ADU Regulations in Fairfield, California (2026)

Regulations at a glance

Local rules & notes

Deemed Approved Status: If the local agency has not approved or denied a completed application within 60 days, the application is deemed approved. HOA Restrictions Void: Homeowners' associations cannot influence the approval of an ADU application; third-party reviews by HOAs violate State ADU Law. Enforcement Delay (Amnesty): Agencies must delay enforcement for 5 years on unpermitted ADUs built before 2020 to allow for correction, provided there are no health/safety issues.

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

Frequently asked questions about ADU regulations in Fairfield

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

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

• What are the setback requirements for ADUs in Fairfield?

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

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

  In Fairfield, 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 Fairfield or county planning for your zone.

• Is ADU approval ministerial in Fairfield?

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

• Are there parking requirements for ADUs in Fairfield?

  In Fairfield, 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 Fairfield planning for your address.