DESIGNING IN BUSHFIRE PRONE AREAS

In November 2015, Baldwin O'Bryan Architects won the Bushfire Building Council of Australia's  Innovation Award for the best design concept for this design at Newee Creek in NSW.

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DESIGNING AND BUILDING IN BUSFIRE-PRONE AREAS

At Baldwin O’Bryan Architects, we design homes across all states and territories of Australia, with particular expertise in bushfire-prone regions. We also work closely with a builder who can build in most areas in Australia but particularly in Tasmania, Victoria and parts of NSW so for many projects we can  offer a design-and-construct delivery model which provides greater cost certainty and significantly reducing the risk of budget overruns during construction.

While our early work focused on earth-sheltered homes for maximum fire protection, our practice has evolved to include more conventional above-ground houses incorporating a robust, bushfire-resistant concrete shell.

We have successfully gained planning and building approvals for more than 22 homes in designated Bushfire Prone Areas, including many sites where clients were initially advised that approval was unlikely or even impossible. This success is driven by our deep understanding of state-based planning systems, bushfire regulations and approval pathways, including compliance up to BAL–Flame Zone (BAL-FZ).

Development approval and building approval in bushfire-prone areas
In Victoria, development approval is typically required where land is affected by a Bushfire Management Overlay (BMO). This process involves preparing a detailed Bushfire Management Statement (BMS) that demonstrates how the proposed development meets the objectives of Clause 53.02 of the Planning Scheme. The CFA is a mandatory referral authority, and their requirements—such as defendable space, access, water supply and building siting—must be resolved at the planning stage. Once planning approval is secured, a separate building permit is required, demonstrating compliance with the NCC and AS3959 for the assessed BAL level.

In NSW, development approval is governed by the Environmental Planning and Assessment Act and typically assessed under Planning for Bush Fire Protection (PBP). Depending on the site and proposal, approval may be obtained via a Development Application (DA) or, in some cases, a Complying Development Certificate (CDC). The NSW Rural Fire Service (RFS) acts as the key bushfire authority, issuing conditions that must be incorporated into both the design and the subsequent Construction Certificate (CC). As in Victoria, BAL assessment under AS3959 forms a critical part of the building approval process.

In both states, early integration of bushfire planning and building compliance is essential. Attempting to “retrofit” bushfire measures late in the approval process often leads to refusals, redesigns, cost escalation and lengthy delays.

Bushfire consultants and regulatory expertise
At Baldwin O’Bryan Architects, we work closely with exceptionally experienced bushfire consultants who are integral to our success in high-risk locations. In Victoria, we collaborate with Denis O’Bryan, and in NSW, with Stephen Cotter. Both are very senior bushfire consultants with decades of experience navigating CFA and RFS approvals. Together, we have achieved approvals for homes in bushfire-prone areas that many clients were previously told had no realistic chance of being approved.
Having the right professional team is critical. A refusal from authorities such as the CFA in Victoria, the RFS in NSW, or local councils can be extremely difficult—if not impossible—to overturn once issued. Early, informed design decisions, supported by senior bushfire expertise, are essential to avoiding costly refusals or redesigns.

Innovative, cost-effective bushfire construction
We have developed an innovative, cost-effective construction approach based on EPS concrete panels combined with a steel frame system.
This method enables us to achieve high bushfire performance without the prohibitive costs often associated with traditional reinforced concrete construction. One of the main challenges in bushfire-resilient design is balancing performance with affordability. While heavy reinforced concrete structures provide excellent fire resistance, they are often costly and slow to build. EPS concrete panel systems, by contrast, can deliver comparable fire performance at a fraction of the cost and with significantly faster construction times.
To illustrate, one of our clients received quotes from more than six builders, all pricing the house at over $2.4 millionusing reinforced concrete. Using our EPS panel and steel frame system, the same project was delivered for approximately $850,000.

Key advantages of the EPS concrete panel and steel frame system

• Bushfire performance: Engineered EPS concrete panels can achieve up to a four-hour fire resistance rating, enabling compliance up to BAL-FZ conditions.
• Cost efficiency: Substantially lower construction costs compared to solid reinforced concrete, without compromising fire performance.
• Thermal performance: The insulating properties of EPS combined with concrete deliver superior thermal efficiency, reducing long-term heating and cooling demands.
• Acoustic benefits: Enhanced sound insulation, particularly valuable in coastal and bushland settings.
• Design flexibility: Panels can be rendered or finished to replicate off-form concrete with minimal additional cost, supporting strong architectural outcomes.

By integrating these materials thoughtfully, we create homes that are bushfire-resilient, thermally comfortable, energy-efficient and highly durable, even in extreme bushfire environments.

The value of specialist architectural expertise
Architects experienced in bushfire-prone environments provide far more than aesthetic input. This expertise includes:

• Assessing bushfire risk and determining appropriate BAL ratings in accordance with AS3959 and the NCC
• Translating BAL requirements into buildable, compliant designs addressing materials, detailing, openings, roofs and construction systems
• Managing planning and building approvals, consultant coordination and regulatory compliance across different state frameworks
• Designing holistic bushfire strategies encompassing building siting, orientation, defendable space, ember protection, access, water supply and firefighting infrastructure

This integrated approach is far more effective than isolated measures such as upgrading cladding or adding shutters late in the process.
Engaging Baldwin O’Bryan Architects early when building in bushfire-prone areas is ultimately about resilience, safety and certainty. Through informed design, deep regulatory knowledge, senior bushfire consultants and innovative construction systems such as EPS concrete panels with steel frames, we deliver homes that are cost-effective, durable and better prepared for Australia’s increasingly severe bushfire conditions.

Bush Fire Resistant Houses.

In November 2015, Baldwin O'Bryan Architects won the Bushfire Building Council of Australia's  Innovation Award for the best design concept for this design at Newee Creek in NSW.

​Earth sheltered buildings have an obvious advantage in bushfires because the surrounding soil can provide a massive buffer against direct contact with flames and insulate the interior against the extreme radiant temperatures experienced in bushfires. 

Earth sheltered buildings generally have an entirely reinforced concrete structure, which is unlikely to be damaged by fire even without the massive enclosing earth walls. 

Most people would know that 90% of house loss in severe bushfires is caused by ember attacks from distant fires rather than the fire front itself. Earth sheltered buildings do not have the same entry points for ember attack as most conventional houses. There are no eaves, gutters, valleys, ridges or gables, and embers cannot enter under gaps in roof tiles or sheet metal and perhaps most importantly, there are no roof cavities. Flame and embers can’t enter underneath the building, which was identified as a major cause of destruction in the recent Wye River Fires.

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Earth sheltered buildings are generally designed with openings concentrated in one or two zones, mainly to minimise the cost of retaining walls. 

This makes it easier to cover all the potential ignition points with FZ fire-rated panels or roller shutters. Of course, if bushfire resistance is the main priority, the size of openings can be considerably reduced.

It is possible to design earth sheltered buildings that would survive even the worst bushfires undamaged, and we hope this technique can have a much larger role in improving the ability of buildings to better withstand bushfire attacks. 

The system has exceptional bushfire resistance with just standard glazing, as shown in the graphic above. However, the second, more robust facade shown in the two graphics below is a relatively low-cost adjustment, and it can meet the requirements of the highest bushfire attack level in Australia, Flame Zone (FZ).  The facade has magnesium oxide panels surrounding the glazing and a mechanised fire curtain or FZ roller shutter to cover the glazing in a bushfire event.

​There are always competing interests between preserving natural bushland and the need for new buildings, which unfortunately often requires destroying a lot of bushland for fire safety reasons. It is in everybody’s interest to minimise the depletion of our beautiful native flora and fauna. We hope that the technique of Earth Sheltering could eventually contribute to moving the needle on this environmental dilemma, particularly for sensitive bushfire-prone regions such as the Blue Mountains and the edges of larger urban areas.
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