California Code of Regulations · Title 24
The California Building Standards Code, explained
The California Building Standards Code (Title 24) is organized into 13 parts — the building, residential, electrical, mechanical, plumbing, energy, fire, green and other codes that govern construction across the state. The 2025 edition is current, effective January 1, 2026.
Pick a part below for a plain-English overview — or ask GoCodebook a question and get the controlling section for your jurisdiction with a citation.
The 13 parts of Title 24
Part 1
California Administrative Code (CAC)
Administrative regulations and procedures that govern how the California Building Standards Code is adopted and enforced.
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California Building Code (CBC)
Structural, fire, accessibility and occupancy requirements for commercial and multifamily buildings.
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California Residential Code (CRC)
Construction standards for one- and two-family dwellings and townhouses up to three stories.
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California Electrical Code (CEC)
Electrical installation, wiring and safety requirements based on the National Electrical Code.
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California Mechanical Code (CMC)
HVAC, ventilation, exhaust and mechanical system requirements.
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California Plumbing Code (CPC)
Plumbing, drainage, venting and water-supply requirements.
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California Energy Code
Energy-efficiency standards for residential and nonresidential buildings (Title 24, Part 6).
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California Wildland-Urban Interface Code (CWUIC)
Fire-resistant construction requirements for buildings in wildfire-prone (WUI) areas.
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California Historical Building Code (CHBC)
Alternative standards that preserve qualified historic buildings while protecting safety.
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California Fire Code (CFC)
Fire prevention, protection systems and life-safety requirements.
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California Existing Building Code (CEBC)
Repair, alteration, addition and change-of-occupancy provisions for existing buildings.
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California Green Building Standards Code (CALGreen) (CALGreen)
Green building, water-efficiency and sustainability requirements.
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California Referenced Standards Code (CRSC)
The referenced standards adopted into and enforced under Title 24.
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