ADU Regulations in Santa Ana, California (2026)

Regulations at a glance

Local rules & notes

Pre-approved ADU Prototype Plans: The city has committed to publishing pre-approved ADU prototype plans to provide greater certainty and quality while reducing development costs for residents. ADU Amnesty Program: The city is creating a housing amnesty program to facilitate the legalization of unpermitted housing units, including ADUs, to address life safety issues. ADU Fee Reduction Study: The city is actively studying ADU plan review fees to seek opportunities to reduce the overall cost of developing ADUs.

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

Frequently asked questions about ADU regulations in Santa Ana

• What is the maximum ADU size in Santa Ana, California?

  In Santa Ana, the maximum ADU size is typically 1000 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; Santa Ana may follow state defaults or have local limits. Verify with Santa Ana planning for your specific lot.

• What are the setback requirements for ADUs in Santa Ana?

  In Santa Ana, 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 Santa Ana planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in Santa Ana?

  In Santa Ana, 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 Santa Ana or county planning for your zone.

• Is ADU approval ministerial in Santa Ana?

  In Santa Ana, 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; Santa Ana planning can confirm the exact process.

• Are there parking requirements for ADUs in Santa Ana?

  In Santa Ana, 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 Santa Ana planning for your address.