ADU Regulations in Irwindale, California (2026)

Regulations at a glance

Local rules & notes

Ordinance Null and Void: HCD warns that because the city's ordinance is from 2018, it fails to meet current state requirements and is considered 'null and void'. The city must apply state standards until a new ordinance is adopted. Unpermitted ADU Amnesty: Local agencies are prohibited from denying permits for unpermitted ADUs built before Jan 1, 2020, unless there is a health and safety violation. Deemed Approved Mechanism: Applications are deemed approved if the agency does not act within 60 days.

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

Frequently asked questions about ADU regulations in Irwindale

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

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

• What are the setback requirements for ADUs in Irwindale?

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

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

  In Irwindale, 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 Irwindale or county planning for your zone.

• Is ADU approval ministerial in Irwindale?

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

• Are there parking requirements for ADUs in Irwindale?

  In Irwindale, 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 Irwindale planning for your address.