building a fire resistant house...

When we homesteaded a piece of raw land in one of the most extreme Chaparral wildfire danger zones in the US...

(view from house)


...we decided to build fire insurance into our house instead of paying expensive fire insurance premiums for the rest of our lives. I read about and watched videos of wildfires burning houses so as to better understand the reasons, and discovered that more houses burn down from embers than the actual fire front. There are two basic processes. Outside in, and inside out.

Outside in is when the land around the house is not properly cleared so that there are "fuel ladders" for the fire to climb onto the house. Fire typically licks up the fuel ladders at the sides of the house and catches the eaves on fire from underneath. Outside in is also when embers fall onto the roof and rain gutters and there is enough debris from overhanging tree limbs to start a roof fire.

Inside out is then embers blow into the house through attic vents and set the house on fire from the inside.

We decided the simplest approach was to design a house that lacked features most vulnerable to fire.



Our design has no attic so there are no attic vents for embers to enter. There are two roofs. The top one is tile while the bottom one is silicone rolled roofing, neither of which are combustable. All the trees are cleared away so that not one leaf can fall onto the roof and gutters. This also offered another side benefit. In 17 years we have never had to clean out a rain gutter.

Our house also has no eaves to catch fire, and no wood fascia, or wood siding, or wood frame windows, or wood steps, or wood decks or wood fencing. All of the outside surfaces are either tile, stucco, glass, or aluminum. The outside entry steps are all poured concrete as is the raised concrete foundation. The result is a highly fire resistant easily defensible house.

I dug out a 12' x 24' basement with a jackhammer so we have a safe place to hole up while the flame front burns through. After it passes through we can put out the remaining spot fires.

I have a few of these kicking around just in case a fire breaks loose. They come in handy for other things too, like making swales of moving logs for a WOFATI, and yes, Katie can run them too. :-)

Our home is made of steel.  It was originally a 'kit' structure marketed as an airplane hangar. On a concrete foundation and I assembled it myself. The exterior walls and roof are steel with a baked on enamel finish.

I sprayed 2 inches of urethane foam on the interior and then hung 9 inches of fiberglass batting, before installing wood grain paneling.

Burning forest trees can fall and land directly on our house, without causing our house to catch on fire.

I think that we need to build more hurricane-proof and wildfire-proof houses.
I don't even think it will cost that much more to build.

https://permies.com/t/38567/Fire-Resistant-Landscaping
https://permies.com/t/75841/Forest-Fire-protect
https://permies.com/t/24169/Wildfires-permaculture

This is something I am also very concerned about.  The forest fires in Northern Ontario made for some fairly tense times last summer.  For a while the main highway to get through central Ontario was shut due to the danger.  When we visited the town closest to our land last, we asked one local what it had been like.  Water bombers were picking up water in the lake, to take to the fire.  Ash was falling on the town like snow.  Constant haze of smoke during the day, and the eerie glow on the horizon at night.  We were very lucky it didn't come any closer.  In the North where logging is a main economical driver, large patches are left scoured.  Walking there feels like being on another planet.  They leave giant slash piles, which might sit several years before the company returns to burn them during the winter.  I wish I had a better picture of the slash piles, they stand out so massively in my mind.

We first wanted to build down instead of up, but it doesn't seem feasible where we are.  After researching here on permies and seeing lots of great information, I also searched youtube and watched some educational videos.  We will also have no attic space, and any vents will be covered with metal mesh to prevent spark intrusion.  Because we will have no basement, the crawlspace will be fully enclosed with brick or stone.  We will side and roof entirely in metal.  We will have storm shutters to close over windows during a fire (I watched some video from the Fort McMurray fire and saw the windows break from the heat, then flames come in through the windows).  A fire break around the house with gravel, and then removing all fire ladders beyond that for a good distance.  A water tank filled by a ram pump from the creek, to a gravity-feed sprinkler system.  Things that one person might find desirable in some cases (exposed wood surfaces, a lot of plantings close to the home), are literally a risk to your life in the circumstances we face in fire prone areas.  I have not watched the video shot by Greg Wilcox, who survived the Camp Fire and unfortunately came across his dead friends after spending several hours in a creek, but it is that deadly serious to have a good plan and protect yourself.

S Bengi wrote:... I don't even think it will cost that much more to build.

When I was pricing these things [2005] a steel structure is much less expensive [per square-foot] than the same size wood-stick structure.

Steel structures are 'hurricane-proof' and pretty much fire-proof.

Galen Young wrote:Burning forest trees can fall and land directly on our house, without causing our house to catch on fire.

Forest trees are a game changer, especially Conifers. We're surrounded by Oaks which don't burn as hot, and we keep them trimmed so nothing can fall onto the house.

S Bengi wrote:I think that we need to build more hurricane-proof and wildfire-proof houses.
I don't even think it will cost that much more to build.

You're totally right.  Every location has its own inherent dangers, so it's not all that difficult to keep them in mind when you design a house.

By doing as much as we could ourselves and paying cash to everyone we hired, our building cost came to about $120 per square foot including the $30,000 building permit.

I really like something called Steel Insulated Panels which I think really have their place. Here, even a mile or so from me, a sawmill produces structural insulated panels, but instead of using steel, they use wood sheathing. I always thought that was kind of silly. Why put sheathing on a insulated panel, only to have to protect it with siding, and then try to keep it from rotting? If a person is going to buy sheathing, why not just install steel and be done; it provides incredible rigidity to the structure and would meet sheathing strengths.

Myself, I have sawmills so producing my own lumber is a way for me to really reduce my costs, but my buildings are not exactly fire proof. Land clearing and my sheep really help drive the forest back though, reducing the likelihood of fire. So does living in a very humid state despite being the most heavily forested state in the nation. Forest fires just do not happen here on any grand scale. The forest service does however keep a list of people with big bulldozers on file that in case of a fire, they can call up to bring in to help snuff out a forest fire.

Where I live, wind is far more damaging then anything else. I live close to the coast and on a big hill so we get slammed by the wind; enough so that on a windy day like today, where it is snowing and blowing 40 mile per hour gale winds, the walls buffet from the wind hitting them. We have thought about building a WOFATI in a few years when the kids leave the nest, as going underground, and getting away from the !@#$%^&* wind, sounds really nice....especially today!

Greg...here a building permit for a new home is $50. A building permit to add onto an existing home is $20.

Travis Johnson wrote:I really like something called Steel Insulated Panels which I think really have their place. Here, even a mile or so from me, a sawmill produces structural insulated panels, but instead of using steel, they use wood sheathing. I always thought that was kind of silly. Why put sheathing on a insulated panel, only to have to protect it with siding, and then try to keep it from rotting? If a person is going to buy sheathing, why not just install steel and be done; it provides incredible rigidity to the structure and would meet sheathing strengths.

That is odd, Travis. If they're replacing wood with steel why not go all the way? We live at ground zero for earthquakes so houses are all shear paneled and foundation anchored. If you could turn our house upside down it would hang from the foundation like a bat! (lol)

Myself, I have sawmills so producing my own lumber is a way for me to really reduce my costs, but my buildings are not exactly fire proof. Land clearing and my sheep really help drive the forest back though, reducing the likelihood of fire. So does living in a very humid state despite being the most heavily forested state in the nation. Forest fires just do not happen here on any grand scale. The forest service does however keep a list of people with big bulldozers on file that in case of a fire, they can call up to bring in to help snuff out a forest fire.

No house is. The best anyone can do is fire resistant. Your area is likely less prone to burn because you get rain. Here it's drought. Historically, California has had droughts lasting as long as 100 years there is nothing to keep this one from lasting a century. We live on the border of 10,000 acres of open land and the Oak tree die off is amazing. Whole areas that have become dead zones. Add to that no management is allowed because of environmentalists, and you have a receipe for disaster. It's forbidden to cut an Oak limb over 3 inches in diameter. You can be prosecuted and heavily fined if you are caught doing it.

Were next to Malibu so the Woolsey Fire burned within a few miles of us.

Greg...here a building permit for a new home is $50. A building permit to add onto an existing home is $20.

We built in an area where no one had built a house since the 1970's. One reason is because it's so difficult and expensive to obtain a permit. The earthquake, fire, seismic and septic building codes here are some of the most stringent in the nation. It took two and a half years to get the plans stamped. Just like Jesus, our application was denied three times. (lol)  At only $30,000 we got off cheap. It's not uncommon for building permits to run into six figures.

Just to be clear, this is not a complaint. We count ourselves blessed to live where we are.



We can walk out our front door and hike to the Pacific Ocean all on open land.



We're close to family and my small businesses are well established in our village.

You are UNDERSTANDABLY confused due to my poor wording, so let me explain better.

Structural Insulated Panels are quite different then STEEL Insulated Panels.

Structural insulated panels are all wood consrtuction. They have oriented strand board sheathing, then stryrofoam insulation, studs, and then drywall on the inside. They are just big, thick panels that have high R-levels for our cold here. Steel insulated panels, most are for industrial use, and use steel, insulation then steel again on the inside, mostly for refrigerated buildings, but increasing, for high r buildings, and now residences. I have to thank Pearl Sutton for turning me on to them.

Steel is a love/hate relationship for me. I love steel roofing because, as you mentioned, it is great for embers from such things as forest fires, but also chimney fires, from igniting the roof on fire. It also makes a structure last forever. Look at any old building, derelict and surviving, and most likely it has a stel roof where it has shed rain and snow despite years of neglect. You don't get that with asphalt shingles! But when my parents house caught fire, the fire depratment could not really fight the fire because that same steel kept the heat contained, and water from being lobbed onto the fire; all it did was cool the steel roofing and run off.

But whether they should be used or not, I LOVE the fact that they can be easily homemade and have high strength.

I have used steel everywhere, inside my barn so the manure can be easily scraped out and not hang up on the sides, on roofs of course, but also as wainscoating inside a half-bathroom. It sure makes cleanup easy if someone gos in there and gets the scatter-turds! I ran my steel sheets vertically, and I think it looks the best, but if I did it again, I would run them horizontally to be sure my outlets always landed in a flat portion of steel. I had one outlet run into a raised portion of the steel panel, and it was a tough issue to deal with.

Ah, thanks for the clarification, Travis. I understand now.

I also like steel for roofs because it's practical inexpensive lightweight and fireproof. I built a simple 22' x 22' carport with a galvanized sheet metal roof to protect our vehicles from embers.