California Energy Code

The California Energy Code (also titled The Energy Efficiency Standards for Residential and Non-residential Buildings) is the sixth section of the California Building Standards Code. The code was created by the California Building Standards Commission in 1978 in response to a legislative mandate to reduce California's energy consumption. These standards are updated periodically by the California Energy Commission. The code includes energy conservation standards applicable to most buildings throughout California.
A 2020 study found that the 1978 energy code successfully reduced energy consumption, and that the implementation of the policy passed a cost-benefit test.
History.
California was the first state to implement minimum energy efficiency standards in 1974. It was the first to establish an energy regulation commission – the California Energy Commission. These regulations and codes have been in effect since 1974. California has the lowest per capita energy consumption in the US,
2008 Code.
Updated standards were adopted on April 23, 2008, and the Building Standards Commission approved them for publication on September 11, 2008. The 2008 Residential Compliance Manual was adopted by the Commission on December 17, 2008, and the 2008 non-residential Compliance Manual was adopted on January 14, 2009.
The 2008 changes to the Building Energy Efficiency Standards were intended to:
California governor Arnold Schwarzenegger challenged the CEC in 2008 to attain Zero Net Energy by 2020 for California Residential Building Code and issued a similar challenge for California's non-residential Building Code by 2030.
Purpose.
The code's purpose is to advance the state's energy policy, develop renewable energy sources and prepare for energy emergencies. The codes are divided into residential and non-residential sections. 
Structure.
The three general parts, which include all the responsibilities and criteria of the standards, are:
All buildings must follow the mandatory requirements. Performance standards vary by the building location and type.
These parts are designed to accomplish the following:
Climate Zones.
California has 16 different climate zones. Standards vary based on zone:
2019 Code.
The 2019 California Energy Code (Building Energy Efficiency Standards) become effective on January 1, 2020. It focuses on such areas such as residential photovoltaic systems, thermal envelope standards and non-residential lighting requirements.
Homes built under this code are about 53% more energy efficient than those built to comply with the 2016 Energy Code. Non-residential buildings were expected to use about 30% less electricity due to lighting upgrades. Residential home owners were expected to save $80 per month on heating, cooling and lighting, and improve indoor air quality. This code provides a market for "smart" technologies.
The 2019 Code added photovoltaic system requirements for low-rise residential buildings. Exceptions grant a reduction in size for photo-voltaic systems.
The 2019 Code has simpler non-residential forms and reduces their number from 47 forms to 10. Each building component has one form per category: