What is Title 24?

California Title 24, officially known as the California Building Energy Efficiency Standards, is a set of regulations that establish minimum energy efficiency requirements for new construction and certain building alterations in California.

Overview

Title 24, Part 6 of the California Code of Regulations is administered by the California Energy Commission (CEC) and sets forth energy efficiency standards for residential and non-residential buildings. These standards are updated every three years to incorporate the latest in energy efficiency technology and building science.

History and Purpose

Title 24 was established in 1978 in response to the energy crisis of the 1970s. California was the first state in the nation to establish energy efficiency standards for buildings. Since then, these standards have been continuously updated and strengthened.

Key Objectives:

• Reduce energy consumption in California buildings
• Decrease greenhouse gas emissions and combat climate change
• Reduce peak electricity demand
• Improve indoor environmental quality
• Promote renewable energy adoption
• Achieve cost-effective energy savings for building owners

Who Must Comply?

Title 24 compliance is required for:

• All new construction (residential and commercial)
• Additions to existing buildings
• Alterations that affect building systems (HVAC, lighting, envelope)
• Tenant improvements in commercial buildings

Building Types Covered

Residential Buildings (CBECC-Res)

• Single-family homes
• Multifamily buildings (apartments, condos) up to three stories
• Townhouses
• Manufactured homes

Non-Residential Buildings (CBECC-Com)

• Office buildings
• Retail stores
• Schools and universities
• Hotels and motels
• Hospitals and healthcare facilities
• Restaurants
• Warehouses
• High-rise multifamily (four stories or more)

Key Components

1. Mandatory Measures

All projects must comply with mandatory requirements including:

• Minimum equipment efficiency levels
• Insulation requirements
• Air sealing and duct testing
• Lighting controls
• Water heating efficiency

2. Prescriptive Requirements

A simplified compliance path where buildings meet specific requirements for each component (walls, windows, HVAC, etc.) based on prescriptive tables.

3. Performance Approach

A flexible compliance path where the proposed building's energy use is compared to a standard reference design. This allows trade-offs between different building components.

Climate Zones

California is divided into 16 climate zones, each with specific requirements based on local weather patterns, temperatures, and solar conditions. Climate zones range from:

• Zone 1: Arcata (cool coastal)
• Zone 6: Los Angeles (warm coastal)
• Zone 12: Sacramento (central valley)
• Zone 14: China Lake (desert)
• Zone 16: Mount Shasta (mountain)

Compliance Documentation

To demonstrate compliance, the following documents are typically required:

• CF-1R (Residential) or CF-1R-ENV/MCH/PLB (Residential): Certificate of Compliance
• CF-2R: Certificate of Installation
• CF-3R: Certificate of Verification
• Energy Analysis Report: Detailed calculations and modeling results

2026 Standards

The 2025 Title 24 standards (effective January 1, 2026) include significant updates:

• Expanded heat pump requirements for space and water heating
• Enhanced battery storage provisions and solar integration
• Improved indoor air quality and ventilation standards
• Updated building envelope requirements
• Stricter lighting efficiency requirements

Additional Resources

• California Energy Commission - Title 24 Homepage
• Title 24 Compliance Guide
• Frequently Asked Questions