What is a BAL Rating?

A Bushfire Attack Level (BAL) is a way of measuring the severity of a building’s potential exposure to ember attack, radiant heat and direct flame contact.

If you are building a new home within a BPA (bushfire-prone area), then you’ll need a BAL assessment. All new homes constructed in a BPA must be built to a minimum BAL 12.5 to help withstand ember attacks. This includes sealing roofs, sealing around doors and windows and screening windows. To determine whether your property is in a bushfire-prone area, head to your local government website:

VIC – VICPlan 
NSW – NSW Rural Fire Service Website 
QLD – Queensland Fire and Emergency Services 
ACT – ACTmapi 
TAS – LISTmap TAS
SA – SAPPA 

There are 6 different categories of BAL ratings, ranging from low risk to extreme flame zone as shown here:

BAL LOW – Very low risk
BAL 12.5 – Low Risk
BAL 19 – Moderate Risk
BAL 29 – High Risk
BAL 40 – Very High Risk
BAL FZ – Extreme Risk

These levels are based on: location, vegetation, proximity of the house to vegetation and the slope of the property. A BAL rating dictates both the construction methods and the type of materials used when building dwellings within bushfire-prone areas.

Design Considerations for BAL-Rated Homes

Material Considerations

Steel Frame and Structure

All Arkular modules are built using a steel frame system. The system is designed to resist ignition and not provide additional combustible material whilst also being extremely durable within rural and coastal environments.

Timber           

Arkular uses fire-resistant timbers such as; blackbutt, spotted gum, merbau, turpentine, red ironbark, red river gum and Silvertop ash dependent on the specified BAL rating.

Cladding

Corrugated Steel is a low-maintenance fire-resistant façade used throughout homes, it also helps to reflect heat, assisting in keeping the building cool in summer.

Image: Fish Creek House > BAL 29 Rating

Image: Fish Creek House > BAL 29 Rating

Landscaping Considerations

Driveway and Surrounding Areas

Weeds, leaf litter and any shrubs that could fuel a fire should be removed from the property. Some big trees and fire-resistant plants can be left to reduce the risk of heat and ember attacks.

Roofing

Roofs are incredibly vulnerable during a fire, with the inclusion of specific design features such as gutter guards and simplistic roof structures assisting in limiting the chance of roof ignition.

Water Management

Rainwater Tanks and Sprinkler Systems 

Many bushfire-prone areas may require water tanks to be installed on-site specifically for firefighter access. These tanks must be above ground and made from special, non-combustible materials and correct fittings.

Another important feature of a fireproof house is a sprinkler system, which should spray water that is pressured to 300kpa. Sprinkler systems can aid in the survival of buildings (and people) during a bushfire, helping manage ember attack.

Yes, Arkular can Build in Bushfire-prone Areas

At Arkular, we have extensive experience in designing homes in a range of rural locations, including BAL-rated areas up to Flame Zone.

To begin, we check for the correct placement of the home in accordance with bushfire management plans (BMO) or BAL ratings (bushfire attack level) and work with a BAL assessor to meet the necessary regulations.

The position of the dwelling in bushland, the amount of dense vegetation and the level of road access will impact the home’s risk assessment and therefore change the requirements, which may incur additional costs as the bushfire risk increases.

During the design phase, we carefully select the correct non-combustible materials depending on the property’s BAL rating, with these requirements being strictly regulated in order to receive planning approval.

BAL ratings of 40 to Flame Zone, are typically fitted with toughened glazing, reinforced window frames, metal screens and shutters, wall wraps for complete sealing, and exterior cladding in either fibre cement or steel sheeting.

The overall management of the property must also be carefully considered, including creating access to paths for firefighting vehicles, installation of water tanks and clearing vegetation.

View 5 Arkular modular homes that have been designed according to different BAL ratings here, or contact us to get started on your BAL-rated project.

Arkular’s Flame Zone Home 

A home designed for the most extreme level of fire rating, the Ark Flame Zone Home fully complies with the most extreme BAL rating requirements, including:

– Analysis of the property in collaboration with the bushfire consultant
– Form extrudes over the veranda, so there is a refuge and protection from the elements
– The exterior is clad in Fire Crunch, a lightweight material that resists fire, water, sound, termites, impact and mould
– Thicker glass windows and sliding doors than standard with the highest quality finish with a priority to maximise safe solar gain and views
– Customisable position of the modular home and windows to reduce bushfire risk by planting vegetation as a fire blocker, not a starter
– Commercial fire-rated doors and windows
– DecoDecking deck, an attractive yet fire-safe alternative to the traditional timber deck
– Customised to the site with necessary tweaks will be required to meet individual requirements
– External shutters are concealed behind all openings, and fire collars are to all penetrations

View the full Flame Zone Home design here.

Image: Arkular Flame Zone Home > BAL FZ Rating 

Preparing Your Home for the Bushfire Season

Everyone should be prepared and stay up to date with the latest news and information, whether you are in the bush, by the coast or on an urban fringe.

Prior to bushfire season:

– Keep lawns mowed regularly
– Removed excess combustible material (leaves, dry grass, branches)
– Move any flammable items (paper, wood, boxes)
– Keep gutters clear
– Pack an emergency kit
– Prepare your bushfire emergency plan

As bushfire season approaches, stay informed by checking daily fire ratings and using more than one form of information source for safety. Everyone has a role to play in planning for bushfires – including fire authorities, landowners, land managers, local councils, and the community.

To learn more about preparing for bushfire season head to one of the following resources or check your local government organisation:

CFA – How to Prepare Your Property 
VIC Gov – Plan and Prepare 
ABC News – How to Get Ready for Bushfire Seasons

Image: Arkular Flame Zone Home > BAL FZ Rating 

Sources and Additional Reading

– Country Fire Authority
– Building in Bushfire Prone Areas Victorian Government 
– Victorian Building Authority (Bushfire Overlays)
– The Indian Ocean Dipole (IOD)