ADU Regulations in Rancho Cucamonga, California (2026)

Regulations at a glance

Local rules & notes

Unpermitted ADU Amnesty: Local agencies are precluded from denying a permit for an unpermitted ADU constructed before January 1, 2020, unless it is a health and safety threat. Pre-approved Plan Fast-track: Agencies must approve or deny an application within 30 days if the applicant uses a pre-approved plan. Density Bonus Inclusion: ADUs can be counted as housing units to reach the five-unit minimum required to qualify for the State Density Bonus Law.

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

Frequently asked questions about ADU regulations in Rancho Cucamonga

• What is the maximum ADU size in Rancho Cucamonga, California?

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

• What are the setback requirements for ADUs in Rancho Cucamonga?

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

• What is the maximum height for an ADU in Rancho Cucamonga?

  In Rancho Cucamonga, 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 Rancho Cucamonga or county planning for your zone.

• Is ADU approval ministerial in Rancho Cucamonga?

  In Rancho Cucamonga, 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; Rancho Cucamonga planning can confirm the exact process.

• Are there parking requirements for ADUs in Rancho Cucamonga?

  In Rancho Cucamonga, 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 Rancho Cucamonga planning for your address.