Three zones around your home
CAL FIRE frames defensible space as concentric zones. Zone 0 is the "ember-resistant zone," the first 5 feet around a structure. Zone 1 extends from 5 to 30 feet, and Zone 2 reaches from 30 to 100 feet (or to the property line). California law (PRC 4291) generally requires 100 feet of defensible space in wildfire-prone areas.
Each zone has a different job: the closest zone protects the building from embers, while the outer zones slow and shrink an approaching fire.
Where goats do the most good
Grazing is most useful in the outer defensible-space zone (roughly 30–100 feet) and on the wider landscape beyond it, where the goal is reducing brush, weeds, and grass across larger, often steep or rugged areas. This is exactly the terrain where mowers struggle and hand crews are slow.
Closer to the house — especially the ember-resistant first five feet — grazing is not the tool; that zone calls for hardscape and careful, minimal vegetation.
Grazing plus the rest of the plan
Think of goats as an efficient way to handle the bulk vegetation in the outer zones, then finish the detailed work near the structure by hand. Used that way, grazing slots neatly into the official defensible-space framework rather than replacing it.
Always follow your local fire authority’s specific requirements — they can be stricter than the statewide baseline.