San Bernardino County, CA Environmental Rules: Defensible Space (2026)

4291.

(a) A person who owns, leases, controls, operates, or maintains a building or structure in the state responsibility area shall at all times do all of the following:

(1) (A) Maintain defensible space of 100 feet from each side and from the front and rear of the structure, but not beyond the property line, except as provided in subparagraph (B). The amount of fuel modification necessary shall consider the flammability of the structure as affected by building material, building standards, location, and type of vegetation. Fuels shall be maintained and spaced in a condition so that a wildfire would be unlikely to ignite the structure. This subparagraph does not apply to single specimens of trees or other vegetation that are well-pruned and maintained so as to effectively manage fuels and not form a means of rapidly transmitting fire from other nearby vegetation to a structure or from a structure to other nearby vegetation or to interrupt the advance of embers toward a structure. The intensity of fuels management may vary within the 100-foot perimeter of the structure, with more intense fuel reductions being utilized between 5 and 30 feet around the structure, and an ember-resistant zone being required within 5 feet of the structure, based on regulations promulgated by the board, in consultation with the department, to consider the elimination of materials in the ember-resistant zone that would likely be ignited by embers. The regulations may also alter the fuel reduction required between 5 and 30 feet to integrate the ember-resistant zone into the requirements of this section. Consistent with fuels management objectives, steps should be taken to minimize erosion, soil disturbance, and the spread of flammable nonnative grasses and weeds. For purposes of this subparagraph, “fuel” means any combustible material, including petroleum-based products, cultivated landscape plants, grasses, and weeds, and wildland vegetation.

(B) A greater distance than that required under subparagraph (A) may be required by state law, local ordinance, rule, or regulation. Fuel modification beyond the property line may only be required by state law, local ordinance, rule, or regulation in order to maintain 100 feet of defensible space from a structure. Fuel modification on adjacent property shall only be conducted following written consent by the adjacent landowner. Any local ordinance related to fuel modification shall be in compliance with all applicable state laws, regulations, and policies. Any local ordinance may include provisions to allocate costs for any fuel modification beyond the property line.

(C) An insurance company that insures an occupied dwelling or occupied structure may require a greater distance than that required under subparagraph (A) if a fire expert, designated by the director, provides findings that the fuel modification is necessary to significantly reduce the risk of transmission of flame or heat sufficient to ignite the structure, and there is no other feasible mitigation measure possible to reduce the risk of ignition or spread of wildfire to the structure. The greater distance may not be beyond the property line unless allowed by state law, local ordinance, rule, or regulation.

(2) Remove that portion of a tree that extends within 10 feet of the outlet of a chimney or stovepipe.

(3) Maintain a tree, shrub, or other plant adjacent to or overhanging a building free of dead or dying wood.

(4) Maintain the roof of a structure free of leaves, needles, or other vegetative materials.

(5) Before constructing a new building or structure or rebuilding a building or structure damaged by a fire in an area subject to this section, the construction or rebuilding of which requires a building permit, the owner shall obtain a certification from the local building official that the dwelling or structure, as proposed to be built, complies with all applicable state and local building standards, including those described in subdivision (b) of Section 51189 of the Government Code, and shall provide a copy of the certification, upon request, to the insurer providing course of construction insurance coverage for the building or structure. Upon completion of the construction or rebuilding, the owner shall obtain from the local building official a copy of the final inspection report that demonstrates that the dwelling or structure was constructed in compliance with all applicable state and local building standards, including those described in subdivision (b) of Section 51189 of the Government Code, and shall provide a copy of the report, upon request, to the property insurance carrier that insures the dwelling or structure.

(b) A person is not required under this section to manage fuels on land if that person does not have the legal right to manage fuels, nor is a person required to enter upon or to alter property that is owned by any other person without the consent of the owner of the property.

(c) (1) Except as provided in Section 18930 of the Health and Safety Code, the State Fire Marshal may adopt regulations exempting a structure with an exterior constructed entirely of nonflammable materials, or, conditioned upon the contents and composition of the structure, the director may vary the requirements respecting the removing or clearing away of flammable vegetation or other combustible growth with respect to the area surrounding those structures.

(2) An exemption or variance under paragraph (1) shall not apply unless and until the occupant of the structure, or if there is not an occupant, the owner of the structure, files with the State Fire Marshal, in a form as the State Fire Marshal shall prescribe, a written consent to the inspection of the interior and contents of the structure to ascertain whether this section and the regulations adopted under this section are complied with at all times.

(d) The Sta