Bushfire attack levels (BAL) explained for Sydney homeowners

Short answer: A bushfire attack level (BAL) describes how much a building is at risk from embers, burning debris, heat and flames in a bushfire. There are six levels: BAL-LOW, BAL-12.5, BAL-19, BAL-29, BAL-40 and BAL-FZ. The higher the level, the more protection the building needs, and the stricter the construction requirements.

If you’re building or extending on bush fire prone land, your BAL shapes which materials and details you can use.

Why it matters in southern Sydney

The Sutherland Shire sits beside the Royal National Park, and plenty of homes across Georges River and Canterbury-Bankstown back onto bushland along the river and its creeks. Parts of these areas are mapped as bush fire prone land, so check your property before you plan work.

The six levels

The NSW Rural Fire Service describes the levels like this:

Level	Description of risk
BAL-LOW	Lowest risk from a potential fire
BAL-12.5	Risk is mainly from embers during a fire
BAL-19	Moderate risk, particularly from embers and burning debris
BAL-29	High risk, particularly from embers, debris and heat
BAL-40	Very high risk. Likely to be affected by embers, debris, heat and possibly flames
BAL-FZ	Extreme risk. Directly exposed to the flames of a fire front

How your BAL is worked out

According to the RFS, your BAL depends on:

• the area you live in
• the vegetation near your home
• the distance from that vegetation to your home
• the slope of the land

Your BAL is confirmed in a written report, usually by a bushfire consultant or through the NSW RFS, as part of the approval for new work. The RFS also has a free household assessment tool that gives you an idea of your risk.

What changes for common jobs

Extensions and new builds. Construction requirements for each BAL are set by Australian Standard AS 3959. They cover things like cladding, windows, decking and subfloors, and come through the approval for the work.

Decks, pergolas and carports built without approval. Under the NSW exempt development rules, if the property is on bush fire prone land, walls of a deck, pergola or patio within 5 m of the house must be non-combustible. A carport within 5 m of the house must be built from non-combustible materials. See our guides to deck and pergola approvals and carport approvals.

Fences. Exempt fences on bush fire prone land must be non-combustible or hardwood. See fence height rules.

Garden sheds, cabanas and cubbies. Exempt structures on bush fire prone land must be built from non-combustible materials.

Choosing decking and cladding

The right decking and cladding depend on your BAL. Many products are tested and rated for particular levels. Check each product against AS 3959 for your level before you buy. We confirm a product’s rating before we order it.

How we handle it

Before we quote work on bush fire prone land, we ask for your BAL report or check whether one is needed, then choose materials and details to suit.

This guide was checked against NSW Rural Fire Service and NSW Planning sources in September 2026. It’s general information, not a BAL assessment.