ADU Regulations in Vallejo, California (2026)

Regulations at a glance

Local rules & notes

Unpermitted ADU Amnesty: Local agencies must delay enforcement on building code violations for unpermitted ADUs built before 2020 for five years, provided they are not health/safety issues. HOA Interference Prohibited: Homeowners’ associations are legally barred from influencing or reviewing ADU applications as a third party. 60-Day Deemed Approval: Applications are automatically deemed approved if the city fails to act within 60 days of a completed submission.

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

Frequently asked questions about ADU regulations in Vallejo

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

  In Vallejo, the maximum ADU size is typically 850 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; Vallejo may follow state defaults or have local limits. Verify with Vallejo planning for your specific lot.

• What are the setback requirements for ADUs in Vallejo?

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

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

  In Vallejo, 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 Vallejo or county planning for your zone.

• Is ADU approval ministerial in Vallejo?

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

• Are there parking requirements for ADUs in Vallejo?

  In Vallejo, 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 Vallejo planning for your address.