ADU Regulations in Suisun City, California (2026)

Regulations at a glance

Local rules & notes

HOA Interference Prohibition: Homeowners' associations are prohibited from influencing the approval process or adding standards to ADU applications. Unpermitted ADU Amnesty: Local agencies cannot deny permits for unpermitted ADUs built before 2020 based on building code violations unless they are health/safety issues. Deed Restriction Ban: Local agencies are prohibited from imposing deed restrictions on ADUs as they are considered 'additional standards'.

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

Frequently asked questions about ADU regulations in Suisun City

• What is the maximum ADU size in Suisun City, California?

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

• What are the setback requirements for ADUs in Suisun City?

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

• What is the maximum height for an ADU in Suisun City?

  In Suisun City, 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 Suisun City or county planning for your zone.

• Is ADU approval ministerial in Suisun City?

  In Suisun City, 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; Suisun City planning can confirm the exact process.

• Are there parking requirements for ADUs in Suisun City?

  In Suisun City, 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 Suisun City planning for your address.