Fuel modification reduces the radiant and convective heat, and provides valuable defensible space for firefighters to make an effective stand against an approaching fire front. Fuel modification zones are strategically placed as a buffer to open space, or areas of natural vegetation, and generally would occur surrounding the perimeter of a subdivision, commercial development, or isolated development of a single-family dwelling.

The Forestry Division’s Fuel Modification Unit provides guidelines and reviews the landscape and irrigation plans submitted by the property owner for approval before construction or remodeling of a structure. Several aspects are reviewed in the plan approval process:  fire history, the amount and type of vegetation, the arrangement of this vegetation, topography, local weather patterns, and construction, design and placement of structures. Our objective is to create the Defensible Space necessary for effective fire protection in newly constructed and/or remodeled homes within the Department’s Very High Fire Hazard Severity Zones (VHFHSZ).


THE FUEL MODIFICATION PLAN identifies specific zones within a property which are subject to fuel modification. These consist of concentric circles designed to create a defensible space buffer around structures; Zones A, B and C are typically outward from the structure 20, 80 and 100 feet, respectively.   Each of these zones has allowable plant types and arrangements; generally speaking, the smaller and greener a plant, the closer to the structure it may be planted.

Fuel Modification Consultants and Expediter List

The following are Fuel Modification Consultants that have previously completed Fuel Modification Plans. The actual services provided may vary by individual company. Not all companies may provide Landscape Plan services.

The Fuel Modification Unit is headquartered at 605 N. Angeleno Ave. in Azusa. Office hours are 8 a.m. to 4 p.m. Monday through Thursday for plan submittal and general questions. Plan checkers are available by appointment only. The Fuel Modification Unit may be reached at 626-969-5205.

Contact – Forestry Division