era | Building for Bushfire
are you designing + building architecture in a bushfire prone area?
Have you prepared the design of your architecture for a bushfire?
Have you prepared the existing architecture you are living in for a bushfire?
Are you living in an existing house or building a new house in a zone with a BAL rating?
What do you know? Are you ready?
So many questions!
We live in an amazing country - Australia - full of vast lands and huge blue skies, days of snow and days of exquisite sunshine, beaches and bushlands, and bushfire.
The Blue Mountains, where we live, is a series of small villages dotted along a main roadway that crosses a picturesque landscape of dramatic escarpments. To the north and south is world heritage listed National Park rolling on as far as the eye can see.
On the seventh day of September – seven days into the bushfire season – I attended the 2019 Bushfire Building Community Forum and Expo for the Blue Mountains in Springwood, New South Wales.
I want to say how FANTASTIC this day and the same day last year was. It was clearly organised, the information delivered was useful and the trade expo was a mix of genres .. It was evident that the community were interested based on the turnout and positive comments being thrown about by attendees.
I am not a fire fighter, a member of the Rural Fire Service or any other authority, but I wanted to share some useful information that I have learnt from these expos and in designing our own home that may affect the little ways in which you can design + build your architecture to make things work for you in the event of a bushfire.
I feel that, if you know these things going in, you can consider them in your design to make it work best for you.
So this is my take on things …
GATHER INFORMATION for Your Architecture.
If you gather information about how bushfire works and take on advice from the people who work with bushfire every day, then combine this information with current regulation and suitable material products,
thIs creates a brief to inform how your architecture can best perform to suit you if a fire comes through.
Let’s talk about the bushfire first.
Bushfire is an incredible force! Each season, bushfires teach locals, scientists and fire fighters more and more about how they work. And the way that fires work are changing. So the things we knew are changing and new ways in which a bushfire behaves and moves are becoming evident.
For instance, bushfire used to be thought to be directed by the predominant winds. The wind and fire were independent, but one fanned the other. And while this was and is true, it is now being seen that bushfires are creating their own winds. They become so huge that they create their own fire storm, which is independent of the winds and other weather patterns around them. This makes it hard to predict which way a fire will burn. Scientists and fire fighters have been experimenting with sending little devices up into these storms to measure the fire in the hope that they can then determine where it will head. Remember Dorothy in the film Twister? That’s the sort of thing they are doing! This technique has helped to warn people in advance of the direction a fire is headed so that they can prepare or leave in time.
How a bushfire attacks
FIRST with Embers – Embers can be transported many kilometres ahead of the actual fire front
SECOND with Radiant Heat – Radiant heat also travels ahead of the fire front
THIRD with the Fire Front – Otherwise known as the Actual Fire
When a fire approaches there are two options:
1. Leave Early
2. Take Shelter
Whether you are staying or going, prepare an emergency kit with first aid and the like – check out the Rural Fire Service web page for more detail.
If you cannot leave, or choose to stay while the fire comes through, you will need to find shelter – in other words, you will need to shelter in your home.
When the actual fire comes through it will be NOISY! The fire will be cranking and roaring … it will be scary.
Here are some tips I learned:
If you stay, you need to find two forms of shelter:
1. Inside Shelter for before and when the fire front comes through.
2. Outside Shelter for after the fire front comes through and particularly if your house is burning.
this one is VERY important
The regulations currently used to design houses for bushfire help your home survive a fire front as it comes through. To put a time frame to it, the materials or construction will survive for a minimum of 30 minutes before they may then fail. Depending on which materials you use to build with, and even if they are rated with the highest bushfire level to resist a fire for those 30 minutes, they may also be damaged and need to be replaced after the fire.
In other words, your home may not be FIRE PROOF.
It may have only been designed and built to resist the affects of a fire for 30 minutes.
That is why finding shelter in an appropriate place - before, during and after the fire has come through - is very important to surviving a fire.
And knowing that the materials may be affected and need to be replaced after, may help you choose the right materials for you. That means that you are choosing materials, not just for the actual fire itself, but for the ramifications after it has passed.
A professor who studies bushfire and where to shelter provided the following advice:
- Shelter close to an exit point so that you can come in and out to combat embers or spot fires and watch the fire progress or escape if you need to.
- Ideally, locate yourself near a water source.
- Locate some shelves or a cupboard close to where you will shelter for a place to store woollen blankets, fire extinguishers, buckets, other fire fighting gear and the like.
- If need be, drench blankets with water and cover yourself.
- Shelter on a non-combustible surface such as a paved area or the roadway.
- Ensure there are no overhanging trees or dense vegetation nearby.
- Ideally, locate yourself near a water source.
- If need be, drench blankets with water and cover yourself.
Practical tips from fire fighters.
The following are all practical tips provided by the Rural Fire Service to help you prepare for a bushfire.
You can find all of their current information on their web page. Take a look at the resources listed at the end of this blog.
Block drain pipes with socks full of sand and fill gutters with water. Don’t get on the roof to hose it down.
Patrol the house well before the fire arrives to put out embers and spot fires.
As the fire approaches, wet the side of the house and garden that faces the fire.
Move your fire fighting equipment to a place where it wont burn inside.
Close doors, windows and vents.
Fill baths, sinks, buckets and bins with water.
Confine pets to one room.
Place ladder next to roof access holes so you can check for spot fires.
Soak towels and rugs and lay them across external doorways.
Move furniture away from windows.
WHAT TO DO DURING [as the fire is upon you]
If flames are on top of you or the heat becomes unbearable move inside until the fire front has passed [usually 5-10 minutes].
Patrol the inside of your house, including the roof space, looking for sparks and embers.
Shelter in a room on the opposite side of the house from the approaching fire and ensure you have clear access to an exit.
WHAT TO DO AFTER [immediately after the fire has passed]
Check the house both inside and out for fires including roof cavity, under the house, deck, stairs, windowsills, etc.
If possible, and safe to do so, check all your neighbours are ok.
Contact relatives or friends to tell them you are safe.
Patrol your home for several hours, looking for small fires and burning embers.
FIRE FIGHTING EQUIPMENT YOU MAY NEED
A hose, or hoses, that can reach all around the house.
Water supply of at least 10,000 Litres eg. Water Tank, Dam, Pool.
Petrol | Diesel water pump and fuel in a safe, accessible place.
Ladders to access inside the roof.
Buckets and mops.
Shovels and rakes.
PROTECTIVE CLOTHING YOU MAY NEED
Wide brimmed hat.
Eye protection goggles.
Moistened facemask or cloth.
Loose, long sleeved cotton shirt.
Long cotton pants | jeans.
Sturdy leather shoes or boots.
A summary of tips from the Rural Fire Service.
TOP FIVE ACTIONS TO MAKE YOUR EXISTING HOME SAFER
TRIM: Trim overhanging trees and shrubs. This can stop the fire spreading to your home.
MOW: Mow grass and remove the cuttings. Have a cleared area around your home.
REMOVE: Remove material that can burn around your home [eg Door mats, wood piles, mulch, leaves, paint, outdoor furniture]
CLEAR: Clear and remove all the debris and leaves from the gutters surrounding your home. Burning embers can set your home on fire.
PREPARE: Prepare a sturdy hose or hoses that will reach all around your home. Make sure you’ve got a reliable source of water.
TOP FIVE ACTIONS TO MAKE THE DESIGN OF YOUR ARCHITECTURE SAFER
BLOCK: Block up areas where embers can enter the house.
INSTALL: Install metal fly screens on all windows and vents.
DIRECT: Direct any pressure valves away from house.
MOVE: Move garden beds away from house.
USE: Use stones instead of vegetation as mulch.
‘Landscaping for bushfire is much the same as any type of gardening. It involves planning, designing, planting and managing the area around your house. Design and plant selection for bushfire can reduce the effects of direct flame contact and radiant heat on your house. When considering landscaping in a bush fire area you should aim to locate trees, shrubs, plants, mulch and other landscape features:
- So that they prevent flames touching your house
- Provide a space around the house to allow you or fire fighters to protect the house
- Reduce ways for the fire to spread around and into your house
- Deflect burning debris in the air away from your house
- Use trees located away from your house to trap burning debris in the air
- Providing shelter from the heat you feel from the bush fire
- Reducing the speed of the wind around your dwelling’
RURAL FIRE SERVICE
Always check which current regulations apply to your place - wherever you may be!
In New South Wales, Australia at this time, the Rural Fire Service is the authority for all things relating to bushfire and how to build in an area prone to bushfire.
They have a lot of information and resources available to learn and refer to when it comes to designing architecture. You can find information on their web page.
In addition, Australian Standards define material and construction requirements for building.
AS3959 Construction of buildings in bushfire-prone areas
AS1530 Methods for fire tests on building materials, components and structures
As more information is gathered and learned about how bushfires behave, regulations change to inform how to build in these areas. The information is constantly evolving, so check what current regulations apply to your place before proceeding.
‘Driveways and access roads onto your property should be designed so that you can leave safely during a bush fire, while allowing fire trucks on to your property to provide property protection. Short driveways or access roads are preferable to long driveways or access roads. This is so you can leave safely during a bush fire and fire fighters can access your property easily.’ RURAL FIRE SERVICE
As information is gathered and regulations change, material manufacturers scramble to keep up.
They are required to test the materials they produce in order for them to comply with the current regulations that we build to. As such, there is usually a lag time between when the regulation is released and when material products for the parts of your architecture are available to use.
At first, there will only be a few materials available whose manufacturers have completed the required tests to certify they meet regulation requirements. However, as time passes more and more materials become available to meet the requirements for building in bushfire prone areas.
This means that there are more choices for how you can build.
DESIGN Your Architecture.
Designing in a bushfire prone area is fascinating!
There is a lot of information to digest that can be confusing and conflicting, but I love that it is nature, art, science and practicality all rolled into one. Use all of the information that you have gathered about bushfire and your place and yourself to find a solution that is right for you.
These are my simple thoughts on designing for bushfire.
Don’t forget to add all the little things you have learned to make your architecture effective in a bushfire. For instance a place to keep the blankets, or buckets, or hose you will use to protect yourself and your home.
The main thing that I want to say here is
think about how you want to use your building
You REALLY need to know the purpose for your architecture in the event of a bushfire.
This will help you design a bushfire strategy for your architecture. It will inform the location of your architecture, the form of your architecture, the configuration of the spaces within your architecture, the materials you will use to construct you architecture.
Do you want to be able to shelter in your home, or will you flee? Do you want to have the ability to fight the fire? Do you want to close shutters on your home before you leave, or have windows that will hold off the fire entering your building?
For instance, ensure to allow space for a fire truck to access your place and park in a position where they can access your water tank to fight a fire. Also, limit the face of your architecture facing the fire source - in other words, limit the surface area of the building that faces down the hill towards where the fire will come.
And this does not just apply to bushfire. The ways that you use your home when a bushfire comes can be applied in different ways to the ways you use your home every day.
For instance, our home will sit on a hill and be located in the highest bushfire level. We will dedicated fire fighting water tanks available for use. We also need a place to park our cars. So on the slope, we will use concrete water tanks, partly in ground and out, to store water to fight a fire, while providing an every day parking space.
That is the first little thing.
The second little thing is that building for a bushfire seems to be a lot about
To be honest, in my experience it does not seem to matter what risk level your place is placed in - if there is ANY risk a fire will reach your home, your priority should be to ensure that if you are caught there, that home can help to protect you.
The materials you use to build your architecture will help to protect you.
So, look at all the options available and choose material products that will best suit you. There are always new ones coming onto the scene, so don’t assume that the ones you looked at six months ago are the only ones available! Take another look and see what has been added since you last gathered information.
The third little thing is to
SEAL YOUR BUILDING
It is commonly believed that a fire in a building will most likely start from the inside. If embers from a bushfire enter your building, they will start a fire there. It can be a tiny ember that travels into your building through a small gap and ignites something inside that begins to burn.
The other way that a bushfire can enter your building is through a material that is easily penetrated - such as glass. Did you know that a heat wave travels ahead of a bushfire? It can be many kilometres in front of the actual fire front. It is VERY hot and when it arrives at your home the heat interacts with the materials of your building. The glass is a lot cooler than the heat wave, so when the difference in temperatures meet, the glass shatters! This creates an opening in the fabric of the building. It is no longer sealed and the embers that are also travelling ahead of the fire front, can enter your building and start to burn.
As such, it is important to protect your architecture, and yourself, by sealing it against the possibility of embers entering. The main places that embers can enter are
at the junction of materials - at joints and corners and edges.
at openings, such as doors and windows - particularly those with glass.
Find ways to make sure that embers cannot get in.
Lastly, a fire fighter I was chatting with, who has lived in the mountains for many years, told me that we live in the mountains for a reason, so
don’t live in a concrete bunker. But design in elements that will help protect you when a fire comes.
‘During a bush fire, loss of basic services such as water and electricity can happen. When constructing your home, it will be necessary to consider how certain services are connected. For example, if your property is not able to be connected to mains water then you may need to consider additional water storage on your property in the way of a pool, water tank or even a dam.’ RURAL FIRE SERVICE
UNDERSTANDING THE ACRONYMS
AS – Australian Standard
‘Australian Standards are published documents setting out specifications and procedures designed to ensure products, services and systems are safe, reliable and consistently perform the way they are intended to. They establish a minimum set of requirements which define quality and safety criteria.’
AS3959 Construction of buildings in bushfire-prone areas
AS1530.1 Methods for fire tests on building materials, components and structures
AS1530.2 Tests on elements of construction for buildings exposed to simulated bushfire attack - Large flaming sources. Includes Compliance for Radiant Heat Transfer
AS1530.3 Simultaneous determination of ignitability, flame propagation, heat release and smoke release
AS1530.4 Fire-resistance tests for elements of construction. Does not include Compliance with Radiant Heat Transfer
APZ – Asset Protection Zone
‘Vegetation around your home allows an easy path for a bush fire to reach your house. Homes with too much vegetation are difficult to defend.
An Asset Protection Zone is an area surrounding your house where vegetation is kept to a minimum. The APZ provides a space between the bush fire threat and your home. The APZ can stop the fire spreading to your home and provide fire fighters a safe area to work.
- An area of continuous vegetation may increase the intensity and severity of a bush fire hazard.
- Reducing the number of trees and shrubs and keeping your lawn short influences the intensity of the bush fire.’
BAL – Bushfire Attack Level
‘The BAL is based on different factors including the type of vegetation, the slope of the land and the distance to the bush. This reflects the potential nature of a bush fire at back to the house and can be in the form of ember attack, radiant heat or flame contact.
Construction requirements do not apply to buildings located more than 100 metres away from the bush’
The Bushfire Attack Levels are currently as follows:
BAL-Low Lowest risk from a potential fire
BAL-12.5 Risk is primarily from potential embers during a fire.
BAL-19 Moderate risk, particularly from embers and burning debris.
BAL-29 High risk, particularly from embers, debris and heat.
BAL-40 Very high risk. Likely to be impacted by embers, debris, heat and potentially flames.
BAL-FZ Extreme risk. Directly exposed to the flames of a potential fire front.
Bush Fire Information Line Call 1800 NSW RFS [1800 679 737]
NSW Rural Fire Service Website www.rfs.nsw.gov.au
Fire Danger Ratings www.rfs.nsw.gov.au/fdr
Free Smartphone App ‘Fires Near Me’
Local Radio Local ABC | Emergency Broadcaster Frequency
AIDER Program email@example.com
The RFS provides an ‘Aider’ program to give assistance to those who are infirm, disabled or elderly. They will come to your home and assist you prepare for a fire.
There is SO much to talk about when discussing design and building for bushfires. I just can’t say enough about it! It is scientific and artistic and interesting and every day.
It is also specific to you.
All the best finding the bushfire solution for your design that is best for you!
Til next time!