ADU Regulations in Williams, California (2026)

Regulations at a glance

Local rules & notes

Must Yield Provision: Front setbacks must yield to allow at least an 800 sq ft ADU if no other location on the lot is feasible. Fractional Unit Rounding: Specific rounding rules for multi-family ADU calculations where 0.5 or more rounds up to the next whole unit. Coastal Resource Protection: Additional restrictions apply in Environmentally Sensitive Habitat (ESH) areas, including arborist reports and view protection.

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

Frequently asked questions about ADU regulations in Williams

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

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

• What are the setback requirements for ADUs in Williams?

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

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

  In Williams, 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 Williams or county planning for your zone.

• Is ADU approval ministerial in Williams?

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

• Are there parking requirements for ADUs in Williams?

  In Williams, parking for ADUs is generally true. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Williams planning for your address.