Building In a Fire Zone

Building In a Fire Zone

building in a fire zone

A. Caluen

This will be the last of these for a while, as I have to go and dig into the next round of research.  However, I would welcome any questions from others considering buying-to-build in California, because I love doing research and, believe it or not, I don't want to just talk about myself all the time.

The Burn Zone

Our lot was threatened by the recent Butte Fire.  All along our road, there are burned-out houses, scorched trees, and in some places - where the fire lingered - piles of ash.  There are a lot of service professionals at work up there now, since over 400 homes were lost in Calaveras and Amador counties.  We didn't have a house to lose, but we were still lucky.

How does this affect our planning?

We go back to the drawing board - literally.  The fire was still burning when I pulled out my house plan to do a redesign.

Our visit in April prompted the biggest part of the redesign, as Mr. P's idea for orienting the house was better than mine.  We have chosen the building site.  My original footprint stays, it's just turned 90 degrees counterclockwise.

My building specs already took into account the "wildland-urban interface" - there is actually a whole supplemental code.  We have to do more specific measurements in order to be certain that our site fits the parameters.  (At most, this will affect the excavation for the foundation; it won't preclude our build.)  

And we have to be more specific about materials, and even more specific about the landscape.  The defensible-space guideline is: brush cleared to 100 feet from the house, or to property line.  Plantings within 30 feet of the house need to be well-maintained, and ideally discontinuous.  This means no pitchy juniper foundation shrubbery, y'all, and no pampas grass.

Turns out there are certain native plants that are recommended for installation near houses in fire zones.  And there are native nurseries where you can buy these helpful things.  I am not likely to find them at Home Depot or Lowe's.

In case you're wondering, all of California is a fire zone except maaayyyybe Humboldt County.  In fact, if you haven't been paying attention, heads up: all of the rural western United States is a fire zone, with the possible exception of coastal Alaska, Washington, and Oregon.

My early pie-in-the-sky gardening schemes went a certain direction.  But I have done a lot of reading over the summer and my schemes are redirected.  I now know of several California-native plants that are classified as fire-retardant.  

That doesn't mean they will stop fires, or that they won't burn; it just means they will help slow the fire down so you can defend your house.  This is a GOOD THING.

And because they are natives, during all the vast majority of the time when there is no fire, these plants will attract native bugs, which will attract native birds and small animals, which will attract native predators, and I will watch a whole lot less TV.

The House Itself

The basics of a fire-resistant house are, well, pretty basic.  You can now get all of the following for a very small premium over conventional building materials:

  • fire-retardant OSB sheathing
  • fire-retardant drywall
  • fire-retardant house wrap
  • fire-retardant insulation
  • fire-resistant siding
  • fire-resistant decking
  • fire-resistant roofing.

By the time we are ready to build, there will be more and better options.

Why would anyone building in a fire zone put wood decking, vinyl siding, and asphalt shingles on their house?  

I submit that it is because most people don't think these things through before the moment when they have to make a decision.  

Think about it before you need it.  Find out what your options are. And ... put it in your budget!  

Our decking is going to be ceramic tile, not cedar as originally imagined.  Our siding and roofing, and the railing for our deck, were always going to be metal.  Our windows are going to be aluminum-framed, and we are going to make fire shutters for all of them.  (This means somewhat fewer windows.  I will trade slightly less natural light indoors for easier prep-the-house-for-evacuation.)

And boy, those fire shutters - ouch.  You will pay roughly $1000 per window to buy commercial fire shutters; and if you are on short notice and desperate and this is the only price you see, it's little wonder if you just take your chances.

But you can make fire shutters yourself* for a few bucks each.  Now, they won't be automatic; you will actually have to hang them up; but consider this: a wildfire is most likely to get into your house by a) sparking through a soffit vent; b) sparking through a gable or ridge vent; or c) breaking a window.  Yes, fire will break your windows.

We saw plenty of lots in the fire coverage where trees were only somewhat scorched, but the house was burned to the ground.  Fire is very domestic - it loves houses.  You have to keep that bitch out.

*DIY fire shutter: cut a sheet of 1/4 inch plywood, large enough to overlap window by min. 6" on all sides; affix metal siding (cheap corrugated steel, same as our siding and roofing, is what I'm planning to use) to one side using short metal bolts.  The plywood is to give the panel rigidity and to slow heat transfer, but one could do this with just a sheet of the metal.  Either way, handle with leather gloves.

Mount heavy-duty screw hooks on the exterior wall above the window, and screw eyes below.  Attach screw eyes to the "top" of your Keep Fire Out panel, and cabinet hooks to the bottom.  To put them up, lift the panel (metal side out) and loop the top eyes over the top hooks; swing the bottom hooks into the bottom eyes.

Is this a rednecky kind of kludge?  Will it be perfect? Yes and no.  But it is a helluva lot better than nothing.

And if you have clear space around your house and gravel out to the dripline of your roof, the fire will not be swirling against your walls chewing through your delicious, flammable foundation plantings until it breaks your windows.  It will, with a little luck, bang on the wall and say "damn it all" and move on.

For more information on making your home more fire safe, check out 

For more information on native plants that meet FireWise guidelines in California, visit the California Native Plant Society page. 

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