California Building Code 2025 is a professional guide to Title 24, Part 2, written for architects, engineers, contractors, inspectors, designers, and advanced students who already understand the basic logic of the 2024 International Building Code. The book focuses on the California Delta: the points where California amendments, agency authority, wildfire exposure, seismic conditions, and inspection practice change the assumptions commonly brought from IBC-based work. Topics include: Title 24 structure, state amendments, local amendments, and legal hierarchy Agency jurisdiction involving the State Fire Marshal, HCD, DSA, HCAI/OSHPD, and local AHJs Occupancy classification, mixed uses, fire areas, and control areas Chapter 7A, WUI requirements, ember intrusion, roofs, vents, eaves, walls, and balconies Seismic Design Categories D, E, and F, including nonstructural anchorage and MEP bracing Fire-resistive assemblies, shafts, penetrations, joints, and firestopping Means of egress, sprinklers, alarms, emergency power, and acceptance testing Special inspections, field deviations, stop-work risks, and corrective work Rather than reproducing the code, Manfred Bauer explains how requirements affect real assemblies, review pathways, coordination, sequencing, documentation, and field inspection. The book concludes with practical guidance for podium buildings, multi-agency projects, phased occupancy, WUI coordination, seismic restraint, and common California rejection triggers.