Fire Safe, Fire Resistive, Fire Proof, What Does It All Mean?
I sit here breathing our smokey air and continuing to count my lucky stars that our local Cal-Fire folks have been doing an extraordinary job of putting out local fires. As I meet with clients, the subject of how to make their new homes as safe from wildfires as possible always comes up. Is it really possible to make your new home completely fire safe?
I suppose it would be possible but it’s not likely to be the home you want to live in the rest of the time. Most of us want to be safe but still enjoy the beautiful environment around us. Sure, a concrete structure with steel shutters over few openings would be likely to survive almost anything. Underground homes with limited glazing and roll down storm covers might work but they have their own disadvantages. Given most clients desire for big windows and expansive connections to the outdoors, what can we do?
Here in the California Foothills and Sierra, we are considered to be in the Wildland Urban Interface area and the codes dictate that we incorporate many features which are intended to lessen the chance of your home burning during a wildfire event. We don’t yet have enough data to know how effective these measures are but they certainly seem like they should provide some protection. History shows us that the most effective measures are probably well maintained defensible space, a non-combustible roof, and good driveway access. Additional requirements are ignition resistant exterior materials, tempered glazing in windows, limited, screened or protected vent openings, protection on the underside of eaves, gutter covers and good driveway access among other things.
Are there other things we can do beyond those required by code? Of course, there are. You can select exterior materials that exceed the requirements of the Wildland Urban Interface regulations. Instead of ignition resistant materials you and your designer can select non-combustible products like metal roofs, stone, stucco or cement based sidings, double tempered glazing in your windows and patios or decks with concrete or tile surfacing. You can also consider roof & crawlspace designs that eliminate or severely restrict ventilation openings. All of these techniques have pluses and minuses but if you are building in a forest area or on the edge of town, they are all things that should be at least considered.
In my opinion, the most effective thing you can do is maintain your defensible space. This can be tricky when you don’t own all of the land between your home and the recommended 30′ and 100′ clearance zones but cooperating with your neighbors to create defensible space between your homes and locating your home carefully can go along ways to making your home more likely to survive a wildfire. California requires that new homes be built a minimum of 30′ from a property line in wildfire vulnerable areas but that’s not always possible. The regulations do provide for the mitigations such as non-combustible finishes, limited glazing or other measures that may provide the same practical effect.
I would also encourage you to limit raised decks if your property allows for on grade patios or using a non-combustible deck surface if your budget allows. One benefit of fire safe design choices is that they are also likely to be lower maintenance options. And there are even alternative, sustainable material choices that could make sense like David Easton’s Watershed Block.
Other things to consider are where to store firewood, the location of propane tanks, on-site water storage and locations of detached sheds.
Like everything else in building design, the selection of features and materials to minimize the risk from wildfire is always a compromise between function, cost, and livability but talking about your goals with your designer is the first step. It sometimes feels like all the requirements are just more bureaucracy to deal with and there’s nothing you can do to truly ensure that your home will survive a wildfire, these are issues worthy of your consideration.
The following are articles that may make for interesting reading: