REPORT

Building occupancy classes

Department of Building Inspection

Homeowner quick reference

Single family homes, duplexes, and townhomes are occupancy class R-3. Buildings with more than two dwelling units are occupancy class R-2.

A-1 Assembly

Theaters more than 750 square feet with fixed seating for more than 49 people, including:

  • Movie theaters
  • Symphony and concert halls
  • TV studios with live audiences

If the space holds fewer than 50 people, the space is considered Group B Business.

A-2 Assembly

Spaces of more than 750 square feet or more than 49 people consuming food and drink, including:

  • Restaurants and their commercial kitchens
  • Bars and taverns
  • Banquet halls
  • Nightclubs

If the space holds fewer than 50 people or is less than 750 square feet, the space is considered Group B Business.

A-3 Assembly

Spaces more than 750 square feet or that hold more than 49 people for worship, recreation, and amusement, including:

  • Places of religious worship
  • Dance halls without food or drink
  • Gyms and pools without spectator seating
  • Art galleries
  • Libraries
  • Museums
  • Lecture halls
  • Funeral parlors
  • Waiting areas in transportation terminals

If the space holds fewer than 50 people or is less than 750 square feet, the space is considered Group B Business.

A-4 Assembly

Spaces of more than 750 square feet for indoor sporting events that have spectator seating, including:

  • Arenas
  • Skating rinks
  • Swimming pools
  • Tennis courts

A-5 Assembly

Spaces of more than 750 square feet for outdoor sporting events that have spectator or participant seating, including:

  • Bleachers
  • Stadiums
  • Amusement park structures

B Business

Spaces used for offices and professional services including:

  • Banks
  • Barber and beauty shops
  • Professional services, such as architect, attorneys, dentists, and physicians
  • Food processing facilities and commercial kitchens not associated with restaurants
  • Private training centers
  • Print shops
  • Tutoring centers
  • Martial arts studios, gymnastics, and similar training centers
  • Animal hospitals and kennels
  • Ambulatory care for fewer than 7 people
  • Car showrooms

C Camps

Outdoor camps that house attendees for 5 or more days a year.

E Educational

Schools or daycares for more than 6 participants during the day.

F-1 Factory and Industrial

Spaces for assembling, disassembling, manufacturing, processing, or repairing of combustible materials, including:

  • Auto shops
  • Bakeries
  • Breweries or distilleries (more than 16% alcohol content)
  • Construction
  • Laundromat and dry cleaning
  • Print shop

F-2 Factory and Industrial

Spaces for assembling, disassembling, manufacturing, processing, or repairing noncombustible materials (low fire hazard) including:

  • Beverage-making under 17% alcohol content
  • Ceramics
  • Glass products
  • Metal products
  • Ice

H-1 High Hazard

Spaces for storing materials that could detonate, including:

  • Explosives
  • Organic peroxides, detonable
  • Oxidizers, Class 4
  • Unstable reactive materials, Class 3 detonable and Class 4

H-2 High Hazard

Spaces for storing materials that could burn quickly or poses a deflagration hazard, including:

  • Class I, II, or IIIA flammable/combustible liquids or Class 3 oxidizers in open or closed containers under high pressure
  • Combustible dusts that pose a fire hazard
  • Flammable cryogenic fluids
  • Unstable reactive materials, Class 3 nondetonable
  • Water-reactive materials, Class 3

H-3 High Hazard

Spaces for storing materials that could burn readily or pose a physical hazard, including:

  • Consumer fireworks (Class C, common)
  • Class I, II, or IIIA flammable/combustible liquids or Class 3 oxidizers in closed or pressurized closed containers
  • Combustible fibers that pose a fire hazard
  • Oxidizing cryogenic fluids
  • Flammable solids
  • Unstable reactive materials, Class 2
  • Water-reactive materials, Class 2

H-4 High Hazard

Spaces for storing materials that pose a health hazard, including corrosives, highly toxic and toxic materials. Examples include:

  • Chemical processing
  • Storage tanks
  • Sewage plants
  • Power plants

H-5 High Hazard

Semiconductor fabrication facilities, and other research and development spaces using comparable materials.

I-2 Institutional

In-patient facilities for 24-hour supervised medical care for more than 5 people who are bedridden (non-ambulatory), including:

  • Hospitals
  • Detoxification facilities
  • Convalescent home
  • Nursing homes
  • Psychiatric hospitals

I-2.1 Institutional

In-patient facilities for 24-hour custodial medical care for more than 5 people who are bedridden (non-ambulatory).

I-3 Institutional

Spaces for people under restraint or security, including:

  • Detention centers
  • Jails
  • Courthouse holding facilities
  • Correctional facilities
  • Temporary holding facilities
  • Secure interview rooms

I-4 Institutional

Spaces for custodial day care for more than 6 people, who would need physical help in an emergency.

L Laboratory

Spaces where hazardous materials are used for testing, analysis, teaching, research, or development.

M Mercantile

Public spaces where merchandise is displayed and sold, including:

  • Retail stores
  • Department stores
  • Drug stores
  • Gas stations
  • Sales rooms

R-1 Residential

Spaces where people sleep on a temporary basis, including hotels and motels.

R-2 Residential

Spaces with 3 or more dwelling units where people live on a permanent basis, including:

  • Apartments and condominiums
  • Residential hotels with in-unit kitchens
  • Dormitories with in-unit kitchens

R-2.1 Residential

Assisted living or rehabilitation facilities with 24-hour care services for more than 6 people who are not bedridden, including:

  • Assisted living facilities
  • Residential care facilities
  • Congregate living health facilities
  • Group homes
  • Rehabilitation facilities
  • Community treatment programs
  • Work furlough programs
  • Alcoholism or drug abuse recovery or treatment facilities

R-3 Residential

Spaces where people live on a permanent basis, including one to two-unit dwellings like single family homes, townhomes, and duplexes.

R-3 Residential also include other permanent sleeping units where multiple people can share a kitchen, such as:

  • Dormitories with no kitchen or a shared kitchen
  • Fraternities and sororities with no kitchen or a shared kitchen
  • Monasteries
  • Adult or child day care facilities for fewer than 6 people

R-3.1 Residential

Government facilities providing 24-hour care, with fewer than 6 clients.

R-4 Residential

Spaces for custodial care for between 6 and 16 people, who would not need physical help in an emergency, including assisted living and rehabilitation facilities.

S-1 Storage

Buildings used for storage of combustible materials that are otherwise non-hazardous.

S-2 Storage

Buildings used for storage of noncombustible materials that are otherwise non-hazardous.

U Utility and Miscellaneous

Buildings not classified in any specific occupancy, including:

  • Carports and private garages
  • Retaining walls
  • Fences more than 6 feet tall
  • Agricultural buildings and features (barns, tanks, towers, stables, livestock shelters)
  • Sheds
  • Communication equipment structures less than 1500 square feet