ADU Regulations in Fremont, California (2026)

Regulations at a glance

Local rules & notes

Tiered Detached Size Limits: Fremont imposes a stricter 1,000 sq ft limit on detached ADUs for lots under 10,000 sq ft, while allowing the full state max of 1,200 sq ft only on larger lots. Historic Preservation Constraints: ADUs on historic properties or involving exterior modifications to historic structures must conform to Secretary of the Interior's Standards. Hillside and Open Space Districts: Specific zoning overlays apply for Hillside (H-I) and Open Space (OS) districts which may supersede standard ADU placement rules.

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

Frequently asked questions about ADU regulations in Fremont

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

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

• What are the setback requirements for ADUs in Fremont?

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

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

  In Fremont, 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 Fremont or county planning for your zone.

• Is ADU approval ministerial in Fremont?

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

• Are there parking requirements for ADUs in Fremont?

  In Fremont, parking for ADUs is generally 1 space per unit. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Fremont planning for your address.