Building Energy Code and Solar Requirement

June 18, 2023


Much of the information presented in this summary is drawn from the U.S. Department of Energy’s (DOE) Building Energy Codes Program and the Building Codes Assistance Project (BCAP). For more detailed information about building energy codes, visit the DOE and BCAP websites.

The California Building Standards Commission (BSC) is responsible for administering California's building standards adoption, publication, and implementation. Since 1989, the BSC has published triennial editions of the code, commonly referred to as Title 24, in its entirety every three years. On July 17, 2008 the BSC unanimously approved the nation's first statewide voluntary green building code. In January 2010, the BSC adopted a final version of the new green building code, CALGreen, parts of which became mandatory on January 1, 2011. CALGreen exists alongside the latest edition of Title 24, the Building Energy Efficiency Standards, which took effect on January 1, 2017. CALGreen includes provisions to ensure the reduction of water use by 20%, improve indoor air quality, divert 50% of new construction waste from landfills, and inspect energy systems (i.e. heat furnace, air conditioner, mechanical equipment) for nonresidential buildings over 10,000 square feet to make sure that they're working according to design.

Title 24 applies to all buildings that are heated and/or mechanically cooled and are defined under the Uniform Building Code as A, B, E, H, N, R, or S occupancies, except registered historical buildings. Additions and renovations are also covered by the code. Institutional building's which include hospitals and prisons are not covered.

Local governmental agencies can modify the state energy code to be more stringent when documentation is provided to the California Energy Commission.

2019 Building Energy Efficiency Standards and Solar Requirement

The California Energy Commission adopted revisions to the Energy code in May 2018. The most noteworthy new provision is a requirement for all new low-rise homes to install photovoltaic (PV) equipment with an annual output greater than or equal to the homes annual electrical consumption. The code provides six exceptions to this rule, which are detailed in Subchapter 8 of the code. The proposed amended standards, which still need to be approved by the California Building Standards Commission would go into effect on January 1, 2020.

Program Overview

Implementing Sector: State
Category: Regulatory Policy
State: California
Incentive Type: Building Energy Code
Web Site:
Start Date:
Eligible Renewable/Other Technologies:
  • Solar - Passive
  • Solar Water Heat
  • Solar Photovoltaics
  • Comprehensive Measures/Whole Building
Residential Code: State developed code, Title 24, Part 6, exceeds 2015 IECC, and is mandatory statewide. Buildings must also meet certain requirements set by CALGreen, the statewide green building code.
Commercial Code: State developed code, Title 24, Part 6, meets or exceeds ASHRAE 90.1-2013, and is mandatory statewide. Buildings must also meet certain requirements set by CALGreen, the statewide green building code.
Code Change Cycle: Three-year code change cycle. The 2016 Standards took effect January 1, 2017.


Name: Maziar Shirakh
Organization: California Energy Commission
Address: 1516 Ninth St
Sacramento CA 95814-5512
Phone: (916) 654-3839

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.