Building Classifications and Classes Guide (BCA) in Australia

Jul 21, 2023

Exploring Building Classifications under the National Construction Code - Building Code of Australia

When it comes to constructing buildings in Australia, understanding the different classifications is crucial. The National Construction Code (NCC) - Building Code of Australia (BCA) provides guidelines and standards for the construction industry. In this blog post, we'll delve into the various building classifications defined in the NCC-BCA, helping you gain a comprehensive understanding of their significance and requirements.

Class 1: Dwellings

Class 1 buildings are primarily used for residential purposes. This classification includes detached houses, townhouses, and units. Class 1 buildings are designed to be occupied by a single household and have their own private facilities. These buildings typically have minimal shared spaces and limited occupancy.


Class 1a building - is a single dwelling that is a detached house; or one of a group of attached dwellings such as townhouses.


Class 1b building - is a building that has a floor area less than 300 m2, and usually has less than 12 people living in it. Examples include boarding houses, hostels or student houses

Class 2: Apartments

Class 2 buildings include apartment blocks and are typically multi-unit residential buildings where people live above and below each other. These buildings are intended to house multiple households and may have shared facilities such as corridors, stairwells, and lifts. Class 2 buildings require careful consideration of fire safety measures, acoustic insulation, and other factors related to multiple occupancy.

Class 3: Hotels and Commercial Accomodation

Class 3 buildings encompass hotels, motels, dormitories, and other types of commercial accommodations. These structures are designed for short-term accommodation purposes and cater to the general public. Class 3 buildings must adhere to strict safety standards, accessibility requirements, and regulations regarding amenities and services.

Class 4: Caretaker's Residence

A Class 4 building is a dwelling or residence within a building of a non-residential nature. To be considered a Class 4 building, it must be the only dwelling within a Class 5, 6, 7, 8 or 9 building. The most common include a caretaker’s flat within a building; and accommodation over or otherwise connected to a shop. Class 4 buildings must meet specific requirements related to fire safety and accessibility due to their connection with a higher-risk, commercial building.

Class 5: Office Buildings

Class 5 buildings are dedicated office spaces and are primarily used for administrative, clerical, or professional purposes. This classification encompasses professional chambers or suites, lawyers’ offices, government offices, advertising agencies and accountants’ offices. Class 5 buildings require increase fire safety, proper ventilation, and adequate access for occupants.

Class 6: Retail and Service Buildings

Class 6 building is a building where goods or services are directly sold or supplied to the public. Examples of a Class 6 building may include —


  • a place where food or drink may be purchased such as a café or restaurant; or
  • a dining room, bar area that is not an assembly building, shop or kiosk part of a hotel or motel; or
  • a hairdresser’s or barber’s shop, public laundry, veterinarian; or
  • supermarket or sale room, florist, showroom, or service station. These structures are intended for the display and sale of goods to the public.


Class 6 buildings must comply with regulations related to fire safety, accessibility, and customer amenities.

Class 7: Carparks & Warehouses

Class 7 includes the following sub-classifications:


  1. Class 7a — a carpark but is neither a private garage nor used for the servicing of vehicles, other than washing, cleaning or polishing.
  2. Class 7b — a building that is used for storage, or display of goods or produce for sale by wholesale (warehouse).


These buildings can be standalone or part of a larger development and are subject to regulations related to fire safety, ventilation, and circulation.

Class 8: Factories and Laboratories

Class 8 buildings are industrial in nature and include factories, laboratories, and manufacturing plants. These structures are primarily used for production, assembling, altering, repairing, packing, finishing, or cleaning of goods or produce for sale takes place. Class 8 buildings must meet stringent requirements for fire safety, ventilation and structural stability.

Class 9: Public Assembly Buildings

Class 9 buildings are public assembly spaces, including theaters, cinemas, auditoriums, sports stadiums, and convention centers. These structures accommodate large groups of people for entertainment, cultural, or sporting events. Class 9 buildings have specific regulations for crowd management, emergency exits, fire safety, and accessibility.


Class 9 includes the following sub-classifications:


  1. Class 9a — a health-care building including any parts of the building set aside as laboratories, and includes a health-care building used as a residential care building.
  2. Class 9b — an assembly building These buildings can include —
  3. theatres, cinemas and halls, churches, schools, early childhood centres, kindergartens, preschools and childminding centres; and
  4. indoor cricket, tennis, basketball centres and sport stadiums; and
  5. nightclubs, discotheques, bar areas providing live entertainment and/or containing a dance floor, public halls, dance halls and other places of entertainment; and
  6. snooker halls; and
  7. bus and railway stations
  8. Class 9c — a residential care building that may contain residents who have various care level needs, such as aged care.

Class 10: Non-habitable buildings or structures

A Class 10 includes the following sub-classifications:


  1. Class 10a is a non-habitable building including a private garage, carport, shed or the like.
  2. Class 10b is a structure that is a fence, mast, antenna, retaining wall or free-standing wall or swimming pool or the like.
  3. Class 10c is a private bushfire shelter


Understanding the different building classifications outlined in the NCC - BCA 2022 is crucial for architects, builders, and developers. Compliance with the specific requirements for each class ensures the safety, functionality, and suitability of the constructed buildings. It is essential to consult

the relevant codes and seek professional advice to ensure compliance with the regulations specific to each classification.

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