California has long had the strongest defensible space rules in the country. Now, it’s drafting rules that would make it the first state to limit plants directly next to buildings. In areas of high fire risk, plants within five feet of a house are strictly limited.
The new rules are not expected to go well. Many homes have built landscaping along their exterior walls, which homeowners may be reluctant or even refuse to do. State regulators are evaluating whether certain plants are safe to keep in that zone, such as green lawns or mature trees without branches touching the house.
“We understand this is not an easy transition for some homeowners,” said Daniel Berlant, acting state fire marshal with Cal Fire, the state’s firefighting agency. “But the science is simple: even a green, well-maintained plant will catch fire and it will destroy your house.”
Fire experts say it’s all about ignoring the idea of how landscaping should be laid out. Driveways and patios should lead directly to a house, rather than through plants.
With the costs of wildfires skyrocketing, in human toll and dollars, California’s regulators say that communities must do everything they can to reduce the dangers. The upcoming rules could have a broader impact, as many other Western states are following California’s lead on wildfire policy.
Two buildings, two different results
At a large empty airfield in Sacramento, firefighters set fire to two small buildings.
It’s a demonstration, led by the Insurance Institute for Business & Home Safety, a non-profit funded by the insurance industry that studies what makes buildings vulnerable.
Both structures are surrounded by bark mulch, green plants and trees. But there is one key difference: around a building, the mulch and trees are directly next to the walls. On the other side, a stone path separates them, acting as a buffer.
Two small spot fires ignited in the mulch, mimicking a typical ignition of large wildfires where strong winds carry embers ahead of the fire.
“Research shows that the lungs are often the first point of attack,” said Roy Wright, president of the Insurance Institute for Business & Home Safety. “Those lungs can be the size of your thumb or even the palm of your hand and can be up to half a mile long.”
In a demonstration in California, fire experts showed how bark mulch can act as a match. A stone walkway directly next to a building will prevent a wildfire from burning it down. Lauren Sommer/NPR hide caption
toggle caption Lauren Sommer/NPR
The fire quickly spread through the mulch near a building, bringing the flames directly to the walls. The structure eventually burned to the ground. The other building next door came alive. The mulch burned until it hit the stone path where it stopped.
Protected space doesn’t guarantee a home will survive a wildfire, but experts say surrounding exterior walls with hardscape, such as gravel, paths or patios, can reduce the risk.
“The Wildfire adaptation takes on a different aesthetic,” said Anne Cope, chief engineer at the Insurance Institute for Business & Home Safety. “We have to take our beautiful landscaping and our flowers that we enjoy so much as people and we have to move that out of the house where we can see it from the window and still enjoy our gardens, no just next to the structure. .”
Moving plants is a tough sell
With wildfires on the rise in California, lawmakers passed a bill in 2020 to create an “ember-resistant zone” within five feet of a home. Due in part to a warmer, drier climate, wildfires have destroyed nearly 40,000 homes and buildings in the past six years across the state, causing billions of dollars in damage.
Now, state authorities are writing the rules for the five-foot zone, also known as “zone 0.” The state already has rules for creating defensible space within 100 feet of a structure, which requires clearing dead brush and cutting tree limbs. The new rules apply to fire-risk areas outside city limits, as well as to zones with the highest fire risk within cities themselves.
The simplest version of the rules would mandate that no plants be allowed within five feet of a structure, something that would be easier for fire inspectors to enforce. But public acceptance of that will be more than challenging, regulators worry. They are now evaluating what types of plants may be allowed, such as small plants with space between them, green grasses or groundcovers, or mature trees that are sufficiently trimmed from a building.
“Emotionally, it’s a big change for people,” said Frank Bigelow, Cal Fire’s assistant deputy director of Community Wildfire Preparedness & Mitigation. “Most of the people who follow now, don’t follow anymore.”
It was a tough sell for her own parents, Bigelow said.
“When I told them: out in the front yard, where you have the mulch and you have that little tree in front of the window, that all needs to come out,” he said. “And my dad said ‘The heck it is. We paid a lot of money to get that landscaping done. I’m not going to move that.”
The rules were supposed to be finalized by January, but tensions have led to delays. The regulations will first apply to new construction in 2025, where changes can be quickly implemented as homes are built.
“We worked with builders and industry to flip-flop the idea: put the driveway next to the house and put the plants on the other side of the driveway so now you’ve got that five-foot distance,” Berlant said. – said.
For existing homes, the rules will go into effect in 2026. State firefighters say a broad education campaign is needed to help homeowners make the transition. One of the biggest motivations may come from insurance companies. As wildfire damage increased, Californians saw their insurance premiums rise and some companies left the state market entirely. Some now offer discounts to homeowners who create protective space around their homes.
“This is the kind of thing that insurers recognize in terms of reducing risk,” Wright said. “States across the West are following California’s lead.”