Categorical Exemption

A class of projects that the California Secretary of Resources has determined does not have a significant effect on the environment and is therefore exempt from CEQA environmental review.

What is a Categorical Exemption?

A categorical exemption (Cat Ex) is a provision under CEQA that exempts certain classes of projects from environmental review because they have been determined, as a general matter, not to have significant environmental effects. There are 33 classes of categorical exemptions (Classes 1-33, codified in CEQA Guidelines Sections 15301-15333), covering a range of project types from minor alterations to in-fill development.

Common Categorical Exemptions

Frequently used exemptions include: Class 1 (existing facilities — minor alterations to existing structures), Class 3 (new construction of small structures), Class 4 (minor alterations to land), Class 11 (accessory structures), Class 15 (minor land divisions), and Class 32 (in-fill development projects meeting specific criteria including consistency with the general plan, within city limits, and on sites of no more than five acres). Class 32 is particularly important for urban development projects.

Exceptions to Categorical Exemptions

Categorical exemptions do not apply when there are unusual circumstances that create a reasonable possibility of significant effects, when the project affects environmental resources of hazardous or critical concern (scenic highways, wetlands, hazardous waste sites), or when the cumulative impact of successive projects of the same type in the same place is significant. These exceptions are frequent grounds for legal challenges.

Categorical Exemptions and Development

For developers, qualifying for a categorical exemption eliminates the time and cost of CEQA environmental review and significantly reduces litigation risk. Designing a project to fit within an applicable exemption category — particularly the Class 32 infill exemption — can save months of entitlement time. However, the exemption determination must be carefully documented, as opponents may challenge the applicability of the exemption.