ADU Regulations in San Ramon, California (2026)

Regulations at a glance

Local rules & notes

Generous Attached ADU Height: The city allows attached ADUs to reach 25 feet in height, which is much higher than the 16-foot state minimum, facilitating two-story attached additions. Conflicting Size Standards: The development standards for detached units provide two different maximums for one-bedroom units (850 sqft and 1,200 sqft) within the same paragraph. Significant Front Setback: The city requires a 20-foot front setback for detached ADUs, which is more restrictive than the 4-foot side/rear setbacks, though state law may allow encroachment for units under 800 sqft.

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

Frequently asked questions about ADU regulations in San Ramon

• What is the maximum ADU size in San Ramon, California?

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

• What are the setback requirements for ADUs in San Ramon?

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

• What is the maximum height for an ADU in San Ramon?

  In San Ramon, 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 San Ramon or county planning for your zone.

• Is ADU approval ministerial in San Ramon?

  In San Ramon, 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; San Ramon planning can confirm the exact process.

• Are there parking requirements for ADUs in San Ramon?

  In San Ramon, 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 San Ramon planning for your address.