ADU Regulations in Rialto, California (2026)

Regulations at a glance

Local rules & notes

Mandatory Demolition for Zoning Non-Compliance: Unlike many amnesty programs that offer zoning variances, Rialto requires that if a project does not meet Zoning codes, it cannot be legalized and must be demolished and restored to its original permitted condition. Enforcement Activity Freeze: The city freezes all code enforcement activities while a project is actively in the process of legalization, providing a safe harbor for owners to come forward. Post-Legalization Fee Waiver: Fees are not waived upfront; instead, they are waived only once the unit has been successfully legalized.

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

Frequently asked questions about ADU regulations in Rialto

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

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

• What are the setback requirements for ADUs in Rialto?

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

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

  In Rialto, 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 Rialto or county planning for your zone.

• Is ADU approval ministerial in Rialto?

  In Rialto, 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; Rialto planning can confirm the exact process.

• Are there parking requirements for ADUs in Rialto?

  In Rialto, 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 Rialto planning for your address.