Building Codes and Barrier-Free Design 263
mining the occupancy classification is an essential part of the code process. The concept behind occu-
pancy classification is that certain building uses are more hazardous than others. For example, a large
theater with hundreds of people is more dangerous than a single-family residence.
Code publications divide their occupancies into different categories, based on the activities occur-
ring in the space, the associated level of hazards present, and the anticipated number of people occu-
pying the space at any given time. Buildings that house more than one use, will result in more than one
occupancy group being designated for the building. For example if an office building has underground
parking, each occupancy must be considered separately because of the different kinds and degrees of
hazards.
Ten of the most common occupancy classifications used by model codes are:
- Assembly: With certain exceptions, it consists of structures, buildings or portions of that are used
for the gatherings for purposes such as civic, social, religious, recreational functions, the consump-
tion of food or drink, or waiting areas. - Business: Consists of office, professional or service-type transactions.
- Educational: Structures that are used for educational purposes by 6 or more persons over 2 ½
years of age through the 12th Grade. - Factory and Industrial: Structures used for assembling, dissembling, fabricating, finishing, manu-
facturing, packaging, repair or processing operations not classified as Group H or Group S. - Hazardous: With noted exceptions these are structures that are used for manufacturing, process-
ing, generation or storage of materials in quantities that are a physical or health hazard. - Institutional: Used for the care or supervision of people having physical limitations due to health or
age are harbored for medical treatment or other care or treatment or in which occupants are de-
tained for penal or correctional purposes or where the liberty of the occupants are restricted. - Mercantile: Buildings that are utilized for the display and sale of merchandise involving stocks of
goods accessible to the public - Residential: Used for sleeping purposes not classified as Group I or per the IRC (International Res-
idential Code).
R-1 - Multi-unit transient
R-2 - Multi-unit non transient
R-3 - Not classified elsewhere
R-4 - Residential care - Storage Group: Used for storage not classified as hazardous occupancy and consists of:
S-1 - Moderate hazard storage
S-2 - Low hazard storage - Utility and Miscellaneous: Consists of accessory and miscellaneous structures not classified in
other occupancies.
Classification by Construction Type.
Construction type indicates the fire resistance of certain building elements such as fire and party walls,
stair and elevator enclosures, exterior and interior bearing and nonbearing walls, columns, shaft enclo-