CRC Chapter 7A / R327 governs construction in California State Responsibility Areas (SRA) and Marin Local Responsibility Areas (LRA-VHFHSZ). Most of Marin County is mapped as Very High Fire Hazard Severity Zone. Requirements: Class A roof assembly, non-combustible or ignition-resistant siding, dual-pane tempered glazing within 10 ft of grade, 1/8 inch mesh ember-resistant vents, fully enclosed eaves. Defensible space (PRC 4291) extends 100 ft.