building, A.3.3.37.)
A cable-restrained air-supported structure is one in which the uplift is resisted by cables or webbing that is anchored by various methods to the membrane or that might be an integral part of the membrane. An air-supported structure is not a tensioned-membrane structure.
A mall structure might enclose one or more uses, such as retail and wholesale stores, drinking and dining establishments, entertainment and amusement facilities, transportation facilities, offices, and other similar uses.
Open structures are often found in oil refining, chemical processing, or power plants. Roofs or canopies without enclosing walls are not considered an enclosure.
A parking structure is permitted to be enclosed or open, use ramps, and use mechanical control push-button-type elevators to transfer vehicles from one floor to another. Motor vehicles are permitted to be parked by the driver or an attendant or are permitted to be parked mechanically by automated facilities. Where automated-type parking is provided, the operator of those facilities is permitted either to remain at the entry level or to travel to another level. Motor fuel is permitted to be dispensed, and motor vehicles are permitted to be serviced in a parking structure in accordance with NFPA 30A. [88A, 2015]
In determining openings in exterior walls, doors or access panels are permitted to be included. Windows are also permitted to be included, provided that they are openable or provide a breakable glazed area.

Floor levels that are located not more than 30 ft (9.1 m) below the lowest level with an exit discharge can be considered a basement. See 3.3.33.

A tent might also include a temporary tensioned-membrane structure.
Vertical openings might include items such as stairways; hoistways for elevators, dumbwaiters, and inclined and vertical conveyors; shaftways used for light, ventilation, or building services; or expansion joints and seismic joints used to allow structural movements.
Wall or ceiling coverings with ink or top coat layers added as part of the manufacturing process are included in this definition. The term "polymeric" is intended to include "vinyl."
The goals in Section 4.1 reflect the scope of this Code (see Section 1.1). Other fire safety goals that are outside the scope of this Code might also need to be considered, such as property protection and continuity of operations. Compliance with this Code can assist in meeting goals outside the scope of the Code.
Reasonable safety risk is further defined by subsequent language in this Code.

A.4.1.1(1) The phrase "intimate with the initial fire development" refers to the person(s) at the ignition source or first materials burning, not to all persons within the same room or area.

"Comparable emergencies" refers to incidents where the hazard involves thermal attributes similar to fires or airborne contaminants similar to smoke, such that features mandated by this Code can be expected to mitigate the hazard. Examples of such incidents might be explosions and hazardous material releases. The Code recognizes that features mandated by this Code might be less effective against such hazards than against fires.
See Annex C for referenced documents on hazardous materials.
An assembly occupancy is an example of an occupancy where the goal of providing for reasonably safe emergency and nonemergency crowd movement has applicability. A detention or correctional occupancy is an example of an occupancy where emergency and nonemergency crowd movement is better addressed by detention and correctional facilities specialists than by this Code.
See 4.1.4 and Annex C for documents on hazardous materials.
Additional assumptions that need to be identified for a performance-based design are addressed in Chapter 5.
Protection against certain terrorist acts will generally require protection methods beyond those required by this Code.

A.4.4.2.3(1) As an example, Table 7.2.2.2.1.1(a) limits a new stair to having a maximum riser height of 7 in. (180 mm) and 12.2.5.6.6 limits a new aisle stair in an assembly occupancy to having a maximum riser height of 8 in. (205 mm), 9 in. (230 mm), or 11 in. (280 mm). The specific provisions of 12.2.5.6.6 are intended to govern the maximum riser height for the new aisle stairs in assembly occupancies, not the general riser height requirement of Table 7.2.2.2.1.1(a).

A.4.4.2.3(2) As an example, 7.1.3.2.1 requires an exit stair to be enclosed and separated from the remainder of the building by fire resistance-rated construction of at least one hour and 8.6.5 requires a minimum fire resistance rating of 1/2 hour for the enclosure of an existing floor opening. A existing hole in a floor used for a stair creates a vertical opening subject to the enclosure and protection requirements of 8.6.5. Where such stair is used as an exit stair, it is subject to the requirements of 7.1.3.2.1 for the separation and enclosure of exits. The case of a stair used as an exit stair is more specific than the case of a non-exit stair that creates a vertical opening. The provision of 7.1.3.2.1 governs with respect to the required fire resistance rating of the exit stair enclosure.

A.4.4.2.3(3) As an example, the provision of 11.8.2.2 that prohibits elevator lobby door locking in new high-rise buildings is more specific than the provision of 38.2.2.2.4 that permits elevator lobby exit access door-locking arrangements in accordance with 7.2.1.6.3 in new business occupancies. New high-rise business occupancy buildings are a specific subset of the general category of new business occupancy buildings. Extra provisions and limitations are mandated for new high-rise business occupancy buildings that are not mandated for new non-high-rise business occupancy buildings. The specific provision of 11.8.2.2 is intended to govern the locking of elevator lobby doors, not the general provision of 38.2.2.2.4.

Fire alarms alert occupants to initiate emergency procedures, facilitate orderly conduct of fire drills, and might initiate response by emergency services.
Systems encompass facilities or equipment and people. Included are fire/smoke detection, alarm, and communication systems plus the system status panels in emergency command centers; supervisory systems for various especially critical components (e.g., certain valves) of fire protection systems; certain signs; and the availability of trained staff, notably in health care occupancies.
See A.4.6.5.
In existing buildings, it is not always practical to strictly apply the provisions of this Code. Physical limitations can cause the need for disproportionate effort or expense with little increase in life safety. In such cases, the authority having jurisdiction needs to be satisfied that reasonable life safety is ensured.

In existing buildings, it is intended that any condition that represents a serious threat to life be mitigated by the application of appropriate safeguards. It is not intended to require modifications for conditions that do not represent a significant threat to life, even though such conditions are not literally in compliance with the Code.

An example of what is intended by 4.6.5 would be a historic ornamental guardrail baluster with spacing that does not comply with the 4 in. (100 mm) requirement. Because reducing the spacing would have minimal impact on life safety but could damage the historic character of the guardrail, the existing spacing might be approved by the authority having jurisdiction.

In some cases, the requirements for new construction are less restrictive, and it might be justifiable to permit an existing building to use the less restrictive requirements. However, extreme care needs to be exercised when granting such permission, because the less restrictive provision might be the result of a new requirement elsewhere in the Code. For example, in editions of the Code prior to 1991, corridors in new health care occupancies were required to have a 1-hour fire resistance rating. Since 1991, such corridors have been required only to resist the passage of smoke. However, this provision is based on the new requirement that all new health care facilities be protected throughout by automatic sprinklers. (See A.4.6.7.5.)
An example of what is intended by 4.6.7.4 and 4.6.7.5 follows. In a hospital that has 6 ft (1830 mm) wide corridors, such corridors cannot be reduced in width, even though the provisions for existing hospitals do not require 6 ft (1830 mm) wide corridors. However, if a hospital has 10 ft (3050 mm) wide corridors, they are permitted to be reduced to 8 ft (2440 mm) in width, which is the requirement for new construction. If the hospital corridor is 36 in. (915 mm) wide, it would have to be increased to 48 in. (1220 mm), which is the requirement for existing hospitals.
Fatal fires have occurred when, for example, a required stair has been closed for repairs or removed for rebuilding, or when a required automatic sprinkler system has been shut off to change piping.
See also NFPA 241.
Examples of such features include automatic sprinklers, fire alarm systems, standpipes, and portable fire extinguishers. The presence of a life safety feature, such as sprinklers or fire alarm devices, creates a reasonable expectation by the public that these safety features are functional. When systems are inoperable or taken out of service but the devices remain, they present a false sense of safety. Also, before taking any life safety features out of service, extreme care needs to be exercised to ensure that the feature is not required, was not originally provided as an alternative or equivalent, or is no longer required due to other new requirements in the current Code. It is not intended that the entire system or protection feature be removed. Instead, components such as sprinklers, initiating devices, notification appliances, standpipe hose, and exit systems should be removed to reduce the likelihood of relying on inoperable systems or features. Conversely, equipment, such as fire or smoke dampers, that is not obvious to the public should be able to be taken out of service if no longer required by this Code. Where a door that is not required to be fire protection-rated is equipped with a fire protection listing label, it is not the intent of 4.6.12.3 to require such door to be self- or automatic-closing due merely to the presence of the label.
The provisions of 4.6.13 do not require inherently noncombustible materials to be tested in order to be classified as noncombustible materials.

A.4.6.13.1(1) Examples of such materials include steel, concrete, masonry, and glass.

Materials subject to increase in combustibility or flame spread index beyond the limits herein established through the effects of age, moisture, or other atmospheric condition are considered combustible. (See NFPA 259 and NFPA 220.)
The purpose of emergency egress and relocation drills is to educate the participants in the fire safety features of the building, the egress facilities available, and the procedures to be followed. Speed in emptying buildings or relocating occupants, while desirable, is not the only objective. Prior to an evaluation of the performance of an emergency egress and relocation drill, an opportunity for instruction and practice should be provided. This educational opportunity should be presented in a nonthreatening manner, with consideration given to the prior knowledge, age, and ability of audience.

The usefulness of an emergency egress and relocation drill, and the extent to which it can be performed, depends on the character of the occupancy.

In buildings where the occupant load is of a changing character, such as hotels or department stores, no regularly organized emergency egress and relocation drill is possible. In such cases, the emergency egress and relocation drills are to be limited to the regular employees, who can be thoroughly schooled in the proper procedure and can be trained to properly direct other occupants of the building in case of emergency evacuation or relocation. In occupancies such as hospitals, regular employees can be rehearsed in the proper procedure in case of fire; such training is always advisable in all occupancies, regardless of whether regular emergency egress and relocation drills can be held.

If an emergency egress and relocation drill is considered merely as a routine exercise from which some persons are allowed to be excused, there is a grave danger that, in an actual emergency, the evacuation and relocation will not be successful. However, there might be circumstances under which all occupants do not participate in an emergency egress and relocation drill; for example, infirm or bedridden patients in a health care occupancy.
Fire is always unexpected. If the drill is always held in the same way at the same time, it loses much of its value. When, for some reason during an actual fire, it is not possible to follow the usual routine of the emergency egress and relocation drill to which occupants have become accustomed, confusion and panic might ensue. Drills should be carefully planned to simulate actual fire conditions. Not only should drills be held at varying times, but different means of exit or relocation areas should be used, based on an assumption that fire or smoke might prevent the use of normal egress and relocation avenues.
The written record required by this paragraph should include such details as the date, time, participants, location, and results of that drill.
Items to be considered in preparing an emergency action plan should include the following:
  1. Purpose of plan
  2. Building description, including certificate of occupancy
  3. Appointment, organization, and contact details of designated building staff to carry out the emergency duties
  4. Identification of events (man-made and natural) considered life safety hazards impacting the building
  5. Responsibilities matrix (role-driven assignments)
  6. Policies and procedures for those left behind to operate critical equipment
  7. Specific procedures to be used for each type of emergency
  8. Requirements and responsibilities for assisting people with disabilities
  9. Procedures for accounting for employees
  10. Training of building staff, building emergency response teams, and other occupants in their responsibilities
  11. Documents, including diagrams, showing the type, location, and operation of the building emergency features, components, and systems
  12. Practices for controlling life safety hazards in the building
  13. Inspection and maintenance of building facilities that provide for the safety of occupants
  14. Conducting fire and evacuation drills
  15. Interface between key building management and emergency responders
  16. Names or job titles of persons who can be contacted for further information or explanation of duties
  17. Post-event (including drill) critique/evaluation, as addressed in Chapter 9 of NFPA 1600
  18. Means to update the plan, as necessary

A.4.8.2.1(3) It is assumed that a majority of buildings will use a total evacuation strategy during a fire. It should be noted that evacuation from a building could occur for reasons other than a fire, but such other reasons are not the primary focus of the Code. As used herein, total evacuation is defined as the process in which all, or substantially all, occupants leave a building or facility in either an unmanaged or managed sequence or order. An alternative to total evacuation is partial evacuation, which can be defined as the process in which a select portion of a building or facility is cleared or emptied of its occupants while occupants in other portions mostly carry on normal activity. In either case, the evacuation process can be ordered or managed in accordance with an established priority in which some or all occupants of a building or facility clear their area and utilize means of egress routes. This is typically done so that the more-endangered occupants are removed before occupants in less-endangered areas. Alternative terms describing this sequencing or ordering of evacuation are staged evacuation and phased evacuation.

Table A.4.8.2.1(3) illustrates options for extent of management and extent of evacuation. Some of the options shown might not be appropriate. As noted in Table A.4.8.2.1(3), either total or partial evacuation can include staged (zoned) evacuation or phased evacuation, which is referred to as managed or controlled evacuation. It should also be noted that the evacuation process might not include relocation to the outside of the building but might instead include relocation to an area of refuge or might defend the occupants in place to minimize the need for evacuation.

Table A.4.8.2.1(3) Occupant Evacuation Strategies

Managed Sequence Unmanaged Sequence
Shelter in place No movement — Shelter in place upon direction No movement — Shelter in place per prior instruction
Relocation or partial evacuation Managed or controlled partial evacuation
• In-building relocation on same floor
• In-building relocation to different floors
• Occupants of some floors leave building
Unmanaged movement
Total evacuation Managed or controlled total evacuation Unmanaged or controlled total evacuation

The different methods of evacuation are also used in several contexts throughout the Code. Though most of the methods of evacuation are not specifically defined or do not have established criteria, various sections of the Code promulgate them as alternatives to total evacuation. The following sections discuss these alternatives in more detail:

  1. Section 4.7 — Provides requirements for fire and relocation drills
  2. 7.2.12 — Provides requirements for area of refuge
  3. 7.2.4 — Provides requirements for horizontal exits
  4. 9.6.3.6 — Provides the alarm signal requirements for different methods of evacuation
  5. 9.6.3.9 — Permits automatically transmitted or live voice evacuation or relocation instructions to occupants and requires them in accordance with NFPA 72
  6. 14.3.4.2.3 (also Chapter 15) — Describes alternative protection systems in educational occupancies
  7. 18.1.1.2/18.1.1.3/Section 18.7 (also Chapter 19) — Provide methods of evacuation for health care occupancies
  8. Chapters 22 and 23 — Provide methods of evacuation for detention and correctional occupancies, including the five groups of resident user categories
  9. Chapters 32 and 33 — Provide methods of evacuation for residential board and care occupancies
  10. 32.1.5/33.1.5 — For residential board and care occupancies, state that "no means of escape or means of egress shall be considered as complying with the minimum criteria for acceptance, unless emergency evacuation drills are regularly conducted"
  11. 40.2.5.2.2 — For industrial occupancies, states that "ancillary facilities in special-purpose industrial occupancies where delayed evacuation is anticipated shall have not less than a 2-hour fire resistance-rated separation from the predominant industrial occupancy and shall have one means of egress that is separated from the predominant industrial occupancy by 2-hour fire resistance-rated construction"

The method of evacuation should be accomplished in the context of the physical facilities, the type of activities undertaken, and the provisions for the capabilities of occupants (and staff, if available). Therefore, in addition to meeting the requirements of the Code, or when establishing an equivalency or a performance-based design, the following recommendations and general guidance information should be taken into account when designing, selecting, executing, and maintaining a method of evacuation:

  1. When choosing a method of evacuation, the available safe egress time (ASET) must always be greater than the required safe egress time (RSET).
  2. The occupants' characteristics will drive the method of evacuation. For example, occupants might be incapable of evacuating themselves because of age, physical or mental disabilities, physical restraint, or a combination thereof. However, some buildings might be staffed with people who could assist in evacuating. Therefore, the method of evacuation is dependent on the ability of occupants to move as a group, with or without assistance. For more information, see the definitions under the term Evacuation Capability in Chapter 3.
  3. An alternative method of evacuation might or might not have a faster evacuation time than a total evacuation. However, the priority of evacuation should be such that the occupants in the most danger are given a higher priority. This prioritization will ensure that occupants more intimate with the fire will have a faster evacuation time.
  4. Design, construction, and compartmentation are also variables in choosing a method of evacuation. The design, construction, and compartmentation should limit the development and spread of a fire and smoke and reduce the need for occupant evacuation. The fire should be limited to the room or compartment of fire origin. Therefore, the following factors need to be considered:
    1. Overall fire resistance rating of the building
    2. Fire-rated compartmentation provided with the building
    3. Number and arrangement of the means of egress
  5. Fire safety systems should be installed that complement the method of evacuation and should include consideration of the following:
    1. Detection of fire
    2. Control of fire development
    3. Confinement of the effects of fire
    4. Extinguishment of fire
    5. Provision of refuge or evacuation facilities, or both
  6. One of the most important fire safety systems is the fire alarm and communications system, particularly the notification system. The fire alarm system should be in accordance with NFPA 72 and should take into account the following:
    1. Initial notification of only the occupants in the affected zone(s) (e.g., zone of fire origin and adjacent zones)
    2. Provisions to notify occupants in other unaffected zones to allow orderly evacuation of the entire building
    3. Need for live voice communication
    4. Reliability of the fire alarm and communications system
  7. The capabilities of the staff assisting in the evacuation process should be considered in determining the method of evacuation.
  8. The ability of the fire department to interact with the evacuation should be analyzed. It is important to determine if the fire department can assist in the evacuation or if fire department operations hinder the evacuation efforts.
  9. Evacuation scenarios for hazards that are normally outside of the scope of the Code should be considered to the extent practicable. (See 4.3.1.)
  10. Consideration should be given to the desire of the occupants to self-evacuate, especially if the nature of the building or the fire warrants evacuation in the minds of the occupants. Self-evacuation might also be initiated by communication between the occupants themselves through face-to-face contact, mobile phones, and so forth.
  11. An investigation period, a delay in the notification of occupants after the first activation of the fire alarm, could help to reduce the number of false alarms and unnecessary evacuations. However, a limit to such a delay should be established before a general alarm is sounded, such as positive alarm sequence, as defined in NFPA 72.
  12. Consideration should be given to the need for an evacuation that might be necessary for a scenario other than a fire (e.g., bomb threat, earthquake).
  13. Contingency plans should be established in the event the fire alarm and communications system fail, which might facilitate the need for total evacuation.
  14. The means of egress systems should be properly maintained to ensure the dependability of the method of evacuation.
  15. Fire prevention policies or procedures, or both, should be implemented that reduce the chance of a fire (e.g., limiting smoking or providing fire-safe trash cans).
  16. The method of evacuation should be properly documented, and written forms of communication should be provided to all of the occupants, which might include sign postings throughout the building. Consideration should be given to the development of documentation for an operation and maintenance manual or a fire emergency action plan, or both.
  17. Emergency egress drills should be performed on a regular basis. For more information, see Section 4.7.
  18. The authority having jurisdiction should also be consulted when developing the method of evacuation.

Measures should be in place and be employed to sequence or control the order of a total evacuation, so that such evacuations proceed in a reasonably safe, efficient manner. Such measures include special attention to the evacuation capabilities and needs of occupants with disabilities, either permanent or temporary. For comprehensive guidance on facilitating life safety for such populations, go to www.nfpa.org. For specific guidance on emergency stair travel devices, see ANSI/RESNA ED-1, Emergency Stair Travel Devices Used by Individuals with Disabilities.

In larger buildings, especially high-rise buildings, it is recommended that all evacuations — whether partial or total — be managed to sequence or control the order in which certain occupants are evacuated from their origin areas and to make use of available means of egress. In high-rise buildings, the exit stairs, at any level, are designed to accommodate the egress flow of only a very small portion of the occupants — from only one or a few stories, and within a relatively short time period — on the order of a few minutes. In case of a fire, only the immediately affected floor(s) should be given priority use of the means of egress serving that floor(s). Other floors should then be given priority use of the means of egress, depending on the anticipated spread of the fire and its combustion products and for the purpose of clearing certain floors to facilitate eventual fire service operations. Typically, this means that the one or two floors above and below a fire floor will have secondary priority immediately after the fire floor. Depending on where combustion products move — for example, upward through a building with cool-weather stack effect — the next priority floors will be the uppermost occupied floors in the building.

Generally, in order to minimize evacuation time for most or all of a relatively tall building to be evacuated, occupants from upper floors should have priority use of exit stairs. For people descending many stories of stairs, this priority will maximize their opportunity to take rest stops without unduly extending their overall time to evacuate a building. Thus, the precedence behavior of evacuees should be that people already in an exit stair should normally not defer to people attempting to enter the exit stair from lower floors, except for those lower floors most directly impacted by a fire or other imminent danger. Notably, this is contrary to the often observed behavior of evacuees in high-rise building evacuations where lower floor precedence behavior occurs. (Similarly, in the most commonly observed behavior of people normally disembarking a passenger airliner, people within the aisle defer to people entering the aisle, so that the areas closest to the exit typically clear first.) Changing, and generally managing, the sequence or order in which egress occurs will require effectively informing building occupants and evaluating resulting performance in a program of education, training, and drills.

When designing the method of evacuation for a complex building, all forms of egress should be considered. For example, consideration could be given to an elevator evacuation system. An elevator evacuation system involves an elevator design that provides protection from fire effects so that elevators can be used safely for egress. See 7.2.13 and A.7.2.12.2.4 for more information.

For further guidance, see the following publications:

  1. SFPE Engineering Guide to Human Behavior in Fire, which provides information on occupant characteristics, response to fire cues, decision making in fire situations, and methods for predicting evacuation times
  2. NFPA Fire Protection Handbook, 20th edition, Section 1, Chapter 9, which provides good methodology for managing exposures and determining the method of evacuation
  3. NFPA Fire Protection Handbook, 20th edition, Section 20, which provides further commentary on methods of evacuation for different occupancies
  4. SFPE Handbook of Fire Protection Engineering, Volume II, Chapters 58-61, which provide an overview of some of the research on methods of evacuation and methods for predicting evacuation times
Emergency action plans are a critical component of assuring life safety in buildings. Life safety is the result of an interaction of technical and social systems within the building and in the community. Gathering information to evaluate the performance and effectiveness of emergency action plans is important for verifying system performance and as a basis for improvement. Such reports should be retained by building management and used to inform the process for revision of the building emergency action plan.

Following any drill or actual emergency or reported emergency occurring in the building, an after action report should be prepared by the building owner or designated representative to document the function of the building's life safety hardware, procedures, and occupant emergency organization.

For ordinary drills and reported emergencies, areas of success and areas for improvement should be identified.

For actual emergencies in the building, where there is major occupant movement, damage, or casualties, additional information should be collected. This includes questions concerning the event, as well as performance of life safety systems. It also identifies improvements in areas such as training, maintenance, interaction with local emergency response organizations, or occupant management. The reports from these significant events should be shared with the local emergency response organization.

Chapter 5 provides requirements for the evaluation of a performance-based life safety design. The evaluation process is summarized in Figure A.5.1.1.

FIGURE A.5.1.1 Performance-Based Life Safety Code Compliance Process.

Code Criteria. On the left side of Figure A.5.1.1 is input from the Code. The life safety goals have been stated in Section 4.1. The objectives necessary to achieve these goals are stated in Section 4.2. Section 5.2 specifies the performance criteria that are to be used to determine whether the objectives have been met.

Input. At the top of Figure A.5.1.1 is the input necessary to evaluate a life safety design.

The design specifications are to include certain retained prescriptive requirements, as specified in Section 5.3. All assumptions about the life safety design and the response of the building and its occupants to a fire are to be clearly stated as indicated in Section 5.4. Scenarios are used to assess the adequacy of the design. Eight sets of initiating events are specified for which the ensuing outcomes are to be satisfactory.

Performance Assessment. Appropriate methods for assessing performance are to be used per Section 5.6. Safety factors are to be applied to account for uncertainties in the assessment, as stated in Section 5.7. If the resulting predicted outcome of the scenarios is bounded by the performance criteria, the objectives have been met, and the life safety design is considered to be in compliance with this Code. Although not part of this Code, a design that fails to comply can be changed and reassessed, as indicated on the right side of Figure A.5.1.1.

Documentation. The approval and acceptance of a life safety design are dependent on the quality of the documentation of the process. Section 5.8 specifies a minimum set of documentation that is to accompany a submission.

The performance option of this Code establishes acceptable levels of risk to occupants of buildings and structures as addressed in Section 1.1. While the performance option of this Code does contain goals, objectives, and performance criteria necessary to provide an acceptable level of risk to occupants, it does not describe how to meet the goals, objectives, and performance criteria. Design and engineering are needed to develop solutions that meet the provisions of Chapter 5. The SFPE Engineering Guide to Performance-Based Fire Protection provides a framework for these assessments. Other useful references include the Australian Fire Engineering Guidelines and the British Standard Firesafety Engineering in Buildings.

A third-party reviewer is a person or group of persons chosen by the authority having jurisdiction to review proposed performance-based designs. The SFPE Guidelines for Peer Review in the Fire Protection Design Process provides a method for the initiation, scope, conduct, and report of a peer review of a fire protection engineering design.
For guidance on reviewing performance-based designs, see the SFPE Code Official's Guide to Performance-Based Design Review. Additional guidance on reviewing designs in which fire risk assessment is used can be found in NFPA 551.
Continued compliance with the goals and objectives of the Code involves many factors. The building construction — including openings, interior finish, and fire- and smoke-resistive construction — and the building and fire protection systems need to retain at least the same level of performance as is provided for the original design parameters. The use and occupancy should not change to the degree that assumptions made about the occupant characteristics, combustibility of furnishings, and existence of trained personnel are no longer valid. In addition, actions provided by other personnel, such as emergency responders, should not be diminished below the documented assumed levels. Also, actions needed to maintain reliability of systems at the anticipated level need to meet the initial design criteria.
One of the methods that follows can be used to avoid exposing occupants to untenable conditions.

Method 1. The design team can set detailed performance criteria that ensure that occupants are not incapacitated by fire effects. The SFPE Engineering Guide to Performance-Based Fire Protection describes a process of establishing tenability limits.

The guide references D. A. Purser, "Assessment of Hazards to Occupants from Smoke, Toxic Gasses, and Heat," Chapter 2/6, SFPE Handbook of Fire Protection Engineering, which describes a fractional effective dose (FED) calculation approach, which is also contained in NFPA 269. FED addresses the effects of carbon monoxide, hydrogen cyanide, carbon dioxide, hydrogen chloride, hydrogen bromide, and anoxia. It is possible to use the test data, combined with laboratory experience, to estimate the FED value that leads to the survival of virtually all people. This value is about 0.8.

There is a relationship between exposures leading to death and those leading to incapacitation. Kaplan [Kaplan and Hartzell, Journal of Fire Sciences, 2:286-305 (1984)] found that rodent susceptibility is similar to that of humans and that for the narcotic gases, CO and HCN, incapacitation is estimated to occur at one-third to one-half of the lethal exposure. A set of very large statistical studies on human lethality associated with carbon monoxide involving almost 5000 fatalities (Hirschler et al., "Carbon monoxide and human lethality: Fire and non-fire studies," Elsevier, 1993) showed that the vast majority of fire deaths are attributable to carbon monoxide poisoning, which results in lethality at levels as low as 25 percent carboxyhemoglobin (much lower than previously believed) without requiring the effect of additional toxicants. This work was also confirmed by Gann [Gann et al., Fire and Materials, 18:193 (1994)], who also found that carbon monoxide dominates the lethality of fire smoke, since most fire deaths occur remote from the fire room in fires that have proceeded past flashover. Thus, if an FED value of 0.8 were used for a nonlethal exposure, an FED of 0.3 would be reasonable for a nonincapacitating exposure.

If the authority having jurisdiction or the design professional is concerned with potential toxic fire effects, other than those addressed by the FED procedure as documented, the calculation procedure can be expanded by adding additional terms to the FED equation, with each term expressed as a ratio. The numerator of the ratio is the cumulative exposure to that fire effect, measured as an integral of the product of instantaneous exposure (concentration for toxic products) and time. The denominator of the ratio is the quantity of cumulative exposure for which FED equals the chosen threshold value (i.e., 0.8 or 0.3) based on that fire effect alone. A complete analysis of tenability requires consideration of tenability criteria for thermal effects (convected heat and radiated heat) and smoke obscuration, as well as those for smoke toxicity, and an example of the application of such criteria is shown in ASTM E2280, Standard Guide for Fire Hazard Assessment of the Effect of Upholstered Seating Furniture Within Patient Rooms of Health Care Facilities.

For buildings where an unusually large fraction of the occupants are especially vulnerable, the calculation procedure for the smoke toxicity incapacitating criterion should be modified to use FED values lower than 0.8 or 0.3.

Method 2. For each design fire scenario and the design specifications, conditions, and assumptions, the design team can demonstrate that each room or area will be fully evacuated before the smoke and toxic gas layer in that room descends to a level lower than 6 ft (1830 mm) above the floor. The timing of such an evacuation means that no occupant is exposed to fire effects. Such an evacuation requires calculation of the locations, movement, and behavior of occupants, because fire effects and occupants are separated by moving the occupants. A level of 60 in. (1525 mm) is often used in calculations, but, at that level, a large fraction of the population would not be able to stand, walk, or run normally and still avoid inhalation of toxic gases. They would have to bend over or otherwise move their heads closer to the floor level.

Method 3. For each design fire scenario and the design specifications and assumptions, the design team can demonstrate that the smoke and toxic gas layer will not descend to a level lower than 6 ft (1830 mm) above the floor in any occupied room. The advantage of this procedure is that it conservatively ensures that no occupant is exposed to fire effects, regardless of where occupants are located or where they move. This eliminates the need for calculations regarding occupants, including those for their behavior, movement locations, pre-fire characteristics, and reactions to fire effects. This procedure is even more conservative and simpler than the procedure in Method 2, because it does not allow fire effects in occupied rooms to develop to a point where people could be affected at any time during the fire.

Method 4. For each design fire scenario and the design specifications and assumptions, the design team can demonstrate that no fire effects will reach any occupied room. The advantage of this procedure is that it eliminates the need for calculations regarding occupants, including those for their behavior, movement, locations, pre-fire characteristics, and reactions to fire effects. A further advantage is that it also eliminates the need for some of the modeling of fire effects, because it is not necessary to model the filling of rooms, only the spread of fire effects to those rooms. This procedure is even more conservative and simpler than the procedures in Methods 2 and 3, because it does not allow any fire effects in occupied rooms.

This requirement applies both to systems and features required by the Code that reference applicable standards and to any additional systems or features included in the design at the discretion of the design team. The referenced standards are hereby expected to state maintenance, testing, and other requirements needed to provide positive assurance of an acceptable level of reliability. The referenced standards themselves might be prescriptive- or performance-based.
The design specifications and other conditions form the input to evaluation of proposed designs (see Section 5.6). Where a specification or condition is not known, a reasonable estimation is permitted. However, the design team must take steps to ensure that the estimation is valid during the life of the building. Any estimations need to be documented. (See Section 5.8.)
Systems addressed by this requirement include automatic fire suppression systems and fire alarm systems. Performance issues that need to be documented might include response time indexes, discharge densities, and distribution patterns. Calculations should not include an unlimited supply of extinguishing agent if only a limited supply will be provided in the actual structure or building.

Emergency procedures addressed by this requirement might be of two types. The design team could include documentation from buildings that are operationally very similar, along with documented operational performance measures tied to the recruitment and training of emergency team personnel. Where such data are unavailable, or where the proposed design differs significantly from other buildings, the design could be based on detailed analyses of the decisions and tasks that need to be performed by emergency personnel, using plausible conservative assumptions about the occupant characteristics and training of those personnel.

Examples of design features that might be incorporated to modify expected occupant characteristics include training, use of staff to assist with notification and movement, or type of notification appliance used.
The four basic characteristics — sensibility, reactivity, mobility, and susceptibility — comprise a minimum, exhaustive set of mutually exclusive performance characteristics of people in buildings that can affect a fire safety system's ability to meet life safety objectives. The characteristics are briefly described as follows:
  1. Sensibility to physical cues, which is the ability to sense the sounding of an alarm and can also include discernment and discrimination of visual and olfactory cues in addition to auditory emanations from the fire itself
  2. Reactivity, which is the ability to interpret cues correctly and take appropriate action and can be a function of cognitive capacity, speed of instinctive reaction, or group dynamics; might need to consider reliability or likelihood of a wrong decision, as in situations where familiarity with the premises influences wayfinding
  3. Mobility (speed of movement), which is determined by individual capabilities, as well as crowding phenomena, such as arching at doorways
  4. Susceptibility to products of combustion, which includes metabolism, lung capacity, pulmonary disease, allergies, or other physical limitations that affect survivability in a fire environment

In application, as with the use of computer evacuation models, assumptions can address a larger number of factors that are components of the basic performance characteristics, including the following:

  1. Alertness — condition of being awake/asleep, can depend on time of day
  2. Responsiveness — ability to sense cues and react
  3. Commitment — degree to which occupant is committed to an activity underway before the alarm
  4. Focal point — point at which an occupant's attention is focused (e.g., to front of classroom, stage, or server in business environment)
  5. Physical and mental capabilities — influence on ability to sense, respond, and react to cues; might be related to age or disability
  6. Role — influence on whether occupant will lead or follow others
  7. Familiarity — influence of time spent in building or participation in emergency training
  8. Social affiliation — extent to which an occupant will act/ react as an individual or as a member of a group
  9. Condition over the course of the fire — effects, both physiological and psychological, of the fire and its combustion products on each occupant

For a more detailed explanation of occupant characteristics, see the SFPE Engineering Guide to Human Behavior in Fire. Occupant characteristics that are discussed in the guide include the following:

  1. Population numbers and density
  2. Condition of being alone or with others
  3. Familiarity with the building
  4. Distribution and activities
  5. Alertness
  6. Physical and cognitive ability
  7. Social affiliation
  8. Role and responsibility
  9. Location
  10. Commitment
  11. Focal point
  12. Occupant condition
  13. Gender
  14. Culture
  15. Age
The number of people expected to be contained in a room or area should be based on the occupant load factor specified in Table 7.3.1.2 or other approved sources.
For example, in hospitals, staff characteristics such as number, location, quality, and frequency of training should be considered.
Design proposals need to state explicitly any design specifications or estimations regarding building fire safety plans, inspection programs, or other ongoing programs whose performance is necessary for the building, when occupied and operational, to meet the stated goals and objectives. Programs of interest include any maintenance, training, labeling, or certification programs required to ensure operational status or reliability in building systems or features.
The design elements required to be excluded by 5.4.9 include those regarding the interrelations between the performance of building elements and systems, occupant behavior, or emergency response actions that conflict with each other. For each fire scenario, care needs to be taken to ensure that conflicts in actions do not occur. Typical conflicts could include the following:
  1. Assuming a fire door will remain closed during the fire to contain smoke while this same door is used by occupants during egress from the area
  2. Assuming fire apparatus will arrive immediately from a distant location to provide water to fire department connections and similar situations

For example, an assumption that compartmentation blocking the passage of fire and smoke will be maintained at the door to a stairwell cannot be paired with an assumption that evacuation through that door will extend over many minutes.

The provisions required by 5.4.10 to be documented include those that are in excess of basic requirements covered by referenced codes and standards, typical design requirements, and operating procedures. Such provisions include the following:
  1. More frequent periodic testing and maintenance to increase the reliability of fire protection systems
  2. Redundant systems to increase reliability
  3. On-site guard service to enhance detection of fires and aid in fire response procedures
  4. Staff training
  5. Availability and performance of emergency response personnel
  6. Other factors
Design fire scenarios define the challenge a building is expected to withstand. Design fire scenarios capture and limit value judgments on the type and severity of the fire challenge to which a proposed fire safety system needs to respond. The system includes any and all aspects of the proposed design that are intended to mitigate the effects of a fire, such as egress system, automatic detection and suppression, barriers, staff training, and placement of manual extinguishers.

Design fire scenarios come from two sources: those that are specified in 5.5.3.1 through 5.5.3.8, and those that are developed by the design team based on the unique characteristics of the building as required by 5.5.2. In most, if not all, cases, more than one design fire scenario will be developed to meet the requirements of 5.5.2.

Once the set of design fire scenarios is established, both those specified by 5.5.3.1 through 5.5.3.8 and those that are developed as required by 5.5.2, they need to be quantified into a format that can be used for the evaluation of proposed designs. The SFPE Engineering Guide to Performance-Based Fire Protection outlines a process and identifies tools and references that can be used at each step of this process.

The protection systems and features used to meet the challenge of the design fire scenario should be typical of, and consistent with, those used for other similar areas of the building. They should not be designed to be more effective in the building area addressed than in similar areas not included and that are, therefore, not explicitly evaluated.
It is desirable to consider a wide variety of different fire scenarios to evaluate the complete life safety capabilities of the building or structure. Fire scenarios should not be limited to a single or a couple of worst-case fire scenarios.

The descriptive terms used to indicate the rate of fire growth for the scenarios are intended to be generic. Use of t-squared fires is not required for any scenario.

An example of Design Fire Scenario 1 for a health care occupancy would involve a patient room with two occupied beds with a fire initially involving one bed and the room door open. This is a cursory example in that much of the explicitly required information indicated in 5.5.3.1 can be determined from the information provided in the example. Note that it is usually necessary to consider more than one scenario to capture the features and conditions typical of an occupancy.
Design Fire Scenario 2 examples include a fire involving ignition of gasoline as an accelerant in a means of egress, clothing racks in corridors, renovation materials, or other fuel configurations that can cause an ultrafast fire. The means of egress chosen is the doorway with the largest egress capacity among doorways normally used in the ordinary operation of the building. The baseline occupant characteristics for the property are assumed. At ignition, doors are assumed to be open throughout the building.
An example of Design Fire Scenario 3 is a fire in a storage room adjacent to the largest occupiable room in the building. The contents of the room of fire origin are specified to provide the largest fuel load and the most rapid growth in fire severity consistent with the normal use of the room. The adjacent occupiable room is assumed to be filled to capacity with occupants. Occupants are assumed to be somewhat impaired in whatever form is most consistent with the intended use of the building. At ignition, doors from both rooms are assumed to be open. Depending on the design, doorways connect the two rooms or they connect via a common hallway or corridor.

For purposes of this scenario, an occupiable room is a room that might contain people; that is, a location within a building where people are typically found.

An example of Design Fire Scenario 4 is a fire originating in a concealed wall or ceiling space adjacent to a large, occupied function room. Ignition involves concealed combustibles, including wire or cable insulation and thermal or acoustical insulation. The adjacent function room is assumed to be occupied to capacity. The baseline occupant characteristics for the property are assumed. At ignition, doors are assumed to be open throughout the building.
An example of Design Fire Scenario 5 is a cigarette fire in a trash can. The trash can is close enough to room contents to ignite more substantial fuel sources but is not close enough to any occupant to create an intimate-with-ignition situation. If the intended use of the property involves the potential for some occupants to be incapable of movement at any time, the room of origin is chosen as the type of room likely to have such occupants, filled to capacity with occupants in that condition. If the intended use of the property does not involve the potential for some occupants to be incapable of movement, the room of origin is chosen to be an assembly or function area characteristic of the use of the property, and the trash can is placed so that it is shielded by furniture from suppression systems. At ignition, doors are assumed to be open throughout the building.
An example of Design Fire Scenario 6 is a fire originating in the largest fuel load of combustibles possible in normal operation in a function or assembly room, or in a process/manufacturing area, characteristic of the normal operation of the property. The configuration, type, and geometry of the combustibles are chosen so as to produce the most rapid and severe fire growth or smoke generation consistent with the normal operation of the property. The baseline occupant characteristics for the property are assumed. At ignition, doors are assumed to be closed throughout the building.

This scenario includes everything from a big couch fire in a small dwelling to a rack fire in combustible liquids stock in a big box retail store.

An example of Design Fire Scenario 7 is an exposure fire. The initiating fire is the closest and most severe fire possible consistent with the placement and type of adjacent properties and the placement of plants and combustible adornments on the property. The baseline occupant characteristics for the property are assumed.

This category includes wildlands/urban interface fires and exterior wood shingle problems, where applicable.

Design Fire Scenario 8 addresses a set of conditions with a typical fire originating in the building with any one passive or active fire protection system or feature being ineffective. Examples include unprotected openings between floors or between fire walls or fire barrier walls, failure of rated fire doors to close automatically, shutoff of sprinkler system water supply, nonoperative fire alarm system, inoperable smoke management system, or automatic smoke dampers blocked open. This scenario should represent a reasonable challenge to the other building features provided by the design and presumed to be available.

The concept of a fire originating in ordinary combustibles is intentionally selected for this scenario. This fire, although presenting a realistic challenge to the building and the associated building systems, does not represent the worst-case scenario or the most challenging fire for the building. Examples include the following:

  1. Fire originating in ordinary combustibles in the corridor of a patient wing of a hospital under the following conditions:
    1. Staff is assumed not to close any patient room doors upon detection of fire.
    2. The baseline occupant characteristics for the property are assumed, and the patient rooms off the corridor are assumed to be filled to capacity.
    3. At ignition, doors to patient rooms are not equipped with self-closing devices and are assumed to be open throughout the smoke compartment.
  2. Fire originating in ordinary combustibles in a large assembly room or area in the interior of the building under the following conditions:
    1. The automatic suppression systems are assumed to be out of operation.
    2. The baseline occupant characteristics for the property are assumed, and the room of origin is assumed to be filled to capacity.
    3. At ignition, doors are assumed to be closed throughout the building.
  3. Fire originating in ordinary combustibles in an unoccupied small function room adjacent to a large assembly room or area in the interior of the building under the following conditions:
    1. The automatic detection systems are assumed to be out of operation.
    2. The baseline occupant characteristics for the property are assumed, the room of origin is assumed to be unoccupied, and the assembly room is assumed to be filled to capacity.
    3. At ignition, doors are assumed to be closed throughout the building.

A.5.5.3.8(3) The exemption is applied to each active or passive fire protection system individually and requires two different types of information to be developed by analysis and approved by the authority having jurisdiction. System reliability is to be analyzed and accepted. Design performance in the absence of the system is also to be analyzed and accepted, but acceptable performance does not require fully meeting the stated goals and objectives. It might not be possible to meet fully the goals and objectives if a key system is unavailable, and yet no system is totally reliable. The authority having jurisdiction will determine which level of performance, possibly short of the stated goals and objectives, is acceptable, given the very low probability (i.e., the system's unreliability probability) that the system will not be available.

The SFPE Engineering Guide to Performance-Based Fire Protection outlines a process for evaluating whether trial designs meet the performance criteria during the design fire scenarios. Additional information on reviewing the evaluation of a performance-based design can be found in the SFPE Code Official's Guide to Performance-Based Design Review.

The procedures described in Sections 5.2 and 5.4 identify required design fire scenarios among the design fire scenarios within which a proposed fire safety design is required to perform and the associated untenable conditions that are to be avoided in order to maintain life safety. Section 5.6 discusses methods that form the link from the scenarios and criteria to the goals and objectives.

Assessment methods are used to demonstrate that the proposed design will achieve the stated goals/objectives by providing information indicating that the performance criteria of Section 5.2 can be adequately met. Assessment methods are permitted to be either tests or modeling.

Tests. Test results can be directly used to assess a fire safety design when they accurately represent the scenarios developed by using Section 5.4 and provide output data matching the performance criteria in Section 5.2. Because the performance criteria for this Code are stated in terms of human exposure to lethal fire effects, no test will suffice. However, tests will be needed to produce data for use in models and other calculation methods.

Standardized Tests. Standardized tests are conducted on various systems and components to determine whether they meet some predetermined, typically prescriptive criteria. Results are given on a pass/fail basis — the test specimen either does or does not meet the pre-established criteria. The actual performance of the test specimen is not usually recorded.

Scale. Tests can be either small, intermediate, or full scale. Small-scale tests are used to test activation of detection and suppression devices and the flammability and toxicity of materials. Usually, the item to be tested is placed within the testing device or apparatus. Intermediate-scale tests can be used to determine the adequacy of system components — for example, doors and windows — as opposed to entire systems. The difference between small- and intermediate-scale tests is usually one of definition provided by those conducting the test. Full-scale tests are typically used to test building and structural components or entire systems. The difference between intermediate- and large-scale tests is also subject to the definition of those performing the test. Full-scale tests are intended to most closely depict performance of the test subject as installed in the field; that is, most closely represent real world performance.

Full-scale building evacuations can provide information on how the evacuation of a structure is likely to occur for an existing building with a given population without subjecting occupants to the real physical or psychological effects of a fire.

Data Uses. The data obtained from standardized tests have three uses for verification purposes. First, the test results can be used instead of a model. This use is typically the role of full-scale test results. Second, the test results can be used as a basis for validating the model. The model predictions match well with the test results. Therefore, the model can be used in situations similar to the test scenario. Third, the test results can be used as input to models. This is typically the use of small-scale tests, specifically flammability tests.

Start-Up Test. Start-up test results can be used to demonstrate that the fire safety system performs as designed. The system design might be based on modeling. If the start-up test indicates a deficiency, the system needs to be adjusted and retested until it can be demonstrated that the design can meet the performance criteria. Typically, start-up tests apply only to the installation to which they are designed.

Experimental Data. Experimental data from nonstandardized tests can be used when the specified scenario and the experimental setup are similar. Typically, experimental data are applicable to a greater variety of scenarios than are standardized test results.

Human and Organizational Performance Tests. Certain tests determine whether inputs used to determine human performance criteria remain valid during the occupancy of a building. Tests of human and organizational performance might include any of the following:

  1. Measuring evacuation times during fire drills
  2. Querying emergency response team members to determine whether they know required procedures
  3. Conducting field tests to ensure that emergency response team members can execute tasks within predetermined times and accuracy limits

Design proposals should include descriptions of any tests needed to determine whether stated goals, objectives, and performance criteria are being met.

Modeling. Models can be used to predict the performance criteria for a given scenario. Because of the limitations on using only tests for this purpose, models are expected to be used in most, if not all, performance-based design assessments.

The effect of fire and its toxic products on the occupants can be modeled, as can the movement and behavior of occupants during the fire. The term evacuation model will be used to describe models that predict the location and movements of occupants, and the term tenability model will be used to describe models that predict the effects on occupants of specified levels of exposure to fire effects.

Types of Fire Models. Fire models are used to predict fire-related performance criteria. Fire models can be either probabilistic or deterministic. Several types of deterministic models are available: computational fluid dynamics (CFD or field) models, zone models, purpose-built models, and hand calculations. Probabilistic fire models are also available but are less likely to be used for this purpose.

Probabilistic fire models use the probabilities as well as the severity of various events as the basis of evaluation. Some probabilistic models incorporate deterministic models, but are not required to do so. Probabilistic models attempt to predict the likelihood or probability that events or severity associated with an unwanted fire will occur, or they predict the "expected loss," which can be thought of as the probability-weighted average severity across all possible scenarios. Probabilistic models can be manifested as fault or event trees or other system models that use frequency or probability data as input. These models tend to be manifested as computer software, but are not required to do so. Furthermore, the discussion that follows under "Sources of Models" can also be applied to probabilistic models, although it concentrates on deterministic models.

CFD models can provide more accurate predictions than other deterministic models, because they divide a given space into many smaller-volume spaces. However, since they are still models, they are not absolute in their depiction of reality. In addition, they are much more expensive to use, because they are computationally intensive. Because of their expense, complexity, and intensive computational needs, CFD models require much greater scrutiny than do zone models.

It is much easier to assess the sensitivity of different parameters with zone models, because they generally run much faster and the output is much easier to interpret. Prediction of fire growth and spread has a large number of variables associated with it.

Purpose-built models (also known as stand-alone models) are similar to zone models in their ease of use. However, purpose-built models do not provide a comprehensive model. Instead, they predict the value of one variable of interest. For example, such a model can predict the conditions of a ceiling jet at a specified location under a ceiling, but a zone model would "transport" those conditions throughout the enclosure.

Purpose-built models might or might not be manifested as computer software. Models that are not in the form of software are referred to as hand calculations. Purpose-built models are, therefore, simple enough that the data management capabilities of a computer are not necessary. Many of the calculations are found in the SFPE Handbook of Fire Protection Engineering.

Types of Evacuation Models. Four categories of evacuation models can be considered: single-parameter estimation methods, movement models, behavioral simulation models, and tenability models.

Single-parameter estimation methods are generally used for simple estimates of movement time. They are usually based on equations derived from observations of movement in nonemergency situations. They can be hand calculations or simple computer models. Examples include calculation methods for flow times based on widths of exit paths and travel times based on travel distances. Sources for these methods include the SFPE Handbook of Fire Protection Engineering and the NFPA Fire Protection Handbook.

Movement models generally handle large numbers of people in a network flow similar to water in pipes or ball bearings in chutes. They tend to optimize occupant behavior, resulting in predicted evacuation times that can be unrealistic and far from conservative. However, they can be useful in an overall assessment of a design, especially in early evaluation stages where an unacceptable result with this sort of model indicates that the design has failed to achieve the life safety objectives.

Behavioral simulation models take into consideration more of the variables related to occupant movement and behavior. Occupants are treated as individuals and can have unique characteristics assigned to them, allowing a more realistic simulation of the design under consideration. However, given the limited availability of data for the development of these models, for their verification by their authors, or for input when using them, their predictive reliability is questionable.

Tenability Models. In general, tenability models will be needed only to automate calculations for the time-of-exposure effect equations referenced in A.5.2.2.

Other Models. Models can be used to describe combustion (as noted, most fire models only characterize fire effects), automatic system performance, and other elements of the calculation. There are few models in common use for these purposes, so they are not further described here.

Sources of Models. A compendia of computer fire models are found in the SFPE Computer Software Directory and in Olenick, S. and Carpenter, D., "An Updated International Survey of Computer Models for Fire and Smoke," Journal of Fire Protection Engineering, 13, 2, 2003, pp. 87-110. Within these references are models that were developed by the Building Fire Research Laboratory of the National Institute of Standards and Technology, which can be downloaded from the Internet at http://www.bfrl.nist.gov/864/fmabs.html. Evacuation models are discussed in the SFPE Handbook of Fire Protection Engineering and the NFPA Fire Protection Handbook.

Verification and validation. Models should undergo verification and validation to ensure that they are appropriate for their intended use. "Verification" is a check of the math used in the models. "Validation" is a check of the physics used in the model. The SFPE Guidelines for Substantiating a Fire Model for a Given Application provides a process for verifying and validating models.

The design professional should present the proposal, and the authority having jurisdiction, when deciding whether to approve a proposal, should consider the strength of the evidence presented for the validity, accuracy, relevance, and precision of the proposed methods. An element in establishing the strength of scientific evidence is the extent of external review and acceptance of the evidence by peers of the authors of that evidence.

Models have limitations. Most are not user friendly, and experienced users are able to construct more reasonable models and better interpret output than are novices. For these reasons, the third-party review and equivalency provisions of 5.1.4 and 5.3.3 are provided. The intent is not to discourage the use of models, only to indicate that they should be used with caution by those who are well versed in their nuances.

Input Data. The first step in using a model is to develop the input data. The heat release rate curve specified by the user is the driving force of a fire effects model. If this curve is incorrectly defined, the subsequent results are not usable. In addition to the smoldering and growth phases that will be specified as part of the scenario definition, two additional phases are needed to complete the input heat release rate curve — steady burning and burnout.

Steady burning is characterized by its duration, which is a function of the total amount of fuel available to be burned. In determining the duration of this phase, the designer needs to consider how much fuel has been assumed to be consumed in the smoldering and growth phases and how much is assumed to be consumed in the burnout phase that follows. Depending on the assumptions made regarding the amount of fuel consumed during burnout, the time at which this phase starts is likely to be easy to determine.

The preceding discussion assumes that the burning objects are solid (e.g., tables and chairs). If liquid or gaseous fuels are involved, the shape of the curve will be different. For example, smoldering is not relevant for burning liquids or gases, and the growth period is very short, typically measured in seconds. Peak heat release rate can depend primarily on the rate of release, on the leak rate (gases and liquid sprays), or on the extent of spill (pooled liquids). The steady burning phase is once again dependent on the amount of fuel available to burn. Like the growth phase, the burnout phase is typically short (e.g., closing a valve), although it is conceivable that longer times might be appropriate, depending on the extinguishment scenario.

Material properties are usually needed for all fuel items, both initial and secondary, and the enclosure surfaces of involved rooms or spaces.

For all fires of consequence, it is reasonable to assume that the fire receives adequate ventilation. If there is insufficient oxygen, the fire will not be sustained. An overabundance of oxygen is only a concern in special cases (e.g., hermetically sealed spaces) where a fire might not occur due to dilution of the fuel (i.e., a flammable mixture is not produced). Therefore, given that the scenarios of interest will occur in nonhermetically sealed enclosures, it is reasonable to assume that adequate ventilation is available and that, if a fire starts, it will continue to burn until it either runs out of fuel or is extinguished by other means. The only variable that might need to be assumed is the total vent width.

Maximum fire extent is affected by two geometric aspects: burning object proximity to walls and overall enclosure dimensions.

The room dimensions affect the time required for a room to flashover. For a given amount and type of fuel, under the same ventilation conditions, a small room will flashover before a large room. In a large room with a small amount of fuel, a fire will behave as if it is burning outside — that is, adequate oxygen for burning and no concentration of heat exist. If the fuel package is unchanged but the dimensions of the room are decreased, the room will begin to have an affect on the fire, assuming adequate ventilation. The presence of the relatively smaller enclosure results in the buildup of a hot layer of smoke and other products of combustion under the ceiling. This buildup, in turn, feeds more heat back to the seat of the fire, which results in an increase in the pyrolysis rate of the fuel and, thus, increases the amount of heat energy released by the fire. The room enclosure surfaces themselves also contribute to this radiation feedback effect.

Probabilistic data are expressed as either a frequency (units of inverse time) or a probability (unitless, but applicable to a stated period of time). An example of the former is the expected number of failures per year, and the range of the latter is between zero and one, inclusive. Probabilities can be either objective or subjective. Subjective probabilities express a degree of belief that an event will occur. Objective probabilities are based on historical data and can be expressed as a reliability of an item, such as a component or a system.

Procedures used to develop required input data need to preserve the intended conservatism of all scenarios and assumptions. Conservatism is only one means to address the uncertainty inherent in calculations and does not eliminate the need to consider safety factors, sensitivity analysis, and other methods of dealing with uncertainty. The SFPE Guidelines for Substantiating a Fire Model for a Given Application outlines a process for identifying and treating uncertainty and other inaccuracies introduced through the use of fire models.
An assessment method translates input data, which might include test specifications, parameters, or variables for modeling, or other data, into output data, which are measured against the performance criteria. Computer fire models should be evaluated to ensure that they are appropriate for their intended use in accordance with the SFPE Guidelines for Substantiating a Fire Model for a Given Application.
The assessment of precision required in 5.8.2 will require a sensitivity and uncertainty analysis, which can be translated into safety factors.

Sensitivity Analysis. The first run a model user makes should be labeled as the base case, using the nominal values of the various input parameters. However, the model user should not rely on a single run as the basis for any performance-based fire safety system design. Ideally, each variable or parameter that the model user made to develop the nominal input data should have multiple runs associated with it, as should combinations of key variables and parameters. Thus, a sensitivity analysis should be conducted that provides the model user with data that indicate how the effects of a real fire might vary and how the response of the proposed fire safety design might also vary.

The interpretation of a model's predictions can be a difficult exercise if the model user does not have knowledge of fire dynamics or human behavior.

Reasonableness Check. The model user should first try to determine whether the predictions actually make sense; that is, whether they do not upset intuition or preconceived expectations. Most likely, if the results do not pass this test, an input error has been committed.

Sometimes the predictions appear to be reasonable but are, in fact, incorrect. For example, a model can predict higher temperatures farther from the fire than closer to it. The values themselves might be reasonable; for example, they are not hotter than the fire, but they do not "flow" down the energy as expected.

A margin of safety can be developed using the results of the sensitivity analysis in conjunction with the performance criteria to provide the possible range of time during which a condition is estimated to occur.

Safety factors and margin of safety are two concepts used to quantify the amount of uncertainty in engineering analyses. Safety factors are used to provide a margin of safety and represent, or address, the gap in knowledge between the theoretically perfect model — reality — and the engineering models that can only partially represent reality.

Safety factors can be applied either to the predicted level of a physical condition or to the time at which the condition is predicted to occur. Thus, a physical or a temporal safety factor, or both, can be applied to any predicted condition. A predicted condition (i.e., a parameter's value) and the time at which it occurs are best represented as distributions. Ideally, a computer fire model predicts the expected or nominal value of the distribution. Safety factors are intended to represent the spread of the distributions.

Given the uncertainty associated with data acquisition and reduction, and the limitations of computer modeling, any condition predicted by a computer model can be thought of as an expected or nominal value within a broader range. For example, an upper layer temperature of 1110°F (600°C) is predicted at a given time. If the modeled scenario is then tested (i.e., full-scale experiment based on the computer model's input data), the actual temperature at that given time could be 1185°F or 1085°F (640°C or 585°C). Therefore, the temperature should be reported as 1110°F + 75°F/—25°F (600°C + 40°C/—15°C) or as a range of 1085°F to 1185°F (585°C to 640°C).

Ideally, predictions are reported as a nominal value, a percentage, or an absolute value. As an example, an upper layer temperature prediction could be reported as "1110°F (600°C), 55°F (30°C)," or "1110°F (600°C), 5 percent." In this case, the physical safety factor is 0.05 (i.e., the amount by which the nominal value should be degraded and enhanced). Given the state-of-the-art of computer fire modeling, this is a very low safety factor. Physical safety factors tend to be on the order of tens of percent. A safety factor of 50 percent is not unheard of.

Part of the problem in establishing safety factors is that it is difficult to state the percentage or range that is appropriate. These values can be obtained when the computer model predictions are compared to test data. However, using computer fire models in a design mode does not facilitate this comparison, due to the following:

  1. The room being analyzed has not been built yet.
  2. Test scenarios do not necessarily depict the intended design.

A sensitivity analysis should be performed, based on the assumptions that affect the condition of interest. A base case that uses all nominal values for input parameters should be developed. The input parameters should be varied over reasonable ranges, and the variation in predicted output should be noted. This output variation can then become the basis for physical safety factors.

The temporal safety factor addresses the issue of when a condition is predicted and is a function of the rate at which processes are expected to occur. If a condition is predicted to occur 2 minutes after the start of the fire, this prediction can be used as a nominal value. A process similar to that already described for physical safety factors can also be employed to develop temporal safety factors. In such a case, however, the rates (e.g., rates of heat release and toxic product generation) will be varied instead of absolute values (e.g., material properties).

The margin of safety can be thought of as a reflection of societal values and can be imposed by the authority having jurisdiction for that purpose. Because the time for which a condition is predicted will most likely be the focus of the authority having jurisdiction (e.g., the model predicts that occupants will have 5 minutes to safely evacuate), the margin of safety will be characterized by temporal aspects and tacitly applied to the physical margin of safety.

Escaping the harmful effects of fire (or mitigating them) is, effectively, a race against time. When assessing fire safety system designs based on computer model predictions, the choice of an acceptable time is important. When an authority having jurisdiction is faced with the predicted time of untenability, a decision needs to be made regarding whether sufficient time is available to ensure the safety of building occupants. The authority having jurisdiction is assessing the margin of safety. Is there sufficient time to get everyone out safely? If the authority having jurisdiction feels that the predicted egress time is too close to the time of untenability, the authority having jurisdiction can impose an additional period of time that the designer will have to incorporate into the system design. In other words, the authority having jurisdiction can impose a greater margin of safety than that originally proposed by the designer.

The SFPE Engineering Guide to Performance-Based Fire Protection describes the documentation that should be provided for a performance-based design.

Proper documentation of a performance-based design is critical to design acceptance and construction. Proper documentation will also ensure that all parties involved understand the factors necessary for the implementation, maintenance, and continuity of the fire protection design. If attention to details is maintained in the documentation, there should be little dispute during approval, construction, start-up, and use.

Poor documentation could result in rejection of an otherwise good design, poor implementation of the design, inadequate system maintenance and reliability, and an incomplete record for future changes or for testing the design forensically.

The sources, methodologies, and data used in performance-based designs should be based on technical references that are widely accepted and used by the appropriate professions and professional groups. This acceptance is often based on documents that are developed, reviewed, and validated under one of the following processes:
  1. Standards developed under an open consensus process conducted by recognized professional societies, codes or standards organizations, or governmental bodies
  2. Technical references that are subject to a peer review process and published in widely recognized peer-reviewed journals, conference reports, or other publications
  3. Resource publications, such as the SFPE Handbook of Fire Protection Engineering, which are widely recognized technical sources of information

The following factors are helpful in determining the acceptability of the individual method or source:

  1. Extent of general acceptance in the relevant professional community, including peer-reviewed publication, widespread citation in the technical literature, and adoption by or within a consensus document
  2. Extent of documentation of the method, including the analytical method itself, assumptions, scope, limitations, data sources, and data reduction methods
  3. Extent of validation and analysis of uncertainties, including comparison of the overall method with experimental data to estimate error rates, as well as analysis of the uncertainties of input data, uncertainties and limitations in the analytical method, and uncertainties in the associated performance criteria
  4. Extent to which the method is based on sound scientific principles
  5. Extent to which the proposed application is within the stated scope and limitations of the supporting information, including the range of applicability for which there is documented validation, and considering factors such as spatial dimensions, occupant characteristics, and ambient conditions, which can limit valid applications

In many cases, a method will be built from, and will include, numerous component analyses. Such component analyses should be evaluated using the same acceptability factors that are applied to the overall method, as outlined in items (1) through (5).

A method to address a specific fire safety issue, within documented limitations or validation regimes, might not exist. In such a case, sources and calculation methods can be used outside of their limitations, provided that the design team recognizes the limitations and addresses the resulting implications.

The technical references and methodologies to be used in a performance-based design should be closely evaluated by the design team and the authority having jurisdiction, and possibly by a third-party reviewer. The strength of the technical justification should be judged using criteria in items (1) through (5). This justification can be strengthened by the presence of data obtained from fire testing.

Documentation for modeling should conform to ASTM E1472, Standard Guide for Documenting Computer Software for Fire Models, although most, if not all, models were originally developed before this standard was promulgated. Information regarding the use of the model DETACT-QS can be found in the SFPE Engineering Guide-the Evaluation of the Computer Fire Model DETACT-QS.
Assembly occupancies might include the following:
  1. Armories
  2. Assembly halls
  3. Auditoriums
  4. Bowling lanes
  5. Club rooms
  6. College and university classrooms, 50 persons and over
  7. Conference rooms
  8. Courtrooms
  9. Dance halls
  10. Drinking establishments
  11. Exhibition halls
  12. Gymnasiums
  13. Libraries
  14. Mortuary chapels
  15. Motion picture theaters
  16. Museums
  17. Passenger stations and terminals of air, surface, underground, and marine public transportation facilities
  18. Places of religious worship
  19. Pool rooms
  20. Recreation piers
  21. Restaurants
  22. Skating rinks
  23. Special amusement buildings, regardless of occupant load
  24. Theaters

Assembly occupancies are characterized by the presence or potential presence of crowds with attendant panic hazard in case of fire or other emergency. They are generally or occasionally open to the public, and the occupants, who are present voluntarily, are not ordinarily subject to discipline or control. Such buildings are ordinarily not used for sleeping purposes. Special conference rooms, snack areas, and other areas incidental to, and under the control of, the management of other occupancies, such as offices, fall under the 50-person limitation.

Restaurants and drinking establishments with an occupant load of fewer than 50 persons should be classified as mercantile occupancies.

Occupancy of any room or space for assembly purposes by fewer than 50 persons in another occupancy, and incidental to such other occupancy, should be classified as part of the other occupancy and should be subject to the provisions applicable thereto.

For special amusement buildings, see 12.4.8 and 13.4.8.

Educational occupancies include the following:
  1. Academies
  2. Kindergartens
  3. Schools

An educational occupancy is distinguished from an assembly occupancy in that the same occupants are regularly present.

Day-care occupancies include the following:
  1. Adult day-care occupancies, except where part of a health care occupancy
  2. Child day-care occupancies
  3. Day-care homes
  4. Kindergarten classes that are incidental to a child day-care occupancy
  5. Nursery schools

In areas where public schools offer only half-day kindergarten programs, many child day-care occupancies offer state-approved kindergarten classes for children who need full-day care. As these classes are normally incidental to the day-care occupancy, the requirements of the day-care occupancy should be followed.

Health care occupancies include the following:
  1. Hospitals
  2. Limited care facilities
  3. Nursing homes

Occupants of health care occupancies typically have physical or mental illness, disease, or infirmity. They also include infants, convalescents, or infirm aged persons.

It is not the intent that occupants be considered to be incapable of self-preservation just because they are in a wheelchair or use assistive walking devices, such as a cane, a walker, or crutches. Rather, it is the intent to address emergency care centers that receive patients who have been rendered incapable of self-preservation due to the emergency, such as being rendered unconscious as a result of an accident or being unable to move due to sudden illness.
Detention and correctional occupancies include the following:
  1. Adult and juvenile substance abuse centers
  2. Adult and juvenile work camps
  3. Adult community residential centers
  4. Adult correctional institutions
  5. Adult local detention facilities
  6. Juvenile community residential centers
  7. Juvenile detention facilities
  8. Juvenile training schools

See A.22.1.1.1.6 and A.23.1.1.1.6.

Chapters 22 and 23 address the residential housing areas of the detention and correctional occupancy as defined in 3.3.196.5. Examples of uses, other than residential housing, include gymnasiums or industries.
The application statement of 24.1.1.1 limits each dwelling unit to being "occupied by members of a single family with not more than three outsiders." The Code does not define the term family. The definition of family is subject to federal, state, and local regulations and might not be restricted to a person or a couple (two people) and their children. The following examples aid in differentiating between a single-family dwelling and a lodging or rooming house:
  1. An individual or a couple (two people) who rent a house from a landlord and then sublease space for up to three individuals should be considered a family renting to a maximum of three outsiders, and the house should be regulated as a single-family dwelling in accordance with Chapter 24.
  2. A house rented from a landlord by an individual or a couple (two people) in which space is subleased to 4 or more individuals, but not more than 16, should be considered and regulated as a lodging or rooming house in accordance with Chapter 26.
  3. A residential building that is occupied by 4 or more individuals, but not more than 16, each renting from a landlord, without separate cooking facilities, should be considered and regulated as a lodging or rooming house in accordance with Chapter 26.
So-called apartment hotels should be classified as hotels, because they are potentially subject to the same transient occupancy as hotels. Transients are those who occupy accommodations for less than 30 days.
Rooms within dormitories intended for the use of individuals for combined living and sleeping purposes are guest rooms or guest suites. Examples of dormitories include college dormitories, fraternity and sorority houses, and military barracks.
The following are examples of facilities classified as residential board and care occupancies:
  1. Group housing arrangement for physically or mentally handicapped persons who normally attend school in the community, attend worship in the community, or otherwise use community facilities
  2. Group housing arrangement for physically or mentally handicapped persons who are undergoing training in preparation for independent living, for paid employment, or for other normal community activities
  3. Group housing arrangement for the elderly that provides personal care services but that does not provide nursing care
  4. Facilities for social rehabilitation, alcoholism, drug abuse, or mental health problems that contain a group housing arrangement and that provide personal care services but do not provide acute care
  5. Assisted living facilities
  6. Other group housing arrangements that provide personal care services but not nursing care
Mercantile occupancies include the following:
  1. Auction rooms
  2. Department stores
  3. Drugstores
  4. Restaurants with fewer than 50 persons
  5. Shopping centers
  6. Supermarkets

Office, storage, and service facilities incidental to the sale of merchandise and located in the same building should be considered part of the mercantile occupancy classification.

Business occupancies include the following:
  1. Airport traffic control towers (ATCTs)
  2. City halls
  3. College and university instructional buildings, classrooms under 50 persons, and instructional laboratories
  4. Courthouses
  5. Dentists' offices
  6. Doctors' offices
  7. General offices
  8. Outpatient clinics (ambulatory)
  9. Town halls

Doctors' and dentists' offices are included, unless of such character as to be classified as ambulatory health care occupancies. (See 3.3.196.1)

Birth centers should be classified as business occupancies if they are occupied by fewer than four patients, not including infants, at any one time; do not provide sleeping facilities for four or more occupants; and do not provide treatment procedures that render four or more patients, not including infants, incapable of self-preservation at any one time. For birth centers occupied by patients not meeting these parameters, see Chapter 18 or Chapter 19, as appropriate.

Service facilities common to city office buildings, such as newsstands, lunch counters serving fewer than 50 persons, barber shops, and beauty parlors are included in the business occupancy group.

City halls, town halls, and courthouses are included in this occupancy group, insofar as their principal function is the transaction of public business and the keeping of books and records. Insofar as they are used for assembly purposes, they are classified as assembly occupancies.

Industrial occupancies include the following:
  1. Drycleaning plants
  2. Factories of all kinds
  3. Food processing plants
  4. Gas plants
  5. Hangars (for servicing/maintenance)
  6. Laundries
  7. Power plants
  8. Pumping stations
  9. Refineries
  10. Sawmills
  11. Telephone exchanges

In evaluating the appropriate classification of laboratories, the authority having jurisdiction should treat each case individually, based on the extent and nature of the associated hazards. Some laboratories are classified as occupancies other than industrial; for example, a physical therapy laboratory or a computer laboratory.

Storage occupancies include the following:
  1. Barns
  2. Bulk oil storage
  3. Cold storage
  4. Freight terminals
  5. Grain elevators
  6. Hangars (for storage only)
  7. Parking structures
  8. Truck and marine terminals
  9. Warehouses

Storage occupancies are characterized by the presence of relatively small numbers of persons in proportion to the area.

Examples of uses that might be incidental to another occupancy include the following:
  1. Newsstand (mercantile) in an office building
  2. Giftshop (mercantile) in a hotel
  3. Small storage area (storage) in any occupancy
  4. Minor office space (business) in any occupancy
  5. Maintenance area (industrial) in any occupancy

A.6.1.14.1.3(2) Examples of uses that have occupant loads below the occupancy classification threshold levels include the following:

  1. Assembly use with fewer than 50 persons within a business occupancy
  2. Educational use with fewer than 6 persons within an apartment building.
For example, a common path of travel that occurs wholly in a business tenant space, in a multiple occupancy building containing assembly and business occupancies, should not have to meet the assembly occupancy common path of travel limitation.
Where the Code text states that the provision has applicability to the building, rather than just to the occupancy, the provision applies to the entire building, regardless of whether the separated occupancies form of protection is used. For example, the provision of 18.3.5.1 requires that the entire building housing a health care occupancy be sprinklered. Contrast that with the requirement of 20.3.4.1, which requires an ambulatory health care facility, and not the entire building, to be provided with a fire alarm system.
Under the provision of 6.2.1.3, any violation of the requirements of Chapters 11 through 42 for separation or protection of hazardous operation or storage would inherently involve violation of the other sections of the Code, unless additional egress facilities appropriate to high hazard contents were provided.
These classifications do not apply to the application of sprinkler protection classifications. See NFPA 13. Depending on the use of the space, the area might require special hazard protection in accordance with Section 8.7.

Also, these classifications do not apply to the application of hazardous materials classifications within NFPA 400. NFPA 101 primarily classifies hazards based on fire severity. NFPA 400 regulates contents through a different classification system, which takes into consideration physical hazards, health hazards, quantities, storage conditions, and use conditions.

See 4.1.3 and Annex C for referenced documents on hazardous materials.

Chapter 42 recognizes storage of noncombustible materials as low hazard. In other occupancies, it is assumed that, even where the actual contents hazard is normally low, there is sufficient likelihood that some combustible materials or hazardous operations will be introduced in connection with building repair or maintenance, or some psychological factor might create conditions conducive to panic, so that the egress facilities cannot safely be reduced below those specified for ordinary hazard contents.
Ordinary hazard classification represents the conditions found in most buildings and is the basis for the general requirements of this Code.

The fear of poisonous fumes or explosions is necessarily a relative matter to be determined on a judgment basis. All smoke contains some toxic fire gases but, under conditions of ordinary hazard, there should be no unduly dangerous exposure during the period necessary to escape from the fire area, assuming there are proper exits.

High hazard contents include occupancies where flammable liquids are handled or used or are stored under conditions involving possible release of flammable vapors; where grain dust, wood flour or plastic dust, aluminum or magnesium dust, or other explosive dusts are produced; where hazardous chemicals or explosives are manufactured, stored, or handled; where materials are processed or handled under conditions producing flammable flyings; and other situations of similar hazard.

Chapters 40 and 42 include detailed provisions on high hazard contents.

An installation of supplemental evacuation equipment is not recognized as a means of egress. Consequently, such equipment does not satisfy any requirement for minimum number of, capacity of, travel distance to, or remoteness of, means of egress.

A.7.1.3.2.1(1) In existing buildings, existing walls in good repair and consisting of lath and plaster, gypsum wallboard, or masonry units can usually provide satisfactory protection for the purposes of this requirement where a 1-hour fire resistance rating is required. Further evaluation might be needed where a 2-hour fire resistance rating is required. Additional guidelines can be found in Annex O of NFPA 914 and in the SFPE Handbook of Fire Protection Engineering.

A.7.1.3.2.1(3) In existing buildings, existing walls in good repair and consisting of lath and plaster, gypsum wallboard, or masonry units can usually provide satisfactory protection for the purposes of this requirement where a 1-hour fire resistance rating is required. Further evaluation might be needed where a 2-hour fire resistance rating is required. Additional guidelines can be found in Annex O of NFPA 914 and in the SFPE Handbook of Fire Protection Engineering.

A.7.1.3.2.1(6) It is not the intent to require the structural elements supporting outside stairs, or structural elements that penetrate within exterior walls or any other wall not required to have a fire resistance rating, to be protected by fire resistance-rated construction.

A.7.1.3.2.1(9) Means of egress from the level of exit discharge is permitted to pass through an exit stair enclosure or exit passageway serving other floors. Doors for convenience purposes and unrelated to egress also are permitted to provide access to and from exit stair enclosures and exit passageways, provided that such doors are from corridors or normally occupied spaces. It is also the intent of this provision to prohibit exit enclosure windows, other than approved vision panels in doors, that are not mounted in an exterior wall.

A.7.1.3.2.1(10)(b) The intent of this provision is to prevent the exit enclosure from being used as a vertical chase for building services. Penetrations for electrical wiring are permitted where the wiring serves equipment permitted by the authority having jurisdiction to be located within the exit enclosure.

A.7.1.3.2.1(10)(d) This provision will allow security cameras, public address systems, emergency communication systems, telephone repeaters and similar life safety devices in the exit enclosure, and wiring and similar pathways for such devices, to penetrate the fire barrier serving the exit enclosure. It is the intent of this provision to prevent the exit enclosure from being used as a vertical chase for building services.

This provision prohibits the use of exit enclosures for storage or for installation of equipment not necessary for safety. Occupancy is prohibited other than for egress, refuge, and access. The intent is that the exit enclosure essentially be "sterile" with respect to fire safety hazards.
See Chapters 12 through 42 for further limitations on interior wall and ceiling finish.
See Chapters 12 through 42 for further limitations on interior floor finish.
For the purpose of this requirement, projections include devices such as lighting equipment, emergency signaling equipment, environmental controls and equipment, security devices, signs, and decorations that are typically limited in area.
The foreseeable slip conditions are those that are likely to be present at the location of the walking surface during the use of the building or area. Examples of foreseeable conditions include a swimming pool deck and exterior means of egress, generally, that are likely to be wet.

Regarding the slip resistance of treads, it should be recognized that, when walking up or down stairs, a person's foot exerts a smaller horizontal force against treads than is exerted when walking on level floors. Therefore, materials used for floors that are acceptable as slip resistant (as described by ASTM F1637, Standard Practice for Safe Walking Surfaces) provide adequate slip resistance where used for stair treads. Such slip resistance includes the important leading edges of treads, the part of the tread that the foot first contacts during descent, which is the most critical direction of travel. If stair treads are wet, there is an increased danger of slipping, just as there is an increased danger of slipping on wet floors of similar materials. A small wash or drainage slope on exterior stair treads is, therefore, recommended to shed water. (See Templer, J. A., The Staircase: Studies of Hazards, Falls, and Safer Design, Cambridge, MA: MIT Press, 1992.)

Aside from the problems created for persons who are mobility impaired, small changes of elevations in floors are best avoided because of the increased occurrence of missteps where the presence of single steps, a series of steps, or a ramp is not readily apparent. Although small changes of elevation pose significant fall risks in the case of individual movement, they are even more undesirable where crowds traverse the area.

A contrasting marking stripe on each stepping surface can be helpful at the nosing or leading edge so that the location of each step is readily apparent, especially when viewed in descent. Such stripes should be not less than 1 in. (25 mm), but should not exceed 2 in. (51 mm), in width. Other methods could include a relatively higher level of lighting, contrasting colors, contrasting textures, highly prominent handrails, warning signs, a combination thereof, or other similar means. The construction or application of marking stripes should be such that slip resistance is consistent over the walking surface and no tripping hazard is created (see also A.7.2.2.3.3.2). Depending on the distractions of the surroundings, the familiarity of users with a particular small change of level, and especially the number of people that might be in a group traversing the change of level (thereby reducing visibility of the level changes), a strong argument can be made for the elimination of steps and ramps that might pose a risk of missteps.

Elements of the means of egress that might require protection with guards include stairs, landings, escalators, moving walks, balconies, corridors, passageways, floor or roof openings, ramps, aisles, porches, and mezzanines.

Escalators and moving walks, other than previously approved existing escalators and moving walks, are prohibited from serving as components of the required means of egress. Building occupants using the escalator at the time of fire or similar emergency must traverse some portion of the escalator to gain access to a required egress route. For those building occupants using the escalator, such travel along the escalator is part of their means of egress. The requirement that guards be provided at the open side of means of egress that exceed 30 in. (760 mm) above the floor or grade below is meant to be applied to escalators and moving walks.

A proper means of egress allows unobstructed travel at all times. Any type of barrier including, but not limited to, the accumulations of snow and ice in those climates subject to such accumulations is an impediment to free movement in the means of egress. Another example of an obstruction or impediment to full instant use of means of egress is any security device or system that emits any medium that could obscure a means of egress. It is, however, recognized that obstructions occur on a short-duration basis. In these instances, awareness training should be provided to ensure that blockages are kept to a minimum and procedures are established for the control and monitoring of the area affected.
Figure A.7.2.1.2.1(a) and Figure A.7.2.1.2.1(b) illustrate the method of measuring clear width for doors.

FIGURE A.7.2.1.2.1(a) Minimum Clear Width.

FIGURE A.7.2.1.2.1(b) Minimum Clear Width with Permitted Obstructions.

In cases where a chapter requires a door width, for example, of not less than 36 in. (915 mm), this requirement can be met by a door leaf of the minimum specified width if the term clear width does not appear as part of the minimum width requirement. A pair of cross-corridor doors subject to such a requirement would be judged under the following criteria:

  1. Each door leaf is required to be not less than 36 in. (915 mm) in width.
  2. The pair of doors is required to provide sufficient, clear, unobstructed width (which will be less than the door leaf width measurement) to handle its assigned occupant load, based on a calculation using the appropriate egress capacity factor in Table 7.3.3.1.

Where swinging doors do not open at least 90 degrees, the clear width of the doorway should be measured between the face of the door and the stop.

It is not the intent to regulate projections above the 6 ft 8 in. (2030 mm) height.

Figure A.7.2.1.2.2(a) and Figure A.7.2.1.2.2(b) illustrate the method of measuring egress capacity width for purposes of calculating door egress capacity.

FIGURE A.7.2.1.2.2(a) Door width for — Egress Capacity.

FIGURE A.7.2.1.2.2(b) Door Width — Egress Capacity with Permitted Obstructions.

A.7.2.1.2.3.2(2) A example of a room that is "not required to be accessible to persons with severe mobility impairments" is one that is not required to be accessible by NFPA 5000, Chapter 10.

A.7.2.1.2.3.2(3) A example of a room that is "not required to be accessible to persons with severe mobility impairments" is one that is not required to be accessible by NFPA 5000, Chapter 10.

A.7.2.1.2.3.2(9) The relative egress carrying capacity of door openings and stairs is based on the two-to-three ratio used in Table 7.3.3.1 to help balance the capacity of various egress elements and ensure that downstream egress facilities do not form a bottleneck or constriction to flow. For example, a stairway with a nominal width of 56 in. (1420 mm) should be served by an exit discharge door with a minimum width opening of 37 in. (940 mm) if only one discharge door is provided. It might be advantageous for two discharge doors to serve such a stairway, each with a more typical clear opening width of 32 in. (810 mm). This would facilitate access, into the exit, of fire fighters and other emergency responders without causing undue interference to evacuees attempting to transition from the stair to the exit discharge door.

Where doors are subject to two-way traffic, or where their opening can interfere with pedestrian traffic, an appropriately located vision panel can reduce the chance of accidents.

Swinging doors in horizontal- or vertical-rolling partitions should be permitted in a means of egress where the following criteria are met:

  1. The door or doors comply with 7.2.1.4.
  2. The partition in which the doors are mounted complies with the applicable fire protection rating and closes upon smoke detection or power failure at a speed not exceeding 9 in./s (230 mm/s) and not less than 6 in./s (150 mm/s).
  3. The doors mounted in the partition are self-closing or automatic-closing in accordance with 7.2.1.8.
See 7.4.2.1.2 and 7.4.2.2.2 for door swing direction requirements for working space about electrical equipment.
The requirements of 7.2.1.4.3 are not intended to apply to the swing of cross-corridor doors, such as smoke barrier doors and horizontal exits. Neither are the requirements intended to apply to doors from rooms that are typically unoccupied, such as janitor's closets, electrical closets, or telecommunications closets.
Some fire door assemblies are listed for use with fire pins or fusible links that render the door leaf release inoperative upon exposure to elevated temperature during a fire. The door leaf release mechanism is made inoperative where conditions in the vicinity of the door opening become untenable for human occupancy, and such door opening no longer provides a viable egress path.
Where the entrance consists of an exterior vestibule, the locking arrangement should be permitted on the egress side of either the interior or exterior door of the vestibule.

A.7.2.1.5.6(5) Separate power supplies might be provided to the electronic lock and the releasing hardware. In this case, it is critical that the lock be arranged to release upon loss of power to the releasing hardware to ensure occupants can egress in the event of a power failure.

It is intended that the re-entry provisions apply only to enclosed exit stairs, not to outside stairs. This arrangement makes it possible to leave the stairway at such floor if the fire renders the lower part of the stair unusable during egress or if the occupants seek refuge on another floor.
Examples of devices that might be arranged to release latches include knobs, levers, and bars. This requirement is permitted to be satisfied by the use of conventional types of hardware, whereby the door is released by turning a lever, knob, or handle or by pushing against a bar, but not by unfamiliar methods of operation, such as a blow to break glass. It is also within the intent of this requirement that switches integral to traditional doorknobs, lever handles, or bars, and that interrupt the power supply to an electromagnetic lock, be permitted, provided that they are affixed to the door leaf. The operating devices should be capable of being operated with one hand and should not require tight grasping, tight pinching, or twisting of the wrist to operate.
Examples of devices that, when used with a latch, can be arranged to require not more than one additional releasing operation include night latches, dead bolts, and security chains.
Examples of devices prohibited by this requirement include locks, padlocks, hasps, bars, chains, or combinations thereof.
None of the special locking arrangements addressed in 7.2.1.6 are intended to allow credentialed egress, request to exit, or similar provisions, where an occupant cannot leave the building without swiping a card through a reader. Where such an arrangement is desired to keep track of occupants, the swiping of cards needs to be procedural but not necessary for releasing the door lock or latch. Free egress needs to be available at all times. Another option to free egress is the use of a delayed-egress electrical locking system.

A.7.2.1.6.1.1(3) It is not the intent to require a direct physical or electrical connection between the door release device and the lock. It is the intent to allow door movement initiated by operating the door release device required in 7.2.1.5.10 as one option to initiate the irreversible process.

Several factors need to be considered in approving an increase in delay time from 15 seconds to 30 seconds. Some of the factors include occupancy, occupant density, ceiling height, fire hazards present, fire protection features provided, and the location of the delayed-egress locks. An example of a location where the increase in delay time might not be approved is at an exit stair discharge door.

A.7.2.1.6.1.1(4) In the event that the authority having jurisdiction has permitted increased operation time, the sign should reflect the appropriate time.

A.7.2.1.6.3(14) It is not the intent to prohibit elevator lobby doors from being equipped with card access systems for gaining access, for example, to tenant spaces. It is the sensor-release of electrical locking systems described in 7.2.1.6.2 that is prohibited from being installed on the same door as the lock addressed by 7.2.1.6.3.

See 7.4.2.1.2 and 7.4.2.2.2 for door unlatching requirements for working space about electrical equipment.
The presence of fire exit hardware on a door does not imply the door is required to be a fire protection-rated door.
Examples of doors designed to normally be kept closed include those to a stair enclosure or horizontal exit.
Special-purpose horizontally sliding accordion or folding door assemblies installed in accordance with 7.2.1.14 should not be considered powered doors subject to the provisions of 7.2.1.9.

Powered doors are divided into two categories — power assisted and power operated. Power-assisted doors that conform to ANSI/BHMA A156.19, Power Assist and Low Energy Power Operated Doors, use limited power to operate the door. They require fewer safeguards as compared to full power-operated doors. These door operators are for swinging doors only. Power-operated doors that conform to ANSI/BHMA A156.10, Power Operated Pedestrian Doors, require more power to operate the door and require additional safeguards to provide protection against personal injury. Power-operated doors can be swinging, sliding, or folding doors.

An example of the type of door addressed by 7.2.1.9.1 is one actuated by a motion-sensing device upon the approach of a person.
Although a single power-operated door leaf located within a two-leaf opening might alone not provide more than 30 in. (760 mm) of clear width in the emergency breakout mode, where both leaves are broken out to become side hinged, the required egress width is permitted to be provided by the width of the entire opening.
Security access turnstiles are designed to control security access into and out of buildings. Security access turnstiles might utilize physical barriers consisting of arms, wings, gates, or panels. The subject physical barriers come in various heights and function by retracting or opening in the direction of travel.
Door assemblies within the required means of egress (e.g., door assemblies that discharge from exit enclosures) require a higher level of care and maintenance throughout the life of their installations to ensure they perform as intended by the Code. Annual inspection and functional testing of these door assemblies is necessary to verify that they are maintained in proper working condition. Panic hardware and fire exit hardware devices are specifically required to be used in assembly and educational occupancies. However, door leaves that are equipped with panic hardware or fire exit hardware, in areas not specifically required by the Code (e.g., stairwell entry doors and double-egress cross-corridor door assemblies not serving an assembly occupancy), should be subject to annual inspection and functional testing to ensure that the operating hardware functions correctly in accordance with 7.2.1.7, since the presence of panic hardware and fire exit hardware implies it is required by the Code.

Additionally, door assemblies that are door hardware-release of electrically locked egress door assemblies in accordance with 7.2.1.5.5 and door assemblies that are equipped with special locking arrangements in accordance with 7.2.1.6 are outfitted with electrified hardware and access control devices that are susceptible to wear and abuse. Consequently, these door assemblies need to be inspected and tested on an annual basis, regardless of the occupant load being served.

In cases where the authority having jurisdiction determines there is a distinct hazard to building occupant safety, the inspection requirements of 7.2.1.15 should be applied to other exit access, exit, and exit discharge door assemblies.

See NFPA 80, Annex J, for information pertaining to performance-based inspection, testing, and maintenance of door assemblies.
Performing corrective action work on door assemblies frequently requires ordering replacement components that might take time to produce, ship, and install. Consideration of the time it takes to procure and install components should be included in the timeline for restoring the door assemblies to normal working condition.

A.7.2.2.2.1.1(2) It is the intent of 7.2.2.2.1.1(2) to permit the use of Table 7.2.2.2.1.1(b) in existing buildings, even where there is a change in occupancy per 4.6.11. Safety improvements should be made that are reasonable and feasible at minimal cost. Improvements include removal, repair, or replacement of step coverings, as described in A.7.2.2.3.5, particularly Figure A.7.2.2.3.5(e), and addition of functional handrails and guardrails in place of, or in conjunction with, other rails, as described in 7.2.2.4.

In some cases, the egress capacity provisions of 7.3.3 will require a stair to have a greater width than the minimum specified in 7.2.2.2.1.2.

A.7.2.2.2.1.2(B) The stair width requirement of 7.2.2.2.1.2(B) is based on accumulating the occupant load on each story the stair serves.

The accumulating of occupant load is done for the purposes of the requirements of 7.2.2.2.1.2 only. The egress capacity requirements of Section 7.3 are NOT cumulative on a story-by-story basis.

If additional exits provide egress capacity, the occupant load served by such additional exits, up to the limit permitted for the egress capacity of such additional exits, is not added to the total occupant load considered for the minimum stair width requirements of 7.2.2.2.1.2.

If horizontal exits are provided on any of the stories, the total occupant load of all compartments on the story with the horizontal exits is used in the calculation of the minimum stair width requirements of 7.2.2.2.1.2. The number of stairs permitted through application of horizontal exit requirements in 7.2.4 is not affected by the minimum stair width requirements of 7.2.2.2.1.2.

The examples that follow illustrate applications of the minimum stair width requirement.

A stair in a building two stories in height above grade plane that has 2000 persons on the second story, among 10 equally sized stairs that serve the second story, would be considered to have an occupant load of 200 persons for the purposes of applying Table 7.2.2.2.1.2(B). The minimum width of such a stair would be 44 in. (1120 mm).

For a building with a relatively large floor area, a typical 44 in. (1120 mm) stair would not be required to be increased in width until it serves a building approximately 14 stories in height above grade plane, calculated as follows:

For egress in the descending direction, only the stair width below the 14 stories with the total occupant load of 2000 persons per stair, or 4000 persons if served by two equally sized stairs, would need to be increased to 56 in. (1420 mm). If the building is 20 stories in height above grade plane, only the stairs on the lowest 7 stories would be required to have the 56 in. (1420 mm) width.

For a building 41 stories in height above grade plane with 200 persons on each story (or 8000 persons overall, not including the level of exit discharge), with two equally sized stairs, each stair would be considered to have an occupant load of 4000 persons for the purposes of applying Table 7.2.2.2.1.2(B). Only the portion of the stair serving 2000 persons would be required to have the wider width. If each story provides the same floor area for occupancy, the upper 20 stories would have 44 in. (1120 mm) stairs, and the lowest 20 stories would have the 56 in. (1420 mm) stairs, as a minimum.

If properly designed and constructed, stairs with winders are not necessarily more dangerous than other stairs. Attention to the factors that follow helps to make winders generally more effective for egress and safety. Handrails should be continuous, without breaks at newel posts, from story to story. Handrails located at a greater than normal distance from the inner turn of winders can improve safety by constraining stair users to walk on the portion of the treads providing deeper treads, which should have not less than 11 in. (280 mm) of depth. Combinations of straight flights and winders are best arranged with winders located only below the straight flight. This arrangement is best because the winders provide larger tread dimensions over much of their width than do typical treads on straight flights. A descending person will, thus, be unlikely to experience a reduction of tread depth during descent, a condition of nonuniformity that is best avoided.
The tripping hazard referred to in 7.2.2.3.3.2 occurs especially during descent, where the tread walking surface has projections such as strips of high-friction materials or lips from metal pan stairs that are not completely filled with concrete or other material. In addition, the installation of a retrofit, surface-mounted stair nosing or a strip of high-friction material onto an existing stair tread might produce a projection that creates a tripping hazard. For example, the slight elevation difference between the new stair tread nosing and the stair tread might create enough of an elevation change to trip the stair user. Tread nosings that project over adjacent treads can also be a tripping hazard. ICC/ANSI A117.1, Accessible and Usable Buildings and Facilities, illustrates projecting nosing configurations that minimize the hazard.
"Consistent surface traction" means that slip resistance is reasonably uniform and adequate to minimize risk of slipping across the treads where users' feet contact the tread surface.

For the front-to-back direction, particular attention should be given to consistency of slip resistance in the front two-thirds of the tread, but preferably the entire tread surface. For descent, initial foot contact occurs at the nosing; for ascent, it occurs in the middle of the tread.

For the side-to-side direction, particular attention should be given to consistency of slip resistance within the clear width of the stair between handrails, especially on the portion contacted by users' feet. For most users, this will extend to within about 6 in. (150 mm), measured horizontally, of the handrails; however, some vulnerable stair users might place the front portions of their feet below the handrails.

Consistency is important because misleading user expectation of underfoot conditions is a major factor in missteps and falls involving slipping.

Regarding the slip resistance of treads, it should be recognized that, when walking up or down stairs, a person's foot exerts a smaller horizontal force against treads than is exerted when walking on level floors, including on landings. Therefore, materials used for floors that are acceptable as slip resistant (as described by ASTM F1637, Standard Practice for Safe Walking Surfaces and standards specifically addressing tribology, including ANSI/ASSE A1264.2, Standard for the Provision of Slip Resistance on Walking/Working Surfaces) provide adequate slip resistance where used for stair treads. Such slip resistance includes the important leading edges of treads, the part of the tread that the foot first contacts during descent, which is the most critical direction of travel. If stair treads are wet, there is an increased danger of slipping, just as there is an increased danger of slipping on wet floors of similar materials. A small wash or drainage slope on exterior stair treads is, therefore, recommended to shed water. (See Templer, J. A., The Staircase: Studies of Hazards, Falls, and Safer Design, Cambridge, MA: MIT Press, 1992.)

A small drainage slope for stair treads subject to wetting can improve tread slip resistance (see also A.7.2.2.3.3.2). A consistent slope to a side of the stair, where drainage is possible, might be preferable to a front-to-back slope of the treads. Providing a pitch of 1/8 in./ft to 1/4 in./ft (10 mm/m to 21 mm/m) aids the shedding of water from a nominally horizontal surface.
Figure A.7.2.2.3.5(a), Figure A.7.2.2.3.5(b), Figure A.7.2.2.3.5(c), and Figure A.7.2.2.3.5(d) illustrate the method for measuring riser height and tread depth. Stairs that are covered with resilient floor coverings might need additional tread depth beyond the minimum specified in the Code. Any horizontal projection of resilient covering materials beyond the tread nosing and riser, such as carpet and underlayment, can interfere with users' feet and thereby reduce usable tread depth. At the tread nosing, such resilient covering materials might not be capable of providing stable support for users' feet. Generally, effective tread depth is reduced by the uncompressed thickness of such resilient coverings, and might be further reduced over time if coverings are not well secured, and, consequently, might move forward at the nosings. [See Figure A.7.2.2.3.5(e).]

FIGURE A.7.2.2.3.5(a) Riser Measurement with Tread Slope to Front.

FIGURE A.7.2.2.3.5(b) Riser Measurement with Tread Slope to Back.

FIGURE A.7.2.2.3.5(c) Tread Depth.

FIGURE A.7.2.2.3.5(d) Tread Measurement with Stable Support at Leading Edge.

FIGURE A.7.2.2.3.5(e) Tread Measurement with Unstable Stepping Surface at Leading Edge.

A relatively common error in much of home stair construction and, more rarely, in other stair construction is a failure to make the landing nosing projection consistent with the projection of all other nosings in the stair flight. Such an error can easily occur if the stair flight is installed as a prefabricated unit where the top landing does not have a comparable nosing and the unit includes nosing projections. This heightens the risk of an overstepping misstep, at the second or third step down, by a person who is descending.

A fairly reliable test of step dimension uniformity is the crouch and sight test, in which the inspector crouches on the landing above a flight of stairs to confirm that all of the nosings, including the landing nosing, line up. Unless there is a rare matched variation in the height of a step riser and in the tread depth, both proportionally larger or smaller than other steps in the flight, such that the internosing slope or pitch is maintained consistent in the flight, the visual alignment of the nosings in the crouch and sight test will indicate dimensional uniformity. Thus, as a first task in any stair inspection, the crouch and sight test should be routinely performed. If the stair does not pass this visual test, careful measurements performed in accordance with 7.2.2.3.5 are essential. If the stair appears to pass this test, indicating that the internosing slope or pitch is consistent, a prudent second, quick test is to measure the internosing distances for each step to confirm their consistency.

Step dimensions or their uniformity should not be measured by simply laying a measuring tape or stick on the tread or against the riser. Such measurements could be misleading and erroneous relative to the criteria set out in 7.2.2.3.5, particularly if nosing projections are not uniform (as addressed in 7.2.2.3.6.5), if treads slope, or if the slopes vary within a stair flight.

"Safety yellow" is the widely used, standard color (described in ANSI/NEMA Z535.1, Standard for Safety Colors) to be used for a "caution" function, as a solid color or in alternating, angled yellow-black bars or other geometric combination that draws attention beyond merely designating a nosing. Other nosings, not located above nonuniform risers, need only contrast with the remainder of the step and can be of any color providing contrast relative to the remainder of the tread. Note that similar specification of distinctive and contrasting nosing markings is called for in assembly seating aisle stairs (see, respectively, 12.2.5.6.6(7) and 12.2.5.6.10.1). The safety problems of exterior stairs in assembly aisles and adjacent to a sloping public way are similar, as each individual step has to be visually detected in a reliable fashion. In addition, the presence and location of steps with unavoidably nonuniform risers must be effectively communicated, especially when viewed in the descent direction. Widely varying light conditions further heighten the need for such markings.
The intent of this provision is to place handrails for the required egress width only, regardless of the actual width. The required egress width is provided along the natural path of travel to and from the building. Examples of this requirement are shown in Figure A.7.2.2.4.1.4. The reduced intermediate handrail spacing of 60 in. (1525 mm), along with a handrail height within the permissible height limits, allows users to reach and grasp one handrail. Except as noted in 7.2.2.4.2 and 7.2.2.4.4, handrails are not required on stair landings.

FIGURE A.7.2.2.4.1.4 Assumed Natural Paths of Travel on Monumental Stairs with Various Handrail Locations.

Figure A.7.2.2.4.5 illustrates some of the requirements of 7.2.2.4.4.

FIGURE A.7.2.2.4.5 Handrail Details

Additional handrails, beyond those required by the Code, are permitted at heights other than those stipulated. For example, where children under the age of five are major users of a facility, an additional handrail at a height in the range of 28 in. to 32 in. (710 mm to 810 mm) might be useful. Generally, children prefer to use, and can effectively use, handrails that are located at shoulder to head height due to their developmental characteristics and their less developed balance and walking abilities. At age 3, head height ranges from 35 in. to 40 in. (890 mm to 1015 mm); shoulder height averages 29 in. (735 mm). At age 5, head height ranges from 39 in. to 46 in. (990 mm to 1170 mm); shoulder height ranges from 31 in. to 37 in. (785 mm to 940 mm).

A.7.2.2.4.5.6(2) Handrails should be designed so they can be grasped firmly with a comfortable grip and so the hand can be slid along the rail without encountering obstructions. The profile of the rail should comfortably match the hand grips. For example, a round profile, such as is provided by the simplest round tubing or pipe having an outside diameter of 11/2 in. to 2 in. (38 mm to 51 mm), provides good graspability for adults. Factors such as the use of a handrail by small children and the wall-fixing details should be taken into account in assessing handrail graspability. The most functional, as well as the most preferred, handrail shape and size is circular with a 11/2 in. (38 mm) outside diameter (according to research conducted using adults). Handrails used predominantly by children should be designed at the lower end of the permitted dimensional range.

Handrails are one of the most important components of a stair; therefore, design excesses such as oversized wood handrail sections should be avoided, unless there is a readily perceived and easily grasped handhold provided. In handrail design, it is useful to remember at all times the effectiveness of a simple round profile that allows some locking action by fingers as they curl around and under the handrail.

Perimeter dimension, referred to in 7.2.2.4.5.6(2), is the length of the shortest loop that wraps completely around the railing.

A.7.2.2.4.6.2(3) This reduction in required height applies only to the stair, not to the landings.

Vertical intermediate rails are preferred to reduce climbability.
The purpose of this provision is to protect the exterior wall of a stairway from fires in other portions of the building. If the exterior wall of the stair is flush with the building exterior wall, the fire would need to travel around 180 degrees in order to impact the stair. This has not been a problem in existing buildings, so no protection is required. However, if the angle of exposure is less than 180 degrees, protection of either the stair wall or building wall is required.

Figure A.7.2.2.5.2(a), Figure A.7.2.2.5.2(b), and Figure A.7.2.2.5.2 (c) illustrate the requirement, assuming nonrated glass on the exterior wall of the stair is used.

FIGURE A.7.2.2.5.2(a) Stairway with Nonrated Exterior Wall in Same Plane as Building Exterior Wall.

FIGURE A.7.2.2.5.2(b) Stairway with Unprotected Exterior Perimeter Protruding Past Building Exterior Wall.

FIGURE A.7.2.2.5.2(c) Stairway with Nonrated Exterior Wall Exposed by Adjacent Exterior Wall of Building.

An example of a use with the potential to interfere with egress is storage.
Figure A.7.2.2.5.4 shows an example of a stairway marking sign.

FIGURE A.7.2.2.5.4 Example of a Stairway Marking Sign.

A.7.2.2.5.4.1(M) It is not the intent to require a sign that reads ROOF ACCESS, as such message might be misinterpreted by building occupants as an alternative egress route. However signs that read ROOF ACCESS are not prohibited, as many such signs have been installed in existing buildings so as to make a requirement for removal impractical. Historically, the ROOF ACCESS sign has provided information for the fire department. Where there is no roof access, such information will be posted via a NO ROOF ACCESS sign. The absence of the NO ROOF ACCESS sign should be understood by the fire department to mean that roof access is possible.

Where environmental conditions (such as illumination levels and directionality or a complex visual field that draws a person's attention away from stair treads) lead to a hazardous reduction in one's ability to perceive stair treads, they should be made of a material that allows ready discrimination of the number and position of treads. In all cases, the leading edges of all treads should be readily visible during both ascent and descent. A major factor in injury-producing stair accidents, and in the ability to use stairs efficiently in conditions such as egress, is the clarity of the stair treads as separate stepping surfaces.

For stair nosing marking, surface-applied material, such as adhesive-backed tape and magnetic strips, should not be used, as it is not durable under the scuffing from users' feet and, in coming loose, it creates a tripping hazard. While a carefully applied and consistently maintained coating is acceptable, contrasting color or photoluminescent material integral with the nosings is preferable because of its permanence. It is also the intent of 7.2.2.5.4.3 to require the contrasting stairway tread marking to be a material integral with the stair tread and not a material integral with a stair nosing product that is installed on the stair tread. See also 7.1.6.4 and 7.2.2.3.6 for slip resistance uniformity requirements, as well as prohibition of projections on the treads.

Guidance on the use of photoluminescent marking is provided by ASTM E2030, Standard Guide for Recommended Uses of Photoluminescent (Phosphorescent) Safety Markings. Additional marking, for example, at the side boundaries of the stair, should be applied in accordance with the guidance provided therein.

Coatings and other applied markings, if used, should be durable for the expected usage, especially at end terminations of the marking and at changes in stair direction where usage is more extensive and hand forces are larger.
Exit stair treads are required to incorporate a marking stripe that is applied as a paint/coating or be a material that is integral with the nosing of each step. It is the intent of this provision to require the contrasting stairway tread marking to be a material integral with the stair tread and not a material integral with a stair nosing product that is installed on the stair tread. See also 7.1.6.4 and 7.2.2.3.6 for slip resistance requirements, as well as 7.2.2.3.3.2, which prohibits tread projections.
Examples of obstacles addressed by 7.2.2.5.5.5 are standpipes, hose cabinets, and wall projections.

A.7.2.2.5.5.7(B)(1) The marking stripe for door hardware should be of sufficient size to adequately mark the door hardware. This marking could be located behind, immediately adjacent to, or on the door handle or escutcheon.

The guards that are required by 7.1.8 and detailed in 7.2.2.4.5 will usually meet this requirement where the stair is not more than 36 ft (11 m) above the finished ground level. Special architectural treatment, including application of such devices as metal or masonry screens and grilles, will usually be necessary to comply with the intent of this requirement for stairs over 36 ft (11 m) above the finished ground level.
Where outside stairs are not required to be separated from interior portions of the building in accordance with 7.2.2.6.3.1(1) through (5), such stairs are considered exits and not exit access.
See A.7.2.2.3.4.
The design pressure differences required by 7.2.3.9.1 are based on specific gas temperatures and ceiling heights. The system is required to be approved, because anticipated conditions might be different from those on which the design pressure differences were calculated and, thus, different design pressure differences might be needed. For additional information on necessary minimum design pressure differences, including calculational techniques, or maximum pressure differences across doors to ensure reasonable operating forces, see NFPA 92.
Control wiring for pressurization systems requiring separation includes wiring from the VFD to the fan unit. Where this wiring is not located in the same fire resistance-rated room, protection of this wiring is needed to ensure proper fan operation.
An example of one way to provide the required egress capacity from the upper floor of a department store building measuring 350 ft × 200 ft (107 m × 61 m), with an occupant load of 1166 per floor, would be to furnish eight 44 in. (1120 mm) stairs. [See Figure A.7.2.4.1.2(a).]

FIGURE A.7.2.4.1.2(a) Eight Exits, Required to Provide Necessary Egress Capacity, with None via Horizontal Exit.

The building is assumed to be divided into two sections by a fire barrier meeting the requirements for a horizontal exit, one 130 ft × 200 ft (40 m × 61 m), and the other 220 ft × 200 ft (67 m × 61 m), with two pairs of 46 in. (1170 mm) double egress doors, with each door providing 44 in. (1120 mm) of clear egress width [see Figure A.7.2.4.1.2(b)]. The smaller section, considered separately, will require the equivalent of three 44 in. (1120 mm) exit stairs, and the larger section will require five such exits. The horizontal exits will serve as one of the three exits required for the smaller section and two of the five exits required for the larger section. Therefore, only two 44 in. (1120 mm) exit stairs from the smaller section and three 44 in. (1120 mm) exit stairs from the larger section will be required if the exits can be arranged to meet the requirements for the 150 ft (46 m) travel distance permitted from any point in a nonsprinklered building. Thus, the total number of exit stairs required for the building will be five, as compared to eight if no horizontal exit had been provided.

FIGURE A.7.2.4.1.2(b) Number of Stairs Reduced by Three Through Use of Two Horizontal Exits; Egress Capacity Not Reduced.

Another option would be the use of two 56 in. (1420 mm) exit stairs from the larger section, which would reduce the total number of stairways required from the floor to four [see Figure A.7.2.4.1.2(c)]. However, if the building were further subdivided by a second fire wall meeting the requirements for a horizontal exit, no further reduction in stairways would be permitted in order to comply with the requirement that horizontal exits provide a maximum of one-half of egress capacity.

FIGURE A.7.2.4.1.2(c) Number of Stairs Further Reduced by Widening Stairs in Larger Compartment, But Not to Less than One-Half the Required Number and Capacity of Exits from That Compartment.

It is not the intent of 7.2.4.1.2 to limit the number of doors in the fire barrier forming the horizontal exit. Where doors other than those serving as horizontal exits are provided, such doors are to be considered as convenience openings that are not credited with satisfying any means of egress requirements.

The continuity requirement of 7.2.4.3.1 does not prohibit the horizontal exit fire barrier from being offset on various floors. Where the floor assembly has a minimum 2-hour fire resistance rating and horizontal exit fire barrier walls are provided on all floors to the finished ground level, the continuity provision might be achieved by a combination of horizontal and vertical assemblies. For requirements regarding the alignment of fire barriers separating buildings of differing construction types, see 8.2.1.3.
Figure A.7.2.4.3.2 depicts an example of the use of the exemption provided by 7.2.4.3.2.

FIGURE A.7.2.4.3.2 Example of Horizontal Exit Termination.

The requirements of 7.2.4.3.5 are meant to apply to the horizontal and vertical portions of the fire barrier forming the horizontal exit.
Fusible link-actuated automatic-closing doors do not qualify for use in horizontal exits under these provisions, because smoke might pass through the opening before there is sufficient heat to release the hold-open device. Such doors are also objectionable because, once closed, they are difficult to open and would inhibit orderly egress.
The guards required by 7.1.8 and detailed in 7.2.2.4.5 for the unenclosed sides of ramps will usually meet this requirement where the ramp is not more than 36 ft (11 m) above the finished ground level. Special architectural treatment, including application of such devices as metal or masonry screens and grilles, will usually be necessary to comply with the intent of the requirements for ramps over 36 ft (11 m) above the finished ground level.
Providing a pitch of 1/8 in./ft to 1/4 in./ft (10 mm/m to 21 mm/m) will aid the shedding of water from a nominally horizontal surface.
An exit passageway serves as a horizontal means of exit travel that is protected from fire in a manner similar to an enclosed interior exit stair. Where it is desired to offset exit stairs in a multistory building, an exit passageway can be used to preserve the continuity of the protected exit by connecting the bottom of one stair to the top of the stair that continues to the street floor. Probably the most important use of an exit passageway is to satisfy the requirement that at least 50 percent of the exit stairs discharge directly outside from multistory buildings (see 7.7.2). Thus, if it is impractical to locate the stair on an exterior wall, an exit passageway can be connected to the bottom of the stair to convey the occupants safely to an outside exit door. In buildings of extremely large area, such as shopping