One of, if not the most important aspect, to a building or part thereof is defining it’s classification, or better put, the buildings Major Occupancy Classification. A buildings Major Occupancy Classification plays a crucial role in determining many different key items pertaining to the building’s Fire Protection, Occupant Safety and Accessibility. In fact it’s so important that in Part 3 of Division B, “Classification of Buildings or Parts of Buildings by Major Occupancy” is one of the very first sections that can be found! After turning to Part 3 of Division B, we are almost immediately presented with 3.1.2. Classification of Buildings or Parts of Buildings by Major Occupancy! So how to determine a building’s Major Occupancy Classification? This quick guide will explain everything you need to know.
Table of Contents
What Exactly is a Building’s Major Occupancy Classification?
Before we fully dive into how to determine a building’s major Occupancy Classification, it’s important to first explain what exactly is a building’s major occupancy classification? As outlined in the building code (for the use of this article we will be using the Ontario Building Code 2024, but the national/ other provincial building codes will follow the same format), Major Occupancy is defined as the following “Major occupancy means the principal occupancy for which a building or part of a building is used or intended to be used, and is deemed to include the subsidiary occupancies that are an integral part of the principal occupancy.“
Now we get it, reviewing the definition that is provided in section 1.4.1.2. Definitions of Words and Phrases from the Ontario Building Code can be slightly confusing. For lack of a better word, building codes use “legalese”, and while the reason behind this is valid, it can get a little bit confusing for us not in the legal world!
So to simply explain what a building’s major occupancy classification is, it is simply the category we put a building into based on what it is used for. That’s it! Think of it as if you were at the grocery store looking for bagels, cheese and tomatoes. Each of these foods would have their own category that they would be classified into. Bagels would be found in the bread section, cheese would be found in the dairy section and tomatoes would be found in the produce section. Buildings work the same way!
What are the Major Occupancies Found in the Building Code?
We briefly mentioned in the introduction, that the major occupancies are first introduced to us in Part 3 of Division B, specifically the list of major occupancies can all be found in 3.1.2. Classification of Buildings or Parts of Buildings by Major Occupancy. Here we are presented with Table 3.1.2.1, this table defines all major occupancies that buildings will be classified under:
| Group | Division | Description of Major Occupancies |
|---|---|---|
| A | 1 | Assembly occupancies intended for the production and viewing of the performing arts |
| A | 2 | Assembly occupancies not elsewhere classified in Group A |
| A | 3 | Assembly occupancies of the arena type |
| A | 4 | Assembly occupancies in which occupants are gathered in the open air |
| B | 1 | Detention occupancies |
| B | 2 | Care and treatment occupancies |
| B | 3 | Care occupancies |
| C | — | Residential occupancies |
| D | — | Business and personal services occupancies |
| E | — | Mercantile occupancies |
| F | 1 | High-hazard industrial occupancies |
| F | 2 | Medium-hazard industrial occupancies |
| F | 3 | Low-hazard industrial occupancies |
As you can see from the table above, there are thirteen categories that a building can be classified into plus one additional category “Group G”, which would be for farm/ agricultural buildings. Now to simplify the different categories further, here is a simpler break down of what each category is used for:
- Group A: Assembly Buildings – Places where people gather for events, like theaters, arenas, and open-air venues.
- Group B: Care or Detention Buildings – Places where people receive care or are detained, like hospitals, nursing homes, and jails.
- Group C: Residential Buildings – Places where people live, like houses and apartment buildings.
- Group D: Business Buildings – Places where people work in offices or provide personal services, like banks or hair salons.
- Group E: Shopping Buildings – Places where people buy things, like stores and shopping malls.
- Group F: Industrial Buildings – Places where things are made or stored, like factories and warehouses.
| Group A: Assembly Buildings | Group B: Care or Detention Buildings | Group C: Residential Buildings |
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| Group D: Business Buildings | Group E: Shopping Buildings | Group F: Industrial Buildings |
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How Does the Building Code Define Each Major Occupancy Classification?
Now the tricky part is, the descriptions in table 3.1.2.1., aren’t that descriptive are they? While they do give a basic overview of what each major occupancy classification is, they do not get into specifics or provide examples.
However fear not! We are provided with two different methods of further defining what each major occupancy classification is and what uses apply to which classification.
#1 – Using the Definitions from Part 1 of Division A
The first method we can use to further define what building type falls into which classification, is to use the terms that are defined in 1.4.1.2. Definitions of Words and Phrases. Each definition is outlined below:
- Assembly occupancy means the occupancy or the use of a building or part of a building by a gathering of persons for civic, political, travel, religious, social, educational, recreational or similar purposes or for the consumption of food or drink.
- Detention occupancy (Group B, Division 1) means an occupancy in which persons are under restraint or are incapable of self-preservation because of security measures not under their control.
- Care and treatment occupancy (Group B, Division 2) means an occupancy in which persons receive special care and treatment.
- Care occupancy (Group B, Division 3) means an occupancy, other than a retirement home, in which special care is provided by a facility, directly through its staff or indirectly through another provider, to residents of the facility.
(a) who require special care because of cognitive or physical limitations, and
(b) who, as a result of those limitations, would be incapable of evacuating the occupancy, if necessary, without the assistance of another person. - Residential occupancy means an occupancy in which sleeping accommodation is provided to residents who are not harboured for the purpose of receiving special care or treatment and are not involuntarily detained and includes an occupancy in which sleeping accommodation is provided to residents of a retirement home.
- Business and personal services occupancy means the occupancy or use of a building or part of a building for the transaction of business or the provision of professional or personal services.
- Mercantile occupancy means the occupancy or use of a building or part of a building for the displaying or selling of retail goods, wares, or merchandise.
- High hazard industrial occupancy (Group F, Division 1) means an industrial occupancy containing sufficient quantities of highly combustible and flammable or explosive materials to constitute a special fire hazard because of their inherent characteristics.
- Medium hazard industrial occupancy (Group F, Division 2) means an industrial occupancy in which the combustible content is more than 50 kg/m² or 1 200 MJ/m² of floor area and that is not classified as a high hazard industrial occupancy.
- Low hazard industrial occupancy (Group F, Division 3) means an industrial occupancy in which the combustible content is not more than 50 kg/m² or 1 200 MJ/m² of floor area.
#2 – Using the Examples Provided Per A-3.1.2.1.(1)
The second method you can use to determine a building’s major occupancy classification is to use the list of examples provided in A-3.1.2.1.(1). This is a fantastic reference that will provide you with several different building types and show you which major building occupancy classification they fall under.
The following download link below will allow you to download our very own PDF “Cheat Sheet”, which you can then save and easily reference!
As well, the list from A-3.1.2.1.(1) has been provided below:
Group A, Division 1
Motion picture theatres
Opera houses
Television studios admitting a viewing audience
Theatres, including experimental theatres
Group A, Division 2
Art galleries
Auditoria
Bowling alleys
Child care facility
Churches and similar places of worship
Clubs, nonresidential
Community halls
Courtrooms
Dance halls
Exhibition halls (other than classified in Group E)
Gymnasia
Lecture halls
Libraries
Licensed beverage establishments
Museums
Passenger stations and depots
Recreational piers
Restaurants
Schools and colleges, nonresidential
Undertaking premises
Group A, Division 3
Arenas
Indoor swimming pools
Rinks
Group A, Division 4
Amusement park structures (not elsewhere classified)
Bleachers
CanadianBuildingCodes.ca – Canadian Building Codes made easy.
Grandstands
Reviewing stands
Stadia
Group B, Division 1
Jails
Penitentiaries
Police stations with detention quarters
Prisons
Psychiatric hospitals with detention quarters
Reformatories with detention quarters
Group B, Division 2
Facilities for people with developmental disabilities
Homes for the aged
Hospitals
Infirmaries
Long term care
Nursing homes
Psychiatric hospitals without detention quarters
Reformatories without detention quarters
Sanatoria without detention quarters
Group B, Division 3 (See also Sentence 3.1.2.5.(1).)
Children’s custodial homes
Convalescent homes
Group homes for people with developmental disabilities
Residential care facilities
Sanatoria without detention quarters
Group C
Apartments
Boarding houses
Camps for housing workers
Clubs, residential
Colleges, residential
Convents
Dormitories
Group homes
Halfway houses, drug and alcohol treatment
Hostels
Hotels
Houses
Lodging houses
Monasteries
Motels
Open and semi-secure detention for youth
Recreational camps
Rooming houses
Shelters for homeless
Shelters for women
Schools, boarding
Group D
Banks
Barber and hairdressing shops
Beauty parlours
Dental offices
Dry cleaning establishments, self-service, not using
flammable or explosive solvents or cleaners
Laundries, self-service
Medical offices
Offices
Police stations without detention quarters
Radio stations
Small tool and appliance rental and service
establishments
Group E
Department stores
Exhibition halls
Markets
Restaurants with an occupant load not more than
30 persons consuming food and drink
Shops
Stores
Supermarkets
Group F, Division 1
Bulk plants for flammable liquids
Bulk storage warehouses for hazardous substances
Cereal mills
Chemical manufacturing or processing plants
Distilleries
Dry cleaning plants using flammable or explosive
solvents or cleaners
Feed mills
Flour mills
Grain elevators
Lacquer factories
Paint, varnish and pyroxylin product factories
Rubber processing plants
Spray painting operations
Group F, Division 2
Aircraft hangars
Cold storage plants
Dry cleaning establishments not using flammable or
explosive solvents or cleaners
Electrical substations
Freight depots
Helicopter landing areas on roofs
Laboratories
Laundries, except self-service
Planing mills
Printing plants
Repair garages
Self-service storage buildings
Service stations
Storage rooms
Television studios not admitting a viewing audience
Tire storage
Warehouses
Woodworking factories
Group F, Division 3
Creameries
Laboratories
Power plants
Storage garages, including open air parking garages
Storage rooms
Warehouses
How to Determine a Building’s Major Occupancy Classification?
So now that we have reviewed both what is a building’s major occupancy classification and what are the major occupancy classifications, it’s now time to dive into how to determine a building’s major occupancy classification.
To determine a building’s major occupancy classification, all you have to do is determine what your building or part of your building is going to be used for, and then simply match to which ever major occupancy best suits your use.
Depending on your building, you will have one of two scenarios:
- Your building has one single use, meaning the entirety of your building is dedicated to only one major occupancy.
- Your building has multiple uses, meaning your building is indented to be used by more than one major occupancy.
#1 – Your Building has One Single Use
If your building only has one single use, then it will simply have only one major occupancy classification.
Here is an example:
The example above is a single storey Restaurant, since the entire building is dedicated to one use, and referencing the the examples/ definitions in the previous section, we can determine that this building would have a major occupancy classification of Group A Division 2 (Assembly Occupancy).
#2 – Your Building has Multiple Uses
If your building has more than one use, then the building will be classified according to all major occupancies for which it is used or intended to be used. Here is an example:
In the example above, the building contains three separate units with three seperate uses. A restaurant, a shoe store and a dental office. Referencing the steps in the previous section, we can determine the occupancy classification for each use:
- Restaurant = Group A Division 2 (Assembly Occupancy).
- Shoe Store = Group E (Mercantile Occupancy).
- Dentist Office Group D (Business and Personal Services Occupancy).
There for the Major Occupancy Classification(s) of this building would be: Group A Division 2, Group E and Group D
Conclusion
That’s it! That’s how simple it is to determine the Major Occupancy Classification of your building! While it may seem daunting at first, so long as you follow the steps above – you’ll be determining the Major Occupancy Classification’s of your building’s in no time.
If you have any questions, please don’t hesitate to leave a comment below or send an email to info@canadianbuildingcodes.ca.
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