This guide provides information on the grouping of buildings as referred to in the NCC.
Keywords: National Construction Code (NCC), building classifications, mixed-use buildings
Target audience: Architects and designers, builders, educators, engineers, plumbers, surveyors, and certifiers
The Building Code of Australia (BCA) is contained within the National Construction Code (NCC) and provides the minimum necessary requirements for safety, health, amenity and sustainability in the design and construction of new buildings (and new building work in existing buildings) throughout Australia.
Building Classifications
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 is classified separately.
A building (or part of a building) may also have more than one use and may be assigned more than one classification.
Did you know: In this document, a building may also refer to a structure such as a swimming pool.
Class 1 Building
Houses or dwellings of a domestic or residential nature—single or horizontally attached to other Class 1 buildings such as terrace houses, row houses, or townhouses.
In these situations, they must be separated by a wall that has fire‑resisting and sound insulation properties. 2 subclasses include:
- class 1a—is a single dwelling being a detached house; or one of a group of attached dwellings being a townhouse, row house or the like.
- class 1b—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 four or more single dwellings located on one allotment which are used for short-term holiday accommodation.
Did you know: Class 1 buildings cannot be located above or below any other dwelling (or any other class of building) other than a private garage.
Class 2 Building
Apartment buildings—residential buildings containing two or more sole-occupancy units (SOU) where people live above, beside or below each other.
Class 2 may also be single-storey attached dwellings where there is a common space below, such as a basement or car park.
What is an SOU?
A sole-occupancy unit (SOU) is defined in the NCC. It’s a part of a building for occupation by an owner/s, lessee, or tenant, to the exclusion of any other owner/s, lessee, or tenant. Put simply, it’s a space with exclusive use in a building.
SOUs can be found in other building classifications. They include a:
- residential apartment or flat
- self-contained unit
- suite of rooms in a hotel or motel
- shop in a shopping centre.
Class 3 Building
A residential building, other than a Class 1 or 2 building, which is a common place of long-term or transient living for a number of unrelated persons, such as:
- boarding-house
- hostel
- backpackers accommodation
- residential part of a hotel, motel, school or detention centre.
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 a disability, and which are not considered to be Class 9 buildings.
Class 4 part of a building
Part of a building that is a dwelling or residence within a non-residential building (Class 5 to 9), such as a caretaker’s residence in a hospital.
Class 5 Building
Office buildings for professional and/or commercial purposes (excluding Class 6 to 9), such as offices for government agencies, accountants or lawyers.
When is a general medical practitioner’s office not a Class 5 building?
Generally, a general medical practitioner’s office will be a Class 5 building.
However, if any medical treatment administered leaves patients unconscious or non-ambulatory, then the building would be considered a health-care building (as defined by the NCC) and therefore a Class 9a building.
Class 6 Building
Shops, restaurants and cafés—places for the sale of retail goods or the supply of services direct to the public, such as:
- dining room, bar, shop or kiosk part of a hotel or motel
- hairdresser or barber shop
- public laundry
- market or showroom
- funeral parlour
- shopping centre.
Is a service station a Class 6 building?
Yes, as they are intended for the servicing of cars and the sale of fuel or other goods.
However, the term ‘service station’ does not cover buildings where panel beating, auto electrical, tyre replacement, or the like are solely carried out. These are Class 8 buildings.
Class 7 Building
Buildings including car parks, warehouses or storage buildings. This class includes two sub-classifications:
- class 7a—carparks
- class 7b—warehouses, storage buildings or buildings for the display of goods (or produce) that is for wholesale.
Did you know: Reference to wholesale means “sale to people in the trades or in the business of ‘on-selling’ goods and services to another party (including the public)”.
Class 8 Building
Factories—buildings used for production, assembling, altering, repairing, finishing, packing, or cleaning of goods or produce.
It includes buildings such as a:
- mechanic’s workshop
- abattoir
- laboratory.
Are farm buildings Class 7, 8, or 10a?
It depends on the occupancy, use, and size. Buildings used for farming-type purposes are often very diverse in nature. For example, a shed for parking a single tractor may be Class 10a; if multiple tractors and other farm machinery are parked, the building may be Class 7a (or even Class 8 if mechanics are employed to regularly work on the machinery within the building).
The NCC defines a difference between a farm shed and a farm building. It also contains specific Deemed-to-Satisfy Provisions for these buildings under Part I3.
Class 9 Building
Public buildings—with three sub-classifications:
- class 9a—healthcare buildings such as hospitals and day surgery clinics
- class 9b—buildings where people assemble for social, political, theatrical, religious or civic purposes, e.g. churches, schools, universities, sports facilities, night clubs
- class 9c—aged care facilities.
Did you know: Laboratories that are part of health-care buildings are classified as Class 9a buildings despite the general classification of laboratories being Class 8.
Class 10 Building
Non-habitable buildings or structures. This class includes three sub-classifications:
- class 10a—non-habitable buildings including sheds, carports, and private garages.
- class 10b— structures such as fences, masts, antennas, retaining walls, swimming pool
- class 10c—private bushfire shelter associated with, but not attached to, a class 1a building.
What is a private garage?
A garage associated with a Class 1 building or
A single storey of a building containing not more than 3 vehicle spaces (limited to only one storey within a building) or
Any separate single-storey garage associated with another building that contains no more than 3 vehicles.
Mixed Use Buildings
As buildings can have mixed uses, they can also have mixed (or multiple) classifications. For example, a building may have a basement car park (Class 7a) with ground-floor retail space (Class 6), residential apartments (Class 2), and offices above (Class 5).
How big must a part of a building be to have its own classification?
Every part of a building must be separately classified. However, where a part has a different purpose and is not more than 10% of the floor area of the storey it is on, subject to some limitations, it may be considered ancillary to the major use and adopt its classification.
For instance, if a single-storey warehouse (Class 7b) has an office (normally Class 5) which takes up only 8% of the floor area, the whole building can be classified as a Class 7b. However, if the office takes up 12% of the floor area, then the warehouse (Class 7b) and office (Class 5) must be classified separately.
Multiple Building Classifications
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.