Preparing Homes for Wildfire: Property Upgrades Across Neighborhoods Can Prevent Fire Losses
The Outthink Wildfire™ policy initiative from NFPA® is a bold call to action and a challenge to end the destruction of communities by wildfire. It’s a comprehensive push to address one of the gnarliest challenges we face in the fire safety arena.
The gnarl factor is heightened by the fact that there are already 45 million existing US homes at risk of burning to the ground due to wildfires. At a recent policy summit, more than two dozen experts discussed what it would take to upgrade these homes to be more ignition-resistant and to improve their chances of survival. Phrases like “retrofit” and “home hardening” were used, but in the face of ever-growing wildfire threats, some may wonder if a home improvement strategy could truly be effective in stopping the trend of multi-billion-dollar disasters involving thousands of homes in a single incident.
While home improvements alone will not solve the problem, individual home retrofits across neighborhoods, and scaled up across regions, can absolutely make a difference. Sixty-plus years of research, experiments, and analysis give us the confidence to say that what people do to their homes and immediate surroundings can indeed improve fire-resistance and structure survival in the face of wildfire, as described in detail by the University of California Cooperative Extension Forestry.
Many of these structural improvements are simple and inexpensive, on the order of regular home maintenance. Others involve a large but infrequent investment that will pay off over time, such as roof and window replacements. The key activities appear on the NFPA preparedness checklists, in NFPA standards, in some state and local regulations, and in the new Wildfire Prepared Home designation from the Insurance Institute for Business & Home Safety (IBHS). These standards and guidelines all derive from what fire safety advocates have learned from the research community over decades.
What do we know about how homes burn in wildfire events?
We know that burning vegetation can ignite homes in three ways: radiating heat to the structure, flames touching the structure, and burning or smoldering embers piling up on or entering the structure through openings. These three mechanisms of fire spread can all happen at the same time.
The most notorious culprits in home ignition from burning vegetation are embers, also known as firebrands. These pieces of burning material pile up on roofs, in gutters, and on flat surfaces like decks. They are driven by the wind into any openings in a home, including chimneys, vents, windows, pet doors, and in the cracks under doors. They can also burn mulch and shrubs up close to the home that then ignite the structure.
Homes can also ignite if any flames touch the house, porch, deck, fence, and any other structural attachments. Imagine a dry lawn or a bed of pine needles providing a continuous path for flames to travel to the vulnerable parts of your structures. Finally, if there is enough dense vegetation within 30 feet (9 meters) of a structure, it can potentially radiate enough heat to ignite the walls.
But for all the damage that burning vegetation can do to homes, it’s our own human-made fuel packages, in the form of vehicles, firewood piles, outbuildings, and our homes themselves that present some of the greatest dangers and can result in the destruction of whole neighborhoods. Once the wildfire burning through the vegetation ignites one of these fuel packages, it’s arguably no longer a wildfire. It’s a conflagration where these elements burn for a long time and ignite nearby homes through radiant heat or by generating flames that touch other houses or by casting off embers that go on to ignite neighboring properties.
What can we do to prepare homes for wildfires?
There are a number of steps homeowners can take to prepare.
1. Operate under a worst-case scenario. Assume firefighters cannot respond with personnel, vehicles, and water to protect your home. Keep in mind that your home safety upgrades are for when a wildfire is approaching, and you and your family have evacuated. Retrofits should be aimed at preventing the wildfire or surrounding structures from igniting your home.
2. Minimize ignition to your home’s exterior with roof repairs or replacements, dual- or triple-paned windows, and screened vents and openings. Repair any cracks in shingles or siding, and remove ignitable material from decks and patios during times of high wildfire danger.
3. Address the area within 5 feet (1.5 meters) of your home’s perimeter and ensure there is nothing there that can burn—mulch, shrub, wood piles, wooden attachments, and so on.
4. Keep large fuel packages like firewood piles or vehicles 30 feet (9 meters) or more from homes at times of high fire danger.
5. Reduce the ignitability of your yard or acreage within 30 feet (9 meters) of your home and out to your property line by landscaping with fire in mind.
6. Work with your neighbors to reduce ignitable elements on your shared boundaries and encourage them to work with their other neighbors.
These tips and more can be found on the NFPA website. As advocates for improving policy to incentivize and support home and community fire safety, NFPA and like-minded organizations continue to seek ways to accelerate the pace of home and neighborhood upgrades so we can end wildfire disasters.