ADU Regulations in Westminster, California (2026)

Regulations at a glance

Local rules & notes

ADU Type Combination Rule: HCD clarifies that the term 'any' in state law means 'all' listed types can be combined, allowing a converted ADU, a detached ADU, and a JADU on one lot. JADU Zoning Restriction: Unlike standard ADUs which are allowed in any residential or mixed-use zone, JADUs are strictly limited to single-family residential zones.

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

Frequently asked questions about ADU regulations in Westminster

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

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

• What are the setback requirements for ADUs in Westminster?

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

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

  In Westminster, 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 Westminster or county planning for your zone.

• Is ADU approval ministerial in Westminster?

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

• Are there parking requirements for ADUs in Westminster?

  In Westminster, 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 Westminster planning for your address.