ADU Regulations in Aliso Viejo, California (2026)

Regulations at a glance

Local rules & notes

Zero Impact Fees: The City's fee analysis indicates $0 for impact fees (Park, Open Space, Water/Sewer Connection, Storm Drain) for typical developments not subject to a development agreement. Designated Planner Assistance: The City identifies a designated planner to provide specific assistance to ADU applicants to encourage production. Zoning Table Anomaly: The permitted use table lists ADUs as 'Not Permitted' (NP) in High Density (RH) and Very High Density (RVH) zones, which contradicts state law requirements to allow ADUs in multifamily residential zones. The text, however, commits to state law consistency.

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

Frequently asked questions about ADU regulations in Aliso Viejo

• What is the maximum ADU size in Aliso Viejo, California?

  In Aliso Viejo, the maximum ADU size is typically 1200 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; Aliso Viejo may follow state defaults or have local limits. Verify with Aliso Viejo planning for your specific lot.

• What are the setback requirements for ADUs in Aliso Viejo?

  In Aliso Viejo, 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 Aliso Viejo planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in Aliso Viejo?

  In Aliso Viejo, 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 Aliso Viejo or county planning for your zone.

• Is ADU approval ministerial in Aliso Viejo?

  In Aliso Viejo, 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; Aliso Viejo planning can confirm the exact process.

• Are there parking requirements for ADUs in Aliso Viejo?

  In Aliso Viejo, 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 Aliso Viejo planning for your address.