ADU Regulations in Santa Monica, California (2026)

Regulations at a glance

Local rules & notes

Non-Objective Rental Standards: The city attempted to require rental agreements to be in a 'form approved by the City Attorney,' which HCD ruled is not an objective standard. Illegal Placement Restrictions: The ordinance tried to restrict detached ADUs to the 'rear half of a parcel,' which HCD found inconsistent with state law protections for units under 800 sq ft. JADU Garage Conversion Rights: HCD clarified that JADUs must be allowed in attached garages as they are considered part of the primary residence.

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

Frequently asked questions about ADU regulations in Santa Monica

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

  In Santa Monica, 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; Santa Monica may follow state defaults or have local limits. Verify with Santa Monica planning for your specific lot.

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

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

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

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

• Is ADU approval ministerial in Santa Monica?

  In Santa Monica, 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 Monica planning can confirm the exact process.

• Are there parking requirements for ADUs in Santa Monica?

  In Santa Monica, parking for ADUs is generally Often waived per state law; check local ordinance. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Santa Monica planning for your address.