Defensible space in California: Zones 0, 1 and 2 explained

Defensible space is the buffer you keep between your home and the vegetation around it. California law (Public Resources Code section 4291) requires it on most parcels in the State Responsibility Area and in local Very High zones, and CAL FIRE describes it as three rings measured from the exterior walls, decks and attached structures.

Zone 0: the first five feet

This is the ember-resistant zone, and it is where most homes are lost. Embers land, ignite something flammable against the wall, and the fire walks into the house through a vent, a window or the eaves.

The aim is nothing that can burn within five feet of the building:

• Replace bark mulch and wood chips with gravel, pavers or bare soil.
• Move firewood, lumber and propane tanks out of the zone.
• Remove shrubs and dead plants against the house. Keep anything that stays well watered and clear of the siding.
• Clear leaves and needles from the roof, gutters and under decks.
• Keep combustible fences and gates from touching the house, or replace the last five feet with metal.

State regulators have been phasing in formal Zone 0 rules. Check CAL FIRE for the current requirement in your area, but the practice above is what the rules are built on.

Zone 1: five to thirty feet

The lean, clean and green zone. Plants can stay, but they should be spaced, maintained and unable to carry fire to the house.

• Remove all dead plants, grass and weeds.
• Clear dead leaves and needles from the yard, roof and gutters.
• Trim trees so branches are at least ten feet from other trees and from the chimney.
• Keep branches away from the roof.
• Relocate wood piles to Zone 2.
• Keep ladder fuels out: no shrubs under trees that would let a ground fire climb into the canopy.

Zone 2: thirty to one hundred feet

The reduced fuel zone, out to 100 feet or your property line, whichever comes first.

• Cut annual grass to a maximum of four inches.
• Create horizontal space between shrubs and trees. On a slope the spacing grows with the gradient.
• Create vertical space between grass, shrubs and the lowest tree branches.
• Remove fallen leaves, needles, twigs, bark, cones and small branches, although a thin layer can be left to control erosion.

Doing the work in the right order

Start at the house and work outward. A perfect Zone 2 with a bark bed against the siding does very little. Zone 0 first, Zone 1 next, Zone 2 last, and then keep each one up every spring before fire season.

Our wildfire assessment draws these three rings to scale around your actual building footprint from aerial imagery, so you can see which parts of the yard fall in which zone before you pick up a saw.

Where an engineered system fits

Defensible space is the foundation. An exterior wildfire defense system such as Embers EPS is built on top of it, not instead of it: it wets the structure and a perimeter line once a fire approaches and after you have left. It is designed for the hours when nobody is home.

Whatever you install, leave when you are told to. No vegetation plan and no system replaces evacuation.