Custom home builder in bushfire area, difficult sites, unusual construction, mud brick, Timbercrete, sloping sites, split levels, raked ceilings, steel frame, timber log homes. Current designs for new homes in high bushfire prone areasDesign & constructing homes in bushfire area's in Sydney, Hills District & the Blue Mountains

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(02) 4577 4912


Unit 1, No.103 Railway Road (North) MULGRAVE NSW 2756

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Proud Members of the
Master Builders Association of  NSW since 1968

Bushfire Protected Designed Homes

O'Mara Constructions has extensive experience designing & building new homes in high bushfire prone area's. Having lived in Hawkesbury all of our lives and with many of our sub-contractors we have experienced many bushfire's and seen the extent of fire on newly constructed homes & existing dwellings.



As per AS3959 which is the Australian Standard for Construction of buildings in bushfire prone areas there are six categories of bushfire attack levels. They are;

  • LOW
  • BAL 12.5
  • BAL 19
  • BAL 29
  • BAL 40

BAL simply means "Bushfire attack level"

Flame zone is the highest level of attack and is usually when a site backs directly onto this bush, surrounded by bushland or at the top of a steep embankment. The BAL rating can be classified by self assessment or by a fire consultant but needs to be approved by council after consultation with the RFS (Rural Fire Service)

The categories of attack are determined by:  

  1. The type of vegetation
  2. How close your building is to the vegetation
  3. What the effective slope is (i.e. fire runs more readily and with greater intensity uphill)
  4. The Fire Danger Index applicable to the region


New deck at Mount Wilson in high bushfire prone area

New deck using fire retardant treated timber

Mt Wilson completed 2008


Homes that are designed in bushfire prone area's need special consideration in design of certain construction elements.

The main considerations are, but not limited to;

  • floor framing (stumps, bearers & joists)
  • flooring sheeting & decking
  • sub-floor area enclosure
  • verandah posts & beams
  • windows & fly screens
  • water & gas pipes
  • water tank design & location
  • water pump & fire pump design & location 
  • gas bottle location
  • fire bunker design
  • external doors & garage doors
  • fascia & eave cladding
  • gutter & downpipes
  • roofing materials
  • roof penetrations & vents
  • balustrade & handrails
  • roof access
  • roof design
  • valuables safe for fire
  • roof penetrations

Gunderman home in bushfire prone area

New home near Wisemans Ferry in bushfire zone

Home with water tanks, metal cladding, gutterguard, rear deck

New deck using fire retardant treated timber


Many hopes built in bushfire affected area's are on sloping sites. This means standard slab on ground, brick veneer, tiled roof design, similar to many project homes simply don't work or any much too expensive and not practical.

There are numerous ways to design a home to suit the natural fall of the block in an economical way using specific materials that are lightweight but also bushfire proof. 

There are numerous cladding products that are not suitable and need to be selected depending on the BAL rating. There are also numerous types of floor systems that can be used to reduce costs, take advantage of any possible views, make sub-floor storage possible and be fire safe.



We can also use a specialised block for high bushfire area's that will greatly assist in making the home safer. These are called "Timbercrete Blocks". They are available as bricks, blocks or panels in a wide variety of sizes, shapes, colours & textures. Timbercrete is a environmentally sensitive masonry block that is proudly Australian invented & owned.

Timbercrete is made from discarded timber (containing carbon) with other special additives moulded into blocks. They have great insulation when compared to normal brick veneer or clad homes. They are very easy to work with being lighter in weight than concrete blocks, look better and can be nailed and screwed just like timber. But there huge advantage is their improved fire rating when compared to other products. The standard 190mm block has a FRL240/240/240 which is excellent

It is a great product that we highly recommend and are happy to use on any of our projects. Please go to their website for more information



Leura Timbercrete home in bushfire area

New carport using Timbercrete blocks and curved roof

New home using Timbercrete blocks fireplace

New home using Timbercrete blocks


There are numerous "passive" controls methods of protecting the home from bushfire.

Each project needs to be evaluated on a case by case basis but can include any or a combination of the following items to provide protection;

  • overall house bushfire design
  • brickwork & blockwork
  • external cladding
  • compressed fibro
  • fire retardant treated timber
  • wire mesh screens
  • fire shutters
  • window glass selection
  • seals to windows, external doors
  • garage door design
  • gutterguard
  • roof access
  • signage
  • Assest Protection Zones
  • landscaping
  • pump location
  • tank location


Custom built Australian Colonial Home in a bushfire area

110,000 litre concrete water tank poured on site with storz valve for bushfire & RFS connection

Blue Mountains Country Home
Mt Wilson completed 2008


Other considerations need to be made for specific "active" control methods, such as;

  • water tanks, swimming pools, dams, wells, rivers
  • pumps
  • storz valves
  • hose reels
  • hydrants
  • sprinkler systems
  • driveway construction & access roads
  • gutterguard

We also need to consider the materials used, the location of services, access to site, maintenance, just to name a few.We can design & construct a fire bunker. This is NOT design as a safe haven but more as a last option when escape is not possible

We can design & construct a fire sprinkler system with back-up hose reels supplied by a pool/tank/dam to protect the home to suit the site conditions and owner requirements More information can be found at the NSW rural fire service website;


Fire sprinkler system - sprinkler head close up

Fire sprinkler system - custom designed

Fire hose reel for owners use in bushfires


We have current designs of homes that although can't guarantee complete bushfire protection they can at least be adapted to minimise all possible risks and increase the safety of the owner and their possessions to suit the conditions on site.

All our design will need to be viewed and approved by the RFS priory to any approval be ing granted by council or any work commencing on-site

Central McDonald new home

Home in bushfire bal rated area

Bal rated new home

New home on sloping site


There are numerous special requirements for BAL bushfire rated homes whether being BAL 12.5/19/29/40

However FZ (Flame Zone) bushier rated homes have numerous very specific requirements that differ from other BAL ratings.

These can add a lot of cost to the construction of a home compared to other BAL ratings and can easily be an additional $100,000 to $200,000 or more, depending on the site conditions & RFS requirements

There are however ways to reduce these costs while maintaining the high bushfire protection required for FZ area's in a practical way.

Please contact our office for more information

Bushfire resistant metal cladding

Fire resistant deck and balustrade

Stainless cable balustrade with metal top rail

Colorbond metal cladding in bushfire area


The rules for requirements for bushfire shutters in FZ areas have recently changed.

Where previously a standard type roller door could be used fire shutters now have to be FZ rated.

These shutters are much more detailed, more expensive and can be manually or electrically operated.

There are also rules on how they are to be operated to ensure safety of the home during a bushfire event.

Please contact our office for more information


Flame Zone rated window fire shutter (Manual operated)

Flame Zone rated window fire shutter (Manual operated)

Flame Zone rated window fire shutter (Manual operated)

Flame Zone rated window fire shutter (Electric operated)


No one can (or at least should) guarantee that if you build a new home in a bushfire affected area that it will ever be "bushfire proof". Sometimes the fire is just too powerful & fast. 

However there any many ways that you can increase your chances of protecting your home and make it alot safer. Some are expensive and are not negotiable by the RFS & council. There are however many small design changes & material specifications that can be made that don't cost a fortune and will increase the fire protection of your new home, extension or renovation.

Please contact our office for advice on how to improve the fire protection of your proposed new project.

Flame Zone rated window fire shutter (Electric operated)

Water tank for bushfire fighting 

Storz valve for RFS connection

Custom built fire pump cover