What This Requirement Covers
Bushfire planning overlays and associated development controls set out land-use planning and building requirements for areas identified as bushfire prone. These overlays are applied by state and local planning authorities to reduce life-safety risk and property loss from bushfire through land-use controls, siting and design conditions, and by referencing construction standards. They exist because vegetation-fire behaviour, ember attack and radiant heat create predictable hazards at the urban-wildland interface and in adjoining rural landscapes; planning overlays let authorities manage risk at the subdivision and development permit stage in addition to building-level controls.
These controls apply to anyone proposing subdivision, new development, change of use or substantial alterations in mapped bushfire-prone areas. They affect permit applicants, designers, certifiers and builders by imposing planning permit conditions (for example asset protection zones or mandatory setbacks) and by requiring compliance with construction standards such as AS 3959 - "Construction of buildings in bushfire-prone areas" and relevant parts of the National Construction Code (NCC). Where a bushfire planning overlay applies, both planning approvals and building code compliance must be satisfied before development can proceed.
Key Requirements
- Bushfire Attack Level (BAL): Site-specific BAL is assessed in accordance with AS 3959. BAL categories are BAL-Low, BAL-12.5, BAL-19, BAL-29, BAL-40, BAL-FZ. The assessed BAL determines construction requirements in AS 3959 (clause and table references within AS 3959 apply to materials, ember-protection and glazing requirements).
- Applicable buildings: Overlay controls and AS 3959-based construction commonly apply to residential Class 1 and Class 10a structures and, where specified by local planning or schedules to the NCC, to Class 2 to Class 9 buildings or parts thereof that are within designated bushfire prone areas (see NCC Volume One amendments and state schedules such as NSW G5D3, SA G5D5). Exact scope is often stated in planning scheme overlay wording and in NCC clauses (for example, NSW G5D3 applies to Class 2, Class 3, Class 4 parts, Class 10a and decks immediately adjacent or connected to those buildings).
- NCC references: Where an NCC requirement interacts with bushfire controls, cite the relevant clause: for example, compliance pathways and modifications for bushfire-prone areas are referenced in NCC Volume One, Part G5 and Specification 43 (see NSW-specific inserts such as NSW G5D3, NSW S43C2 / S43C11). For housing, consult NCC Volume Two references to planning controls and state schedules.
- Vegetation separation and asset protection zones (APZs): Planning overlays commonly require separation between buildings and classified vegetation. The required distance and APZ are determined by local policy or in accordance with Planning for Bushfire Protection and the site-specific BAL assessment process referenced in AS 3959. For example, some state schedules require determining APZs under jurisdictional guidance rather than using a fixed national clause (see NSW S43C2 replacement wording).
- Water supply for firefighting: Some NCC state provisions require provision of water for firefighting purposes where development is in designated bushfire-prone areas. For instance, NSW S43C11 requires availability of either a fire hydrant system complying with E1D2 or alternative water supply arrangements specified by the local authority or consent condition.
- Construction details and materials: Specific construction measures required by BAL rating are given in AS 3959 (for example, ember screens, external wall and roof material standards, glazing protection, sub-floor closures). Measurements and thresholds in AS 3959 include:
- Setbacks and slopes used to calculate flame exposure and radiant heat inputs as part of BAL assessment per AS 3959 methodology.
- Ember protection mesh aperture and material as required by AS 3959 for vents and openings (refer to AS 3959 tables for exact mesh sizes and material requirements by BAL level).
- Alternative solutions and Performance Requirements: For some building classes and BALs, deemed-to-satisfy provisions may not exist in the NCC and a Performance Solution against NCC Performance Requirements may be required (for example, certain Class 9 special fire protection buildings or buildings subject to BAL-FZ per state variations). See NCC Volume One, NSW G5P2 and associated notes.
Residential vs Commercial
- Residential (Class 1 and Class 10a):
- Most common application of bushfire planning overlays. Construction requirements for dwellings are set by AS 3959 based on assessed BAL (BAL-Low through BAL-FZ). Typical provisions include ember protection to vents, restrictions on combustible attachments, glazing protection, and specific wall/roof/cladding requirements. Many planning authorities require APZs or specific vegetation management as a condition of consent.
- Where the BAL is BAL-12.5 or higher, specific AS 3959 construction details apply (for example, ember screens, ignition-resistant materials). BAL-FZ often triggers refusal or very strict consent conditions and may require Performance Solutions.
- Commercial and higher-risk occupancies (Class 2 to Class 9):
- Application depends on state NCC schedules. Some jurisdictions (for example, NSW) explicitly extend modified bushfire provisions to Class 2 and some Class 9 buildings via NSW G5D3 / Specification 43. For larger or essential service buildings, there may be no Deemed-to-Satisfy provisions and a Performance Solution may be required to satisfy NCC Performance Requirements.
- For buildings providing essential community functions (Class 9a hospitals, aged care), fire-engineered solutions, increased separation, or sprinkler systems may be required in addition to construction measures. Reference specific NCC clauses and state schedules for mandatory water supply or hydrant systems (for example, NSW S43C11 referencing E1D2).
Exceptions and Exemptions
- Some low-risk works may be exempted under local planning schemes or building exemptions, but where a development site is within a mapped bushfire planning overlay an exemption should not be assumed. Exemptions vary by state and local policy.
- Jurisdictional schedules to the NCC may modify or remove certain national clauses. For example, NSW has replaced some national S43 clauses with NSW S43C2 (left blank where Planning for Bush Fire Protection governs APZs) and NSW G5D3/G5D4 which set out modified obligations for various classes of building.
- BAL-Low: Where a site is assessed as BAL-Low, minimal ember and radiant heat construction requirements apply; often no specific AS 3959 construction detailing is required beyond sound building practice. However, local planning consent may still impose vegetation management conditions.
- Development consent may modify construction requirements: planning authorities can impose specific conditions that alter deemed-to-satisfy requirements provided the modifications are recorded in permit wording (NSW references show where development consent can modify AS 3959 requirements - see NSW G5D3).
State and Territory Variations
- NCC includes state and territory schedules (Schedules 4-12) that may modify bushfire provisions. Key examples:
- New South Wales: NSW replaced or modified national clauses with NSW G5D3, NSW G5D4, NSW S43C11 and refers to Planning for Bush Fire Protection for APZs and consent conditions. Some Deemed-to-Satisfy paths are not available for certain BALs in NSW and Development Consent can alter requirements (see NCC Volume One: NSW G5 clauses and Specification 43 changes).
- South Australia: SA includes schedule provisions mapping Planning and Design Code risk categories to default BALs (for example, general bushfire risk areas = BAL-Low, medium risk = BAL-12.5, high risk = BAL assessed using AS 3959) as inserted in SA G5D5 (NCC Volume One inserts). Urban interface rules with 100 m/500 m distances are specified in the state schedule.
- Queensland, Western Australia, Victoria, Tasmania, ACT, NT: Each jurisdiction uses planning overlays and may have unique local planning scheme thresholds, APZ definitions and mapping practices. Always check the relevant state schedule in NCC 2022 Volume One (Schedules 4-12) and the local planning scheme overlay wording. The NCC notes that state schedules may modify or replace national provisions; verify the relevant schedule for your jurisdiction.
- Always check local council planning maps and the state bushfire-prone land maps because mapping, APZ methods and required setbacks differ by state and sometimes by council.
Practical Compliance Tips
- Obtain the official bushfire-prone land map and the local planning scheme overlay early in the design phase to determine whether the site falls under a bushfire planning overlay and which BAL methodology applies.
- Commission a BAL assessment using AS 3959 methodology and site-specific measurements (vegetation classification, slope and distance). Do not rely on casual observation - accurate measurement affects construction levels significantly.
- Cross-check BAL and planning overlay outcomes with the relevant state schedule in NCC Volume One and council conditions. For NSW and SA, check the specific inserts (for example, NSW G5D3/G5D4, SA G5D5) that may change how requirements apply.
- Where BAL is BAL-12.5 or higher, provide detailed building elevations and construction specifications aligned to AS 3959 tables for materials, glazing, vents and ember protection; include these in the development application and construction drawings for certifier review.
- Do not assume Deemed-to-Satisfy provisions always apply; some building classes or BALs require a Performance Solution or modified consent conditions. Document any Performance Solution with clear evidence and clause references to NCC Performance Requirements.
- Manage landscaping and create required Asset Protection Zones in permit conditions. Maintain vegetation management plans and show them on site plans so ongoing compliance (and future sales) is clear to owners and certifiers.
- Coordinate with your building certifier and local planning officer early if you anticipate BAL-FZ or difficult site constraints; some high-BAL sites are best avoided or require special consent conditions (for example, alternative water supply, sprinkler systems or fire authority conditions as in NSW S43C11).