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We are committed to a sustainable future with architectural flexibility and style.

All products are suitable for new builds or retrofitting.

Ph: (03) 5338-1797Ph: (03) 5338-1797


Bushfire Window Solutions

Sonnenschutz make shutters for all BAL levels. Our BAL FZ shutter system is the hero product, where we are the most cost-effective tested solution for BAL FZ window protection.

We are the only supplier that can offer you hinged shutters, roller shutters and rated windows. This is a big advantage for you, for 3 reasons:

-       We can offer a combination of products for your project, and deal with all openings

-       We can be frank about the strengths and weaknesses of each system

-       We can guide you to lowest cost or take care of high end architectural builds



Bushfire DangerBushfire Danger


Hinged shutters

These shutters provide the highest level of safety, at the low end of cost. With less than 3kW/m² of radiant heat through the window during the AS1530.8.2 test, this is less than half the heat transfer of the nearest alternative product. Openable after the fire, this solution allows for safe egress. These shutters are manually operated and will be in the range of $750/m² to $1500/m², depending on the window layout.


  Please see Gallery  for more Images  



Roller shutters

Roller shutters, with their stainless steel slat curtain, sit around the middle of hinged shutter cost, at around $1100/m². They transfer +7kW/m² of radiant heat through the window during the AS1530.8.2 test. These shutters are typically motor driven with a manual override. They cannot be opened post fire, as the headbox and drive will most likely be damaged, and the curtain seized in the tracks. This must be a consideration when a full perimeter is being shuttered, as it could result in people being trapped in the house.


 Please see Gallery  for more Images  



BAL FZ rated glazing

Windows that are rated to BAL FZ without the need for shutters will have frames of either steel or heavy timber. Aluminium is not possible as it melts in the BAL FZ test. To pass AS1530.8.2, the fitted glass will be an ‘intumescent’ glass which consists of many layers. One or more of the layers will ‘intumesce’ or swell on the application of heat, creating a thick, opaque barrier to the fire’s heat. Commonly, these windows will have around 6kW/m² inside during testing. It is not uncommon for these windows/doors to cost $3000/m²+.


The intent of any build in BAL FZ is twofold:

  1. Stopping fire entry to the building
  2. Preventing excess heat that could cause combustion of curtains, carpets etc, and heat that we cannot survive. This is why the radiant heat numbers are important. 10kw/m² is problematic in minutes. 15kw/m² blisters human skin in seconds. Outside, BAL FZ, will be in excess of 70kw/m².

With any shutters, you do get the added value of window protection, not just for bushfire, but in hot weather, for security or privacy. If you are budget constrained, you can certainly get to a compliant window solution for less cost. It is also entirely probable the house will be liveable post the fire.

With windows, you can possibly get more architectural freedom but It will be at the highest end of cost. Furthermore, post fire, the house would likely be unliveable until the windows are replaced.


Talk to us about your needs, and feel free to view our Gallery for a sample of our works.