In which type of space would occupant load be calculated using net square footage?

The International Building Code (IBC) specifies whether occupant load is calculated using net or gross floor area. Net floor area is the actual occupied space and does not include ancillary areas like corridors, restrooms, or fixed equipment. According to the IBC, Table 1004.5 "Maximum Floor Area Allowances Per Occupant," both "Exercise rooms" (Assembly A-3) and "Exhibit gallery and museum" spaces (Assembly A-3) require the occupant load to be calculated using the net floor area. This method provides a more accurate count for spaces where the primary function occurs in a defined, usable area.

B. airport terminal: The occupant load for various functions within an airport terminal, such as concourses and waiting areas, is calculated using the gross floor area according to the IBC.

1. International Code Council. (2021). 2021 International Building Code (IBC). Country Club Hills

IL: International Code Council.

Section 1002

Definitions: Defines "FLOOR AREA

NET" as "The actual occupied area not including unoccupied accessory areas such as corridors

stairways

toilet rooms

mechanical rooms and closets."

Table 1004.5

Maximum Floor Area Allowances Per Occupant:

Lists "Exercise rooms" with an occupant load factor of "50 net."

Lists "Exhibit gallery and museum" with an occupant load factor of "30 net."

Lists "Airport terminal" sub-areas (Concourse

Waiting areas

Baggage claim) with factors calculated per "gross" square feet.

2. Piotrowski

C. M. (2016). Professional Practice for Interior Designers (6th ed.). Wiley.

Chapter 13

Codes

Standards

and Regulations: This chapter explains that occupant load calculations are fundamental to life safety and that the IBC tables differentiate between net and gross area. It clarifies that assembly spaces like museums and exercise rooms are typically calculated using net area to reflect the usable space

while areas with less defined functions like airport concourses use gross area. (Specific discussion on occupant load factors).

3. Ballast

D. K. (2017). Interior Design Reference Manual: Everything You Need to Know to Pass the NCIDQ Exam (6th ed.). Professional Publications

Inc.

Chapter 10

Building Codes

Section on Occupant Load: This reference manual

widely used in academic programs preparing for the NCIDQ exam

reproduces and explains the IBC occupant load table. It explicitly states that exercise rooms and museum exhibit areas are calculated based on net floor area

while airport terminals are based on gross floor area.