ADU Regulations in Commerce, California (2026)

Regulations at a glance

Local rules & notes

Standard vs. Special ADU Categories: The city creates two distinct classes of ADUs. 'Standard' ADUs have larger size limits but are banned in Fire Hazard Zones. 'Special' ADUs are smaller (800 sq ft max) but allowed in Fire Hazard Zones and allow multi-unit configurations. Utility Undergrounding Requirement: Large ADU projects may trigger a requirement to underground utilities, with a waiver process available that incurs a 5% in-lieu fee. Front Yard ADU Allowance: ADUs are explicitly allowed in the front yard if they meet a 20-foot setback (or zone minimum), are under 17 feet tall, and are screened. Coastal Zone Restrictions: New detached ADUs in the Coastal Zone require a Coastal Development Permit and must comply with Coastal Land Use Plan policies.

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

Frequently asked questions about ADU regulations in Commerce

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

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

• What are the setback requirements for ADUs in Commerce?

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

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

  In Commerce, the maximum height for an ADU is generally 30 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 Commerce or county planning for your zone.

• Is ADU approval ministerial in Commerce?

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

• Are there parking requirements for ADUs in Commerce?

  In Commerce, 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 Commerce planning for your address.