Building classifications

The National Construction Code (NCC) sets out the minimum technical requirements for new buildings (and new building work in existing buildings) in Australia. In doing so, it groups buildings by their use. These groups are assigned a classification which is then how buildings are referred to throughout the NCC. This information is crucial for all NCC users.

The following is a general representation of the building classifications in the NCC. It is based on a national perspective and does not address any state or territory variations. 

State and territory variations and additions to the NCC are located in the NCC (Schedules 4-11).

Building classifications are referenced in Section A of the Governing Requirements, Part A6 of the NCC.

Building classifications are labelled ‘Class 1’ through to ‘Class 10’. Some classifications also have sub-classifications, referred to by a letter after the number (e.g. Class 1a).

Class 2 to 9 buildings are mostly covered by Volume One, and Class 1 and 10 buildings are mostly covered by Volume Two. Volume Three of the NCC refers to all building classifications.

A building may have parts with different uses. In most cases, each of these parts are classified separately.

A building (or part of a building) may also have more than one use and may be assigned more than one classification.

Class 1 buildings are houses. Typically, they are standalone single dwellings of a domestic or residential nature.

These buildings can also be horizontally attached to other Class 1 buildings. 

When attached they are commonly referred to as duplexes, terrace houses, row houses and town houses. In these situations, they must be separated by a wall with fire-resisting and sound insulation properties.

The Class 1 classification includes 2 sub-classifications: Class 1a and Class 1b.

A Class 1a building is a single dwelling being a detached house; or one of a group of attached dwellings being a town house, row house or the like. 

A Class 1b building is a boarding house, guest house or hostel that has a floor area less than 300 m² and ordinarily has less than 12 people living in it. It can also be 4 or more single dwellings located on one allotment which are used for short-term holiday accommodation.

Class 2 buildings are apartment buildings. They are typically multi-unit residential buildings where people live above and below each other. The NCC describes the space considered as an apartment as a sole-occupancy unit (SOU). 

Class 2 buildings may also be single storey attached dwellings with a common space below. For example, 2 dwellings above a common basement or carpark.

Class 3 applies to residential buildings other than Class 1 or Class 2 buildings, or a Class 4 part of a building. Class 3 buildings are a common place of long term or transient living for a number of unrelated people.

Examples include a boarding house, guest house, hostel or backpackers (that are larger than the limits for a Class 1b building). Class 3 buildings could also include dormitory style accommodation, or workers’ quarters for shearers or fruit pickers.

Class 3 buildings may also be ‘care-type’ facilities such as accommodation buildings for children, the elderly, or people with disability, which are not Class 9 buildings.

A Class 4 part of a building is a sole dwelling or residence within a building of a non-residential nature. An example of a Class 4 part of a building would be a caretaker’s residence in a storage facility. A Class 4 part can only be located in a Class 5 to 9 building.

Class 5 buildings are office buildings used for professional or commercial purposes.

Examples of Class 5 buildings are offices for lawyers, accountants, government agencies and architects.

Class 6 buildings are typically shops, restaurants and cafés. They are a place for the sale of retail goods or the supply of services direct to the public.

Some examples are:

• A dining room, bar, shop or kiosk part of a hotel or motel.
• A hairdresser or barber shop. 
• A public laundry.
• A market or showroom.
• A funeral parlour.
• A shopping centre.

Class 7 buildings are storage-type buildings. The Class 7 classification has 2 sub-classifications: Class 7a and Class 7b.

Class 7a buildings are carparks. 

Class 7b buildings are typically warehouses, storage buildings or buildings for the display of goods (or produce) for wholesale.

A factory is the most common way to describe a Class 8 building. It’s a building in which a process (or handicraft) is carried out for trade, sale, or gain. 

The building can be used for production, assembling, altering, repairing, finishing, packing, or cleaning of goods or produce. It includes buildings such as a mechanic’s workshop. It may also be a building for food processing, such as an abattoir.

Class 9 buildings are buildings of a public nature. The Class 9 classification has three sub-classifications: Class 9a, Class 9b and Class 9c.

Class 9a buildings are generally hospitals, referred to as health-care buildings in the NCC. They are buildings in which occupants or patients undergo medical treatment and may need physical assistance to evacuate in the case of an emergency. This includes a clinic (or day surgery) where the effects of the treatment administered involve patients becoming unconscious or unable to move. This in turn requires supervised medical care (on the premises) for some time after treatment has been administered.

Class 9b buildings are assembly buildings in which people may gather for social, theatrical, political, religious or civil purposes. They include schools, universities, childcare centres, pre-schools, sporting facilities, night clubs, or public transport buildings.

Class 9c buildings are residential care buildings that may contain residents who have various care level needs. They are a place of residence where 10% or more of persons who reside there need physical assistance in conducting their daily activities and to evacuate the building during an emergency. An aged care building, where residents are provided with personal care services, is a Class 9c building.

Class 10 buildings are non-habitable buildings or structures. Class 10 includes three sub-classifications: Class 10a, Class 10b and Class 10c.

Class 10a buildings are non-habitable buildings including sheds, carports, and private garages. 

Class 10b is a structure being a fence, mast, antenna, retaining wall, swimming pool, or the like.

A Class 10c building is a private bushfire shelter. A private bushfire shelter is a structure associated with, but not attached to, a Class 1a building.

As buildings can have mixed uses, they can also have mixed (or multiple) classifications. For example, a building may have a basement carpark (Class 7a) with ground floor retail space (Class 6) and residential apartments (Class 2) and offices above (Class 5).

A building (or a part of a building) may be designed to serve multiple purposes and may have more than one classification. This means that it is permissible for a building to be Class 6/7, or Class 5/6, or whatever is deemed appropriate.

This allows flexibility in how the building might be used. For example, if a building is intended for retail shopping, storage or office space, it may be designed as a Class 5/6/7 building.

At the design stage it may not be clear who the final tenant will be (or how they will be using their tenancy), so as long as the design meets the minimum requirements of all the classifications it could be used for any of the purposes.