How a bushfire meets a window
The Country Fire Authority’s page on fire resistant home improvements says embers are the main way homes are lost in a bushfire, and that the wind carries them ahead of the fire front, starting fresh fires wherever they land around a house or find a way inside. It also warns that radiant heat can break glass, and can set alight woodpiles, outdoor furniture or plants close to a house before any flame reaches them. A window left open, or fitted with no screen, is described there as an extreme fire risk: once heat breaks the glass, the embers have a way in.
The NSW Rural Fire Service’s page on building on bush fire prone land calls glazing one of the building elements most exposed to radiant heat and flying debris, and adds that much of that heat can come in through the glass and warm the things inside the room: carpets, curtains and furniture. The same page calls windows and doors vulnerable to bush fire attack, and possible entry points for embers.
What each state’s page says about the glass
Four official pages, from four states, carry a view of what should happen at a window or an external door, and each puts it its own way. Building and Energy in Western Australia, for a retrofit up to and including BAL 29, asks for toughened safety glass where metal screens or bushfire shutters are not fitted; the Queensland Government lists shutters or toughened glass among the measures new homes in its most extreme fire risk areas will need; the CFA in Victoria advises metal screens over the window and its frame, or shutters; the NSW Rural Fire Service asks for glass thick enough to stand a fire’s heat, with metal screening where it is needed.
| State and agency | What its page says | Page read on |
|---|---|---|
| Western Australia, Building and Energy | Its examples are for retrofitting an existing home up to and including BAL 29, work that may need a building permit; above BAL 29 it sends the owner to a building surveyor or another qualified and experienced practitioner for advice. Among them it puts screens and shutters first: a window should carry metal screens or bushfire shutters. Where those are absent from a window or an external door, it says the glass should be toughened safety glass. For a sliding door it asks for metal screens too, mesh or perforated sheet in corrosion-resistant steel, bronze or aluminium, or bushfire shutters, and the hardware on them, it adds, should be metal. | Building and Energy page, read 8 October 2026 |
| Queensland, Queensland Government | The page says the measures required for new homes in the most extreme fire risk areas will include shutters made from aluminium or other non-combustible material, or toughened glass for windows. It also says Queensland has adopted AS 3959-2018, which sets out the requirements for the construction of buildings in bushfire prone areas in order to improve their safety when they are subjected to burning debris, radiant heat or flame contact. | Queensland Government page, read 8 October 2026 |
| Victoria, Country Fire Authority | For a window, the CFA advises screens of metal, and not aluminium, pierced with 1.5 mm holes and fitted across the frame as well as the glass, so that burning debris cannot touch the glass or the timber, or come in through a pane that has broken. Shutters, it adds, cost more but protect better than mesh, and can keep a window from cracking under radiant heat or flying debris. | CFA page, read 8 October 2026 |
| New South Wales, NSW Rural Fire Service | For windows, the RFS says the glass must be thick enough to stand the heat of a fire, and that metal screening may be needed to keep embers out of the building. External doors, it says, need to be made of materials that resist the spread of fire, with proper seals. It is also plain that no one measure on its own is enough. | RFS page, read 13 October 2026 |
The documents are dated differently as well. Queensland adopted AS 3959-2018. New South Wales works from Planning for Bush Fire Protection 2019, the statutory document its Rural Fire Service produces, which sets the standards and requirements for development on that land and helps applicants, councils and consultants work out which bush fire protection measures a proposal needs. In Western Australia, a newly designated bushfire prone area gets a four-month transition period, under the Building Regulations 2012, before the construction requirements for bushfire that sit in the Building Code of Australia reach certain buildings.
And the parts of a building these requirements reach are not only the glass: the Standard covers walls, roofs, flooring and eaves, gutters and downpipes among them, along with external doors, windows and screens. What has to be built depends on the Bushfire Attack Level, the same page says.
How a Bushfire Attack Level is set
The level in question is a Bushfire Attack Level, and this guide does not set one. Building and Energy in Western Australia says the Standard requires an assessment of the building to work out its level, and that what has to be built depends on that level, with the levels set by an assessment of the surrounds: the slope of the land, the vegetation, and how near other structures or buildings stand on the site. The NSW Rural Fire Service defines the level as a measure of how severely a building might be exposed to ember attack, to radiant heat and to direct flame contact, expressed in steps of radiant heat in kilowatts per square metre, and says the construction required depends on the level determined for the property. Its page adds that for complying development, the fast-track approval open only on land rated BAL Low to BAL 29, the level can be endorsed only by the local council or an accredited bushfire consultant. On a development application, the level is confirmed in a written report: many people prepare it with a bush fire consultant, and a household can also do the assessment itself with the Single Dwelling Applicant Kit, though the page warns that could slow the process if the council asks for more information.
None of that rates the risk at any particular house, and nothing in this guide does either. The level is set for a place by an assessment of that place, done by the people the pages name.
Finding out whether a property is on that land
The Queensland and NSW pages start with the same question, and both answer it through the local council. The Queensland Government’s advice is to check with the local council whether a property is in a designated bushfire prone area, which it defines as land declared by local governments as likely to be subjected to bushfires. The NSW Rural Fire Service says a buyer should check, when buying land or a house, whether the property sits on land mapped as bush fire prone; the check can be made through the local council, or with the online Bush Fire Prone Land Tool. That land, in its terms, is land the local council has identified as able to support a bush fire or as subject to bush fire attack, mapped by the council, with the Commissioner of the RFS certifying the maps.
What the pages say about glass already in place
The NSW Rural Fire Service says upgrading an existing home is not something the rules force, though it strongly recommends the measures as a way of making a home safer in a bush fire. Building and Energy in Western Australia notes that building standards, as a rule, do not reach back: buy a house in an area that was declared bushfire prone after the house was built, and the law may not require it to be upgraded. The same page is careful about what any of it promises: fire behaves unpredictably and weather turns extreme, so no building is guaranteed to survive a bushfire, and the Standard’s aim is to improve how buildings perform when one attacks. The Queensland Government’s page says its residential building standard applies to new homes or outbuildings, to rebuilding them, to repairing part of a building or outbuilding (it gives a garage, shed or fireplace as examples), and to additions within six metres of a dwelling.
For retrofitting a home up to and including BAL 29, where metal screens or bushfire shutters are not fitted, the Western Australian page names toughened safety glass, and says the work may need a building permit; above BAL 29 it sends the owner to a building surveyor or another qualified and experienced practitioner for advice, and what has to be built depends on the level set for the site.
The guides on either side of this one
Why toughened glass is what comes up here is set out in laminated or toughened: how each one breaks, and where safety glass is asked for in a home at all is the first guide, where the code asks for safety glass.
The steps themselves, for a household preparing for a fire season, are on the agencies’ own pages, listed at the foot of this page. This guide has stayed with the glass: where the pages name it, and nothing further.