NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings

G6

Part G6 Occupiable outdoor areas

Part G6 Occupiable outdoor areas

Introduction to this Part

This Part provides additional Deemed-to-Satisfy Provisions for buildings that include an occupiable outdoor area.

Objectives, Functional Statements and Performance Requirements

The Objectives and Functional Statements for Part G6 are contained in Sections C, D, E, F and G of this Guide. The Performance Requirements for Part G6 are contained in Sections C, D, E, F and G. Part G6 contains Deemed-to-Satisfy Provisions for occupiable outdoor areas in addition to those contained in Sections C, D, E, F and G.

A number of the Deemed-to-Satisfy Provisions in Part G6 qualify the application of the corresponding Deemed-to-Satisfy Provisions contained in Sections C, D, E, F and G which are considered necessary for occupiable outdoor areas.

Specific comments regarding Specification 5C1.1 (fire-resisting construction provisions) and Specification 20E2.2a (smoke hazard management provisions) are found in those sections of this Guide.

Deemed-to-Satisfy Provisions

(1) The Deemed-to-Satisfy Provisions of this Part apply to buildings containing an occupiable outdoor area in addition to the other Deemed-to-Satisfy Provisions of NCC Volume One.

(2) The Deemed-to-Satisfy Provisions of this Part take precedence where there is a difference to the Deemed-to-Satisfy Provisions of Sections C, D, E, F and G.

(3) Except for G6D2, the Deemed-to-Satisfy Provisions of this Part do not apply to—

  1. an occupiable outdoor area of a sole-occupancy unit in a Class 2 or 3 building, Class 9c building or Class 4 part of a building; or
  2. an occupiable outdoor area with an area less than 10m2.

Explanatory information

Part G6 contains Deemed-to-Satisfy Provisions additional to those contained in Sections C, D, E, F and G for occupiable outdoor areas.

To clarify that Part G6 applies only to buildings containing an occupiable outdoor area and its provisions override Sections C, D, E, F and G of the BCA if there is a difference.

G6D1(1) indicates that the Deemed-to-Satisfy Provisions of Part G6 apply to buildings containing an occupiable outdoor area. These provisions are additional to other Deemed-to-Satisfy Provisions of the BCA that apply to occupiable outdoor areas, for example the relevant provisions of Part D4 relating to access for people with a disability.

G6D1(2) provides a rule for resolving inconsistencies between the requirements in Part G6 and those in the remainder of the BCA, by providing that the Deemed-to-Satisfy Provisions of Part G6 take precedence where there is a difference.

G6D2(3) requires that certain provisions are not applied to private residential balconies or smaller balconies found in commercial buildings.

(1) Subject to (2), a lining, material or assembly in an occupiable outdoor area must comply with C2D11 as for an internal element.

(2) The following fire hazard properties of a lining, material or assembly in an occupiable outdoor area are not required to comply with C2D11:

  1. Average specific extinction area.
  2. Smoke-Developed Index.
  3. Smoke development rate.
  4. Smoke growth rate index (SMOGRARC).

To specify fire hazard property requirements for an occupiable outdoor area.

G6D2 is included to ensure that materials and assemblies in occupiable outdoor areas restrict the spread of fire and heat to maintain tenability to permit egress. As a result, the fire hazard properties relating to flammability and flame propagation apply to occupiable outdoor spaces.

A concession has been applied to the smoke hazard management requirements of C2D11 because occupiable outdoor spaces, being unenclosed, are unlikely to be affected by a build-up of smoke.

For the purposes of the Deemed-to-Satisfy Provisions of C3D8, C3D9 and C3D10, a reference to a storey includes an occupiable outdoor area, however a fire wall cannot be used to separate an occupiable outdoor area into different fire compartments.

To specify fire-resistance and separation requirements for an occupiable outdoor area.

An occupiable outdoor area may have a different classification to other parts of the building located alongside it or on an adjacent level. Further, an occupiable outdoor area may be fire-separated from other parts of a building. G6D3 therefore applies the requirements of C3D8, C3D9 and C3D10 to occupiable outdoor areas.

For the purposes of the Deemed-to-Satisfy Provisions of Part D2, a reference to a storey or room includes an occupiable outdoor area.

To specify requirements to allow occupants to escape from an occupiable outdoor area in the event of an emergency.

G6D4 is included to ensure that requirements which allow occupants to escape are applied to occupiable outdoor areas as for an internal, occupied part of the building. G6D4 in addition clarifies that a reference to a storey or room includes an occupiable outdoor area. This may require the inclusion of a fire-isolated exit stair for a building that would otherwise not require one if it did not have a rooftop occupiable outdoor area.

This is in recognition that occupants of an occupiable outdoor area are constrained by the building, and therefore require a means of evacuation in an emergency.

Consequently, the provisions from Part D2 as applied under G6D4 are considered the minimum necessary to enable safe egress.

For the purposes of the Deemed-to-Satisfy Provisions of Part D3, a reference to a storey or room includes an occupiable outdoor area.

To specify requirements for the construction of exits in an occupiable outdoor area.

G6D5 is included to ensure that requirements for the construction of exits are applied to an occupiable outdoor area and clarifies that a reference to a storey or room (for example, as found in D3D26(4)) includes an occupiable outdoor area.

Except for S17C7(2)(a), for the purposes of the Deemed-to-Satisfy Provisions of Part E1, a reference to a storey includes an occupiable outdoor area.

Notes

An occupiable outdoor area is not a storey for the purposes of Schedule 2 of the NCC and therefore is not included in the determination of rise in storeys.

To specify requirements for fire fighting equipment in an occupiable outdoor area.

G6D6 outlines the appropriate requirements for fire fighting equipment for an occupiable outdoor area and clarifies that a reference to a storey includes an occupiable outdoor area. This is in recognition that an occupiable outdoor area is considered to represent a level of hazard that justifies the installation of fire fighting equipment.

G6D6 contains an exclusion for S17C7(2)(a) to enable a building containing an occupiable outdoor area at its roof level to have a storage tank for a sprinkler system located in the level below.

For the purposes of the Deemed-to-Satisfy Provisions of Part E3, a reference to a storey includes an occupiable outdoor area.

To specify requirements for lift installations in an occupiable outdoor area.

G6D7 outlines that an occupiable outdoor area is considered as a storey for the purposes of Part E3.

This requirement ensures, among other things, that where an emergency lift is installed it serves an occupiable outdoor area.

For the purposes of the Deemed-to-Satisfy Provisions of Part E4, a reference to a storey includes an occupiable outdoor area.

To specify requirements to minimise the risk of death or injury to occupants during an emergency because of
• an inability to see their way along an exit path of travel
• an inability to find an exit; and
• a lack of knowledge that an emergency exists or an evacuation is required.

The effect of G6D8 is to apply the requirements of Part E4 to occupiable outdoor areas as for an internal, occupied part of the building.

Consequently, the provisions from Part E4 as applied under G6D8 are considered the minimum necessary to enable safe evacuation of occupants in case of an emergency.

For the purposes of the Deemed-to-Satisfy Provisions of F6D5, F6D9 and F6D10, a reference to a room includes an occupiable outdoor area.

To specify requirements for light and ventilation in an occupiable outdoor area.

There are a wide variety of occupiable outdoor areas. G6D9 is provided in recognition that various occupiable outdoor areas may have periods of occupation that require the provision of artificial lighting.

In addition, G6D9 applies the restrictions for sanitary facilities found in F4D9 and F4D10 to those directly adjoining occupiable outdoor areas.

For the purposes of the Deemed-to-Satisfy Provisions of G4D8, a reference to a storey includes an occupiable outdoor area.

To enable occupants to evacuate an occupiable outdoor area in an alpine area in an emergency without being impeded by lack of knowledge of the fire safety system, egress routes or evacuation procedures.

G6D10 ensures that an occupiable outdoor area is considered as a storey for the purposes of G4D8. Where a building is located in an alpine area and contains an occupiable outdoor area, it is important that the fire orders are displayed in a suitable location.