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Occupancy Classifications in Codes

One of the most critical steps in applying NFPA 101, Life Safety Code, and other building and fire codes to a space is identifying the correct occupancy classification. The occupancy classification drives the requirements for many different fire and life safety features. These requirements reflect the unique and expected characteristics of the anticipated occupants of that space such as, capability of self-preservation, familiarity with the space, age, and alertness. Improperly classifying a building or space risks over- or under-applying necessary code requirements, resulting in buildings lacking fire and life safety features, or containing additional fire and life safety features that are not required by the Code.

While the majority of the NFPA developed codes and standards use occupancy classifications consistent with the Life Safety Code, including NFPA 5000, Building Construction and Safety Code, other organizations’ codes and standards may differ. This can create challenges for the designer when multiple codes and standards are applicable and enforced in a jurisdiction. Perhaps one of the more common scenarios is when both the International Building Code (IBC) and the Life Safety Code apply. Below is a table comparing the different occupancy classifications between the IBC and NFPA 101/5000. One thing to note is that although some of the occupancies seem to correlate obviously, there may be differences between details within the definitions, such as minimum number of occupants, that could result in a different classification.

NFPA 101 and 5000 Occupancy Classification

IBC Occupancy Classification

Assembly

Assembly

(divided into subcategories A-1, A-2, A-3, A-4, A-5)

Ambulatory Health Care

Business

Educational

Educational

Day Care

Educational or Institutional

Health Care

Institutional

(divided into subcategories I-1, I-2, I-3, and I-4)

Detention and Correctional

Residential Board and Care

Institutional or Residential

One- and Two-Family Dwelling

Residential

(divided into subcategories R-1, R-2, R-3 and R-4)

Lodging or Rooming House

Hotels and Dormitory

Apartment

Mercantile

Mercantile

Business

Business

Industrial

Factory and Industrial

(divided into subcategories F-1 and F-2)

Storage

Storage

(divided into subcategories S-1 and S-2)

No equivalent occupancy classification (see paragraph below for additional information)

High Hazard

(divided into subcategories H-1, H-2, H-3, H-4, and H-5)

No equivalent occupancy classification (see paragraph below for additional information)

Utility and Miscellaneous

 

Ambulatory Health Care

One major difference between the NFPA 101/5000 occupancy classifications and the IBC classifications is the ambulatory health care occupancy classification. It is important to understand what types of facilities we are discussing before we get into how these are classified differently. Ambulatory health care occupancies per the Life Safety Code are those occupancies in which four or more patients are being treated simultaneously and are incapable of self-preservation because of (1) the treatment; (2) anesthesia; or (3) the nature of the injury/illness. Although not a separate occupancy classification, the IBC does have a definition for “Ambulatory Care Facility” which closely resembles the NFPA ambulatory health care occupancy. Per the IBC, these types of facilities would be considered business occupancies. NFPA 101 and 5000 create a distinction between business occupancies and ambulatory health care facilities based on the occupants’ ability of self-preservation. Therefore, these types of facilities would not be considered business occupancies but would be considered ambulatory health care occupancies per NFPA. It is worth mentioning that per NFPA a traditional doctor’s office or an urgent care center where patients are still capable of self-preservation would be considered business occupancies.

Educational and Day Care

NFPA 101 separates day care occupancies from educational occupancies. The NFPA and IBC definitions for educational occupancies are fairly similar. At first glance it may seem like some occupancies that would be classified as educational per the IBC would actually be day care occupancies per NFPA. However, when you look more closely at Chapter 16 and 17 of NFPA 101 you find that occupancies in which the primary purpose is education for children 30 months of age or older must comply with the educational occupancy requirements. It should be noted that prior to the 2021 Edition, the age was 24 months.

While the educational definitions are closely aligned between NFPA and IBC, the major difference is the NFPA occupancy classification of day care. There are two main categories of day cares, those providing services for children and those providing services for adults. Instead of calling these day care occupancies, the IBC would classify child day cares serving children under two and a half years old and adult day cares as institutional occupancies. There is one exception to this. A childcare facility with more than 5 but less than 100 clients two and a half years of age or younger, and located on the level of exit discharge, is classified as an educational occupancy per the IBC.

Institutional

The institutional occupancy group in the IBC consists of four different categories: I-1, I-2, I-3, and I-4. These subcategories are based on anticipated occupant characteristics and there are similar occupancy classifications found in NFPA 101/5000. However, in the NPFA codes and standards these are treated as individual occupancy classifications and not as subcategories of a broader classification. Even with the sub-categories, the occupancy classifications do not always obviously align between NFPA and IBC. The table below summarize how the NFPA occupancy classifications would most likely fall into the IBC institutional subcategories.

 

Closer Look at how NFPA Occupancy Classifications Align with IBC Residential Subcategories

NFPA

IBC

Notes

Day Care

I-4

Depends on number of occupants, age of occupants, and location of occupants in relationship to the level of exit discharge

Educational

Health Care

 

I-2

N/A

Detention and Correctional

I-3

N/A

Residential Board and Care

I-1

Depends on the number of occupants

 

R-3

R-4

When starting with the IBC institutional subclassification determining the NFPA occupancy classification is more straightforward. Remember though, it is important to always verify the actual definitions and minimum number of occupant requirements before selecting the appropriate occupancy classification. The table below shows the potential NFPA occupancy based on the IBC institutional subcategory.

 

IBC

NFPA

I-1

Residential Board and Care

I-2

Health Care

I-3

Detention and Correctional

I-4

Day Care

Residential

The residential occupancy group in the IBC consists of four different categories: R-1, R-2, R-3, and R-4. These subcategories are based on anticipated occupant characteristics and there are similar occupancy classifications found in NFPA 101/5000. However, in the NPFA codes and standards these are treated as individual occupancy classifications and not as subcategories of a broader classification. Even with the sub-categories, the occupancy classifications do not always obviously align between NFPA and IBC. The table below summarize how the NFPA occupancy classifications would most likely fall into the IBC residential subcategories.

 

Closer Look at how NFPA Occupancy Classifications Align with IBC Residential Subcategories

NFPA

IBC

Notes

One- and Two-Family Dwelling

R-3

N/A

Lodging or Rooming House

R-1

Depends on the number of occupants

R-3

Hotels

R-1

Depends on the nature of the occupants (transient or not)

R-2

Dormitories

R-2

N/A

Apartment

R-2

N/A

Residential Board and Care

R-3

Depends on the number of occupants

 

R-4

Institutional

If you are starting with the IBC residential subclassification and trying to determine the NFPA occupancy classification, it is not as straightforward. The IBC uses terminology not found in NFPA 101 or 5000 and creates the subclassification groups based on different characteristics of how the space is being used, such as the number of occupants. The table below shows how many potential NFPA occupancies you could have per each IBC residential subcategory.

 

Closer Look at how IBC Residential Subcategories Align with NFPA Occupancy Classifications

IBC

NFPA

Notes

R-1

Lodging or Rooming House

Depends on the number of occupants

Hotel

R-2

Apartment

Depends on the nature of the occupants (transient or not)

Hotels

Dormitories

R-3

One- and Two- Family Dwelling

Depends on (1) number of occupants and/or outsiders and (2) if residents are receiving personal care services

Lodging or Rooming House

Residential Board and Care

R-4

Residential Board and Care

N/A


High Hazard

One of the major differences between how NFPA 101/5000 and the IBC address occupancy classification is how they handle areas and spaces where high hazard materials are present. The IBC has a separate occupancy classification for areas or spaces that manufacture, process, generate, or store “materials that constitute a physical or health hazard” in amounts larger than what is permitted in control areas. NFPA, on the other hand, does not create a separate occupancy classification, instead, there are provisions for high hazard contents that must be followed, regardless of the occupancy whenever applicable. High hazard contents are “those that are likely to burn with extreme rapidity or from which explosions are likely.” Additionally, there are subclassifications of certain occupancies, such as storage and industrial, for those that store or use high-hazard contents. Within the occupancy chapter, additional requirements apply based on the high-hazard classification.

NFPA 5000 has a chapter with additional requirements based on the presence of high hazard contents. Again, this does not change the occupancy classification itself but does require additional fire protection and/or life safety features because of the increased hazard of the space.

Utility and Miscellaneous

Another major difference between how NFPA 101/5000 and the IBC address occupancy classification is the Utility and Miscellaneous occupancy classification the IBC has. There is no equivalent in the NFPA occupancy classification. In the IBC, this group is used for structures such as barns, sheds, and towers. While there is no separate occupancy group for these in the NFPA classifications, these structures would still be assigned an occupancy classification. Depending how the space is actually used, storage, industrial, or business are potential examples of appropriate occupancy classifications. Additionally, NFPA 101 and 5000 have requirements for “Special Construction” and “High-Rise” buildings. Instead of changing the occupancy classification when traditional occupancies are placed in unique buildings or are in unusual surroundings, there are requirements that modify the base occupancy requirements to accommodate for these unusual surroundings or structures and the risks associated with them.

Conclusion

The application of occupancy classifications between different organizations’ codes and standards is not always straight forward. Therefore, when working with multiple codes, you must consider the specific building and the occupant characteristics of that space. Since different occupant thresholds and occupant characteristics are used for different organizations’ codes and standards, you can’t always generalize how the occupancy classifications align. Hopefully, the above tables provided some insight and at least a starting point when trying to determine how the occupancy classifications relate.

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Valerie Ziavras
Technical Services Engineer, supporting product and content development throughout the association.

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