For many Australian homeowners, the setting to build their dream home is amongst an abundant bushland which provides a beautiful and picturesque setting. However, as all Australians are aware there is the ever present threat of bushfires that needs to be considered when building or renovating.
In response to the tragic Black Saturday fires in Victoria in 2009, Australian standard 3959 has been updated and the building code of Australia referenced the new standard across every state in May 2010. The updated Australian standard 3959 established updated building and construction requirements for bushfire-zoned areas, covering all aspects of the external built environment, including windows and doors.
So what does the standard encompass and what does it mean for homeowners when designing their homes in terms of specifying their windows and doors?
The old Australian standard had four levels of bushfire attack however the updated standard now has five levels of severity, expressed as bushfire attack levels or more commonly referred to as ‘BAL’. The purpose of updating AS3959 was to establish a construction technique for buildings that were more likely to withstand the attack of bushfires.
Making sense of BAL
In assessing the likely bushfire threat to a building AS3959 requires a review of the fire danger index, vegetation type, distance of the building from vegetation, and the effective slope under the vegetation. Following this assessment, each elevation of the building is designated a bushfire attack level (BAL) of which there are five:
- BAL 12.5: Low
- BAL 19: Moderate
- BAL 29: High
- BAL 40: Very high
- BAL FZ: Flame zone
In terms of windows and doors there are two options within each BAL category, prescriptive-based and performance-based, to enable a range of alternative solutions to meet the requirements of AS3959.
The prescriptive alternatives that are deemed to satisfy AS3959, involve either the fitting of a metal screen / bushfire shutter, or the construction of a window or door system to defined construction methods for the frame, glass and hardware.
The performance-based alternative requires certification and uses AS1530 tests on elements of construction for buildings exposed to simulated bushfire attack, to define the performance requirements for window and door systems.
A window or door system tested and certified under AS1530 may be used in any BAL category up to the approved category, up to a maximum height of 3000mm and an indefinite length as long as individual lites do not have a glass area larger than 2.4m².
JELD-WEN Australia and BAL 40 – window and door options
To assist homeowners and builders, the JELD-WEN Australia brands of Airlite, Corinthian and Stegbar have developed an extensively tested range of windows and doors that meet BAL 40 certification. Each brand’s BAL 40 range encompasses innovative design with stringent construction and quality components and materials, all complying with AS3959 and AS1530.8.1 specifications and independently tested by the CSIRO.
The Stegbar and Airlite premium BAL 40 ranges feature cedar, aluminium and merbau windows and doors, giving homeowners peace of mind against the threat of bushfires and eliminating the need for bulky shutters, fire curtains or screens on fixed glazing.
The Corinthian range of entrance doors includes 15 beautifully crafted doors that can be painted or stained, a choice of four different door handle options and either a hardwood or Enviro-Seal™ sill. The entrance door system includes a door with an innovative fire retardant core, hardwood frame, a specialised glazing and beading system and unique sealing between the door and the frame.