NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings
Search the National Construction Code editions
Classification
Building class 1a Building class 1b Building class 2 Building class 3 Building class 4 Building class 5 Building class 6 Building class 7a Building class 7b Building class 8 Building class 9a Building class 9b Building class 9c Building class 10a Building class 10b Building class 10c

Filter

Classification
Building class 1a Building class 1b Building class 2 Building class 3 Building class 4 Building class 5 Building class 6 Building class 7a Building class 7b Building class 8 Building class 9a Building class 9b Building class 9c Building class 10a Building class 10b Building class 10c

43

Specification 43 Bushfire protection for certain Class 9 buildings

Specification 43 Bushfire protection for certain Class 9 buildings

(1) This Specification sets out bushfire protection measures for buildings described in G5D4.

(2) Compliance with this Specification does not guarantee the safety of building occupants or the maintenance of tenable conditions within a building during a bushfire event.

Explanatory information

The measures set out in this Specification are intended to operate in conjunction with other bushfire safety measures that lie outside the scope of the NCC. Information about these measures can be found in the Guide to NCC Volume One for Part G5.

To clarify that Specification 43 includes the requirements for bushfire protection measures for certain Class 9 buildings.

The aim of S43C1 is to specify the requirements related to bushfire protection measures for buildings identified in G5D4. This provision underlines the precautions and measures that are to be taken into account for the described building types.

However, it's crucial to understand that compliance with S43C1 doesn't necessarily ensure the complete safety of a building’s occupants or guarantee that the conditions inside the building will remain teanble throughout a bushfire incident. This means that additional safety measures beyond those prescribed in S43C1, such as evacuation, might be needed to sufficiently secure building occupants.

NCC Title
Separation from classified vegetation
NCC State
NSW
NCC Variation Type
Deletion
NCC SPTC Current
Separation from classified vegetation
NCC Notice
S43C2 does not apply in NSW as Asset Protection Zones must be determined in accordance with Planning for Bush Fire Protection.

(1) The building must be separated from classified vegetation—

  1. by not less than the minimum distances specified in Table S43C2; or
  2. such that radiant heat flux on exposed building elements will not exceed 10kW/m².

(2) For the purposes of (1), the term ‘classified vegetation’ has the meaning that it has in AS 3959.

Table S43C2 Minimum distance of building to classified vegetation
Vegetation classification Slope Minimum distance (m) of the building to classified vegetation
High risk Upslope and flat land 60
High risk Downslope max 20 degrees 110
Medium risk Upslope and flat land 40
Medium risk Downslope max 20 degrees 80
Low risk Upslope and flat land 30
Low risk Downslope max 20 degrees 50
Table Notes
  1. Table values are based on a Fire Danger Index of 100 in accordance with AS 3959.
  2. High risk equates to vegetation classification of forest and woodland in accordance with AS 3959.
  3. Medium risk equates to vegetation classification of scrub and rainforest in accordance with AS 3959.
  4. Low risk equates to vegetation classification of shrubland, mallee/mulga and grassland in accordance with AS 3959.

To set out the minimum distance that must be maintained between a building and classified vegetation.

S43C2 offers two options for compliance: the building can either be separated from the vegetation by the minimum distances specified in Table S43C2 (S43C2(1)(a) or it can be constructed such that radiant heat flux on exposed building elements does not exceed 10kW/m² (S43C2(1)(b)).

Table S43C2 provides the minimum distance values for the option prescribed in S43C2(1)(a), calculated based on a Fire Danger Index of 100 as prescribed by AS 3959. The table classifies risks associated with different vegetation types into high, medium, and low categories. For instance, high-risk vegetation includes forests and woodlands, medium risk includes scrub and rainforests, and low risk comprises shrubland, mallee/mulga, and grassland.

Note the term “classified vegetation” as used in S43C2 is strictly as per the definition given in AS 3959. This underlines the importance of being familiar with this standard to ensure full compliance with the provision and effective bushfire protection.

(1) The building must be located not less than 12 m from any other building.

(2) The separation distance required by (1) need not be complied with if the building is constructed—

  1. with external walls that have an FRL of not less than 60/60/60 when tested from the outside, including any openings protected in accordance with AS 3959 for BAL—19 or greater; or
  2. for external walls and roof, using a material or system that satisfies the test criteria of AS 1530.8.1 for a radiant heat flux of 10 kW/m² or greater.

To set out the minimum separation distance between buildings.

S43C3 stipulates a required minimum separation distance of 12 m between the subject building and any other building. However, there are circumstances where this distance requirement can be waived. If the building's external walls are constructed with an FRL of not less than 60/60/60 when tested from the outside (including any openings safeguarded according to AS 3959 for BAL—19 or greater), or if the external walls and roof are constructed using a material or system that fulfills the test criteria of AS 1530.8.1 for a radiant heat flux of 10 kW/m² or greater, the separation distance is not mandatory. These allowances seek to offer some flexibility without compromising safety.

(1) The building must be located not less than 10 m from any allotment boundary or open carparking area/spots.

(2) The separation distance required by (1) need not be complied with if the building is constructed—

  1. with external walls that have an FRL of not less than 60/60/60 when tested from the outside, including any openings protected in accordance with AS 3959 for BAL—19 or greater; or
  2. for external walls and roof, using a material or system that satisfies the test criteria of AS 1530.8.1 for a radiant heat flux of 10 kW/m² or greater.

To set out the minimum separation distance between any allotment boundary or open carpark areas.

S43C4 requires that the subject building be located at least 10 m from any allotment boundary or open carparking area/spots. Exceptions are made for buildings where external walls have an FRL not less than 60/60/60 when tested externally, or if they are built with materials that pass the AS 1530.8.1 test for a radiant heat flux of 10 kW/m² or higher. This provision ensures a building is provided with protection from these potential sources of radiant heat.

The external walls and roof of the building must be protected from potential hazards on the site such as liquefied petroleum gas bottles, fuel storage, storage of combustible materials, waste bins, vehicles, machinery, and the like, by—

  1. a separation distance of not less than 10 m; or
  2. where within the 10 m separation distance described in (a), constructed with external walls that have an FRL of not less than 60/60/60 when tested from the outside, including any openings protected in accordance with AS 3959 for BAL—19 or greater; or
  3. for external walls and roof, using a material or system that satisfies the test criteria of AS 1530.8.1 for a radiant heat flux of 10 kW/m² or greater.

To set out the minimum separation distance from potential site hazards.

In S43C5, the requirement for protection of the building's external walls and roof from potential on-site hazards, such as fuel storage, combustible materials, waste bins, vehicles, and machinery, is outlined. The provision stipulates a separation distance of not less than 10 m or the use of construction materials that meet the criteria outlined in S43C3 and S43C4. These precautions aim to enhance fire safety by managing on-site risks.

A non-combustible pathway directly adjacent to the building and not less than 1.5 m wide must be provided around the perimeter of the building.

To set out requirements for a non-combustible pathway around the perimeter of the building.

S43C6 mandates the presence of a non-combustible pathway that is directly adjacent to the subject building and at least 1.5 m wide. This pathway is to encompass the entire perimeter of the building. The provision of such a pathway serves to mitigate the spread of fire and facilitatesfire fighting efforts.

(1) Access pathways that lead to a road or open space must—

  1. be readily identifiable; and
  2. have an even surface; and
  3. have a minimum clear width of not less than 1 m.

(2) If the access pathway is an accessway that is required to comply with Part D4, the requirements of Part D4 override (1) to the extent of any inconsistency.

To set out the requirements for suitable external access pathways leading to a road or open space.

S43C7 focuses on the accessibility of pathways leading to a road or open space. The pathway is to be readily identifiable, have an even surface, and a minimum clear width of not less than 1 m. Where an accessway needs to comply with Part D4, the requirements of Part D4 override this provision in the event of any inconsistency. This ensures safe and unhindered access during emergencies.

An external area designed to hold people unable to be safely accommodated within the building, that may be exposed to radiant heat flux from a fire front during a bushfire event, must not be exposed to an incident radiant heat flux from the fire front exceeding 1 kW/m2 above background solar radiant heat flux.

To set requirements for external areas intended to accommodate people who cannot be safely housed within the building during a bushfire event.

S43C8 covers areas that must be designed so that the radiant heat flux from a fire front does not exceed 1 kW/m² above the background solar radiant heat flux. This provision is important to ensure safe refuge area(s) during bushfire emergencies.

To maintain internal tenability throughout the duration of occupancy during a bushfire event, the building must comply with the following:

  1. An air handling system must be provided that is capable of—
    1. being adjusted for full recycling of internal air for a period of not less than 4 hours to avoid the introduction of smoke into the building; and
    2. maintaining an internal air temperature of not more than 25°C.
  2. The building envelope must be designed such that if an air handling system required by (a) fails, then—
    1. internal air temperatures can be maintained below 39°C; and
    2. internal surface temperatures can be maintained below 60°C.
  3. If the building is divided into separate compartments then, for the purposes of (a), each compartment must have a separate air handling system.
  4. Each air handling system required by (a) must be designed to account for the activation of smoke detectors from low concentrations of smoke from external sources, so as to ensure that air-conditioning and other essential systems remain operational.

To ensure that buildings preserve internal livability during a bushfire event, achieved through efficient air handling systems and envelope design, thereby protecting the occupants from extreme temperatures and smoke infiltration.

S43C9 emphasizes maintaining internal tenability during a bushfire event. The subject building must have an air handling system capable of full recycling of internal air for at least 4 hours to prevent smoke intrusion, and maintain temperatures below 25°C. Should the system fail, the building design is to allow internal air temperatures to stay below 39°C, and internal surface temperatures below 60°C. If the building is divided into compartments each must have a separate air handling system. These systems are to account for activation at low concentrations of external smoke, ensuring continued operation of essential systems.

The building envelope must be constructed in accordance with AS 3959 – BAL 19 or greater, except that where the use of combustible materials is permitted by AS 3959, they are not to be used unless permitted by C2D10(4), (5) or (6).

To ensure the building envelope limits the use of combustible materials to enhance the building’s bushfire resistance.

S43C10 states the building envelope must align with AS 3959 – BAL 19 or greater. Combustible materials allowed under AS 3959 can only be used if permitted by C2D10(4), (5) or (6). This provision ensures the building envelope's design meets strict bushfire resilience criteria, limiting potential fuel sources during a bushfire event.

NCC Blurbs

Water for fire-fighting purposes must be available and consist of—

  1. A fire hydrant system complying with E1D2; or
  2. A static water supply consisting of tanks, swimming pools, dams or the like, or a combination of these, together with suitable pumps, hoses and fittings, determined in consultation with the relevant fire brigade that—
    1. is capable of providing the required flow rate for a period of not less than 4 hours; or
    2. has a volume of 10 000 litres for each occupied building.
NCC Title
Supply of water for fire-fighting purposes
NCC State
NSW
NCC Variation Type
Replacement
NCC SPTC Current
Supply of water for fire-fighting purposes

Water for fire-fighting purposes must be available and consist of—

  1. a fire hydrant system complying with E1D2, or
  2. a static water supply consisting of tanks, swimming pools, dams or the like, or a combination of these, together with suitable pumps, hoses and fittings, capable of providing the required flow rate for a period of not less than 4 hours, determined in consultation with the relevant fire brigade.

To ensure a reliable water supply for firefighting.

Under S43C11, a building must have a water supply for firefighting. It could either be a fire hydrant system compliant with E1D2, or a static water supply capable of providing the necessary flow rate for a minimum of 4 hours. This provision guarantees that a significant amount of water is available for fire-fighting purposes, offering an essential line of defence against bushfires.

(1) Emergency power must be provided to support, for not less than 4 hours before and 2 hours after the passing of the fire front during a bushfire event, the ongoing operation of—

  1. air handling systems to maintain internal tenability; and
  2. any pumps for fire-fighting; and
  3. any emergency lighting and exit signs; and
  4. any other emergency equipment listed in C3D14(6) and required to be provided.

(2) Manual control for emergency back-up power supply must be provided to facilitate manual intervention where the power supply fails or runs out.

To ensure emergency power is provided to maintain crucial systems during a bushfire event.

S43C12 mandates the provision of emergency power for at least 4 hours before and 2 hours after a fire front during a bushfire event. The power must support air handling systems, fire-fighting pumps, emergency lighting and exit signs, and any other emergency equipment. Manual control for the back-up power supply is to be available for intervention if the power supply fails or runs out.

Signage must be provided to warn building occupants against storing combustible materials under or adjacent to the building.

To set out requirements to prevent fire risk elevation by mandating signage.

S43C13 instructs that signage be provided to caution occupants against storing combustible materials under or adjacent to the subject building. This provision limits potential fire risks by discouraging practices that might heighten the vulnerability of the building during bushfire events.

Vehicular access to the building must be provided in accordance C3D5(2), as if the building were a large isolated building for the purposes of C3D4.

To set out requirements for firefighting vehicles access.

S43C14 requires that vehicular access to the building be provided in compliance with C3D5(2), treating the building as a large isolated building for the purposes of C3D4. This provision ensures that firefighting vehicles can access the building efficiently and quickly, which is crucial for effective bushfire response.