ADU Regulations in Etna, California (2026)

Regulations at a glance

Local rules & notes

Geographic Restriction: Unlike many modern ADU ordinances that apply citywide, this regulation restricts ADUs to specific mapped districts (Green Line, Mounds Park, Districts 1, 3, 7, 9). Minimum Lot Size Constraint: A strict minimum lot size of 5,000 sq. ft. is enforced, which the analysis maps show excludes a portion of properties in the allowed districts. Annual Owner-Occupancy Affidavit: Owners must file an annual affidavit verifying occupancy and pay an associated fee, a more active enforcement mechanism than simple deed restrictions found elsewhere.

For the official ordinance and latest updates, check your city or county planning department.

Frequently asked questions about ADU regulations in Etna

• What is the maximum ADU size in Etna, California?

  In Etna, the maximum ADU size is typically 800 square feet, depending on whether the unit is attached or detached. California state law allows up to 1,200 sq ft for detached ADUs and 800 sq ft for attached in many jurisdictions; Etna may follow state defaults or have local limits. Verify with Etna planning for your specific lot.

• What are the setback requirements for ADUs in Etna?

  In Etna, typical setback requirements are 4 feet from the side property line and 4 feet from the rear. These may be reduced to 4 feet under California Government Code § 65852.2 where applicable. Check with Etna planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in Etna?

  In Etna, the maximum height for an ADU is generally 16 feet. State law often allows up to 16 feet for detached ADUs and up to 25 feet when within 4 feet of the property line in some cases. Confirm with Etna or county planning for your zone.

• Is ADU approval ministerial in Etna?

  In Etna, ADU approval is typically Ministerial (by-right) per Gov Code §65852.2. Ministerial (by-right) review means the city must approve qualifying applications without discretionary review, per California Gov Code § 65852.2. Your project must still meet objective standards; Etna planning can confirm the exact process.

• Are there parking requirements for ADUs in Etna?

  In Etna, parking for ADUs is generally false. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Etna planning for your address.