Defensible Space for Fire Resistance

Defensible space, combined with home fire hardening, can increase the odds of your house or home surviving a fire that comes onto your property. In Los Gatos, a large portion of our town, and neighboring unincorporated communities, falls under areas where homeowners are required to mitigate the wildfire risk by reducing fuel and taking other actions. We’ll look at where those areas are and what homeowners in them are required to do.

1 – Mandatory defensible space areas

Is your property in a mandatory defensible space zone? In Los Gatos, there are two listed types under this umbrella:

You can see if your Los Gatos home is in either of these zones by checking the town’s online map, a smaller version of which is below. Areas in red require defensible space criteria to be met and are in one area or the other.

 

Los Gatos - defensible space zones for fire risk mitigation
Click on image to view map on the town’s website – Los Gatos. Mandatory defensible space zones for fire risk mitigation are in red.

As you can see, many Los Gatos neighborhoods fall into this zone, including much of the Civic Center area, Vista del Monte, Glenridge, and many more.

What about unincorporated areas, or Monte Sereno?

 

Cal Fire map of hazard severity zones

 

The town’s map is fairly busy and does not cover the unincorporated areas, or Monte Sereno. An easier one to zoom in on, and which is agnostic toward town boundaries, is on the Cal Fire site, but you will need to zoom quite a few times to see your area. I find this one much easier to read.

2 – What do you need to do to create defensible space in the high fire risk zones?

Laws regulating what must be done (and what can be done, in the case of additions and new construction) in the higher risk fire areas come from both the town and the state. Both of them aim to get residents to remove fuel, such as dead leaves, needles, plants, firewood, and so on are a major step. Thinning brush out, or thinning lower tree branches so that it’s harder for fire to spread is also key. Spacing trees and bushes away from each other, and especially from the house and chimney of homes in the high fire risk zones is crucial, too. Read on to get lists of what to clear out if your property is in these areas with increased fire risk.

Los Gatos

The Town of Los Gatos has passed Ordinance 2301 to amend the regulations on weed abatement to be more encompassing. Easier to read and follow is the town’s page on being wildfire ready. Please do check out the town’s ordinance page and wildfire ready page. I’ll summarize some key points here but the total story is found with the town.

Think of the requirements below as creating your own fire break to reduce risk of property damage or loss from an inferno.

There are 3 zones identified by the town, with the most restrictive being the closest to your home.

Within 5 feet of the structure it’s called the noncombustible zone. Homeowners are to do a number of things to remove fuel for fires, including

  • Remove all plants and vegetation, especially those touching your home.
  • Clean roofs and gutters of dead leaves, debris and pine needles that could catch embers.
  • Reduce embers that could pass through vents in the eaves by installing 1/8 inch metal mesh screening. (Standard appears to me to be 1/4 inch.)
  • Move any flammable material away from wall exteriors – mulch, flammable plants, leaves and needles, firewood piles – anything that can burn. Remove anything stored underneath decks or porches.
  • Please see the whole list on the town’s website https://www.losgatosca.gov/2581/Be-Wildfire-Ready

The town’s page does not mention it, but the fire hardening disclosure for home sales in these high fire risk zones asks if sellers have metal gutter guards to keep leaves and needles from accumulating in the gutters. It is a good idea to provide that protection, in addition to keeping the gutters cleared of debris.

The next area is within 30 feet of the home, which the town is calling the clean and green zone. The main point is to remove dead or dry vegetation (plants, trees, weeds, pine needles, leaves, etc.), to space trees from your home or other flammable things like patio furniture, to keep tree branches away from your roof and chimney, and so on.

This list is smaller, so I’m including all of it here:

  • Remove all dead plants, grass and weeds (vegetation).
  • Remove dead or dry leaves and pine needles from your yard, roof and rain gutters.
  • Trim trees regularly to keep branches a minimum of 10 feet from other trees.
  • Remove branches that hang over your roof and keep dead branches 10 feet away from your chimney.
  • Create a separation between trees, shrubs and items that could catch fire, such as patio furniture, wood piles, swing sets, etc.

The third zone extends 100 feet out and is called the reduced fuel zone.

In many cases, home owners are not responsible for risks beyond their own property line, but that does not appear to be an absolute. Many of the homes in these areas are not surrounded by 100 feet of their own property before hitting the parcel boundary. If there’s an issue on the other side of the fence or property line, you may want to talk to the local fire marshal about it.

This last zone is more complicated, but includes the general principles above of removing dead leaves, needles, bushes, to eliminate unnecessary fuel for a fire. Additionally, there needs to be horizontal space between trees and their canopies. Small conifers between mature ones should be removed. Trees should be trimmed so that there is some vertical clearance, too. More rules applies when there are slopes. Please read and study the town’s wildfire ready page (linked above) for all of the details.

CAL Fire requirements for defensible space (similar but not the same)

CAL Fire has a checklist, dated March 2017, for inspections. It’s called the NOTICE OF DEFENSIBLE SPACE INSPECTION, and it is a good list if you want to know where to get started. This is now 4 years old and if the town’s list is more stringent, of course follow that, but this is very clear and mentions some things a little more plainly. If I can find a newer list from CAL Fire, I’ll share that in the future.

For this list, Zone 1 is up to 30 feet either from the structure OR the property line, as opposed to the town’s 5 feet for Zone 1. In some ways it’s more restrictive, but others more liberal.

CAL Fire’s sheet on defensible space states that home owners should “Relocate exposed wood piles outside of Zone 1 unless completely covered in a fire resistive material, pursuant to 14 CCR § 1299.03(a)(3).”  For the town, there should not be any wood piles within 5 feet of the home at all, but between 5 feet and 30 feet, the piles should be located so that they are spaced with an undisclosed amount of separation from things that might burn (think fences, patio furniture, decks).

Some backyards in town are just 20′ deep, so if there’s firewood to be stored in that zone, it doesn’t seem like there’s a solution in such cases since it seems it would need to be 30 feet or more from the house, but should not be up against the fence, either.

Changing level of concern and questions around wildfires

In response to the larger numbers and sizes of the fires, the state, the counties, and local cities and towns are all having to address the increased fire risk. Buildings have become more fire resistant since about 2010, and that helps. Homes built before that likely need to have some fire hardening retrofits.

I would expect to see a cottage industry emerge of specialists who can both do the fire hardening work and also sort out the various rules for what needs to be done in terms of defensible space. Low water use, lower fire risk plantings may become popular, while more flammable plants and trees (think eucalyptus) may become pariahs.

As of July 1, there are new laws in California regarding home construction in high fire risk areas. We are hearing trickles of information about them, but one concern is whether homes can be built on streets with only one way in or one way out. (I believe this is only for high fire severity risk zones.) Apparently the fire department wants two access points. Do fire roads count as an access point? I can think of fire roads, such as between Harwood Court and Santa Rosa in east Los Gatos, and I wonder if that counts as 2 access points or not since the gates are locked – great for fire trucks to get in but not so good for people in autos who may need to escape.

(Side note: the state is encouraging the addition of accessory dwelling units, or ADUs, and a Los Gatos official I spoke with earlier today said that they are looking into these building issues, but stated that ADU construction would be exempt, if someone wanted to add one. At least that is the status as of today.)

What we are not seeing much of is controlled burns to keep the fires from becoming mega fires. We have a very small number of them – I don’t know why that is the case. My editorial two cents is that prevention is key, and a comprehensive fire plan to prevent disaster might also consider controlled burns as part of the formula.