All energy calculations used for compliance with the Energy Standards must use the climate zone applicable to a building project is determined based on its physical location as it relates to the determinations of climate regions found in the California Energy Commission publication California Climate Zone Descriptions, which contains detailed survey definitions of the 16 climate zones.

The list of climate zone areas by ZIP code is located on the CEC website here:

https://www.energy.ca.gov/programs-and-topics/programs/building-energy-efficiency-standards/climate-zone-tool-maps-and

CEC has also developed an interactive climate zone lookup tool that allow user to locate climate zone by address or ZIP code. The lookup tool is located here:

http://caenergy.maps.arcgis.com/apps/webappviewer/index.html?id=4831772c00eb4f729924167244bbca22

Figure 100.1-A: California Climate Zones

Source: California Energy Commission