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Fire Inspection and �Code Enforcement

8th Edition�Inspector II

Chapter 4 — Construction Types and Occupancy Classifications

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�Learning Objective 1

Identify multiple-use occupancies.

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Multi-use occupancies are more complicated to classify.

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Which parts of the facility fall under which occupancy

Determinations required

Examine occupancy certificates or inspection reports
Verify which occupancy classifications have been assigned
In most cases, only need to verify that the structure still falls under the same classification
If a change is found, consult the building official

During inspection

(Cont.)

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Multi-use occupancies are more complicated to classify.

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In general, NFPA®101® does not require the separation of occupancies in the same structure
Local codes may require separations

Code requirements

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Two situations are of particular importance to inspectors.

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Different uses in distinctly different portions of the building

Different uses in an intermingled manner that make it impractical to separate for different classifications

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Intermingled use represents a significant challenge for inspectors.

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NFPA® 101®

Recommends most restrictive requirements
All requirements for one type of occupancy may take precedence
Various requirements from each of the two occupancies may be used

ICC®

Does not have a separate occupancy classification for multiple-use occupancies
Recognizes structures may have two or more occupancy types

Canada

Canadian codes require separations between these occupancies in most instances
Restrict combinations of occupancies when a high-hazard occupancy is involved

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Inspectors need to understand the concept of incidental use.

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Any area designated as incidental use must conform to the occupancy requirements of the building or portion of the building it occupies
Fire separation walls, assemblies, or protection must conform to the requirements for the primary use group

ICC®

Furnace rooms
Parking garages
Incinerator rooms
Labs/Shops
Waste and linen collection rooms over 100 square feet (9.3m²)

Incidental use occupancies

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Model codes usually require fire-resistance-rated separations regarding incidental use.

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System without a fire barrier can be installed where permitted
Construction features must separate the rest of the building from the incidental-use area
Must be capable of restricting the passage of fire

Automatic fire extinguishing system

(Cont.)

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Model codes usually require fire-resistance-rated separations regarding incidental use.

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Must extend from the floor of the use area to the bottom of a fire-resistance-rated floor or ceiling above
Doors leading into these areas must be self-closing or the automatic-closing type that closes when the fire alarm is activated
Doors leading to the areas must meet the provisions outlined in NFPA®80, Standard for Fire Doors and Other Opening Protectives

Partitions

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Structures containing multiple occupancy types are considered to be mixed-use occupancies.

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Each structure is individually classified by its primary occupancy classification

Separated from the other occupancies by the appropriate fire wall separation

Automatic fire suppression system may reduce the fire-resistance rating requirements

Some occupancy classifications are not permitted to share the same building, regardless of fire protection features

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ICC® further divides mixed occupancies.

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Accessory

Nonseparated

Separated

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Know the characteristics of accessory structures.

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Subsidiary to the main occupancy of a structure

Does not include accessory assembly occupancies that are less than 750 square feet (70 m²) that remain as part of the main occupancy classification

Limited to no more than 10 percent of the area of the story on which they are located

Except when applying the code’s assembly occupancy requirements like cafeterias attached to schools

Assembly areas that are accessory to ICC® Group E Educational Occupancies are not considered separate

(Cont.)

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Know the characteristics of accessory structures.

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Group H High-Hazard Groups H-2, H-3, H-4, or H-5 Occupancies must be separated from all other occupancies

Other occupancy types do not require separation except for particular requirements of the individual classification

A storage area accessory to an office building
An office area accessory to a manufacturing area
A sales area accessory to a storage area

Examples of accessory uses

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Know the characteristics of nonseparated occupancies.

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Buildings or portions of buildings that have two or more occupancy uses

Each classified according to its own use

ICC® provisions regarding high-rises and fire protection systems are applied to the entire structure

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Know the characteristics of separated occupancies.

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Entire structures or portions of structures that have several occupancy types contained within them

Adopted fire code restrictions are applied separately, not to the structure as a whole

Each occupancy complies with adopted fire code requirements for its occupancy type

Separation between each of these occupancies is defined in the ICC® codes

(Cont.)

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Know the characteristics of separated occupancies.

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REVIEW QUESTION

What are the different types of multiple-use occupancies?

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�Summary

An inspector’s ability to determine the construction type and occupancy classification of a structure is a critical part of an inspection.
The appropriate occupancy classification must be assigned during the plans review process and verified when the certificate of occupancy is issued before the owner/occupant takes possession of the structure.

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(Cont.)

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�Summary

Model building and fire codes provide the inspector with the guidelines for ensuring that life safety requirements are met.

Because the information in this chapter is general in nature, inspectors must become familiar with their locally adopted codes.

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