ADU Regulations in Sunnyvale, California (2026)

Regulations at a glance

Local rules & notes

Front Setback Prohibition: The city attempted to prohibit ADUs in front yards, which HCD flagged as a violation of state law if it prevents an 800 sq ft unit. Nonconforming Zoning Conditions: The city cannot require applicants to fix existing non-compliant conditions on the property to get an ADU permit. Unit Count Restriction: The city tried to limit lots to only one ADU; HCD clarified that homeowners can combine a converted ADU, a detached ADU, and a JADU on a single-family lot. Entrance Location Restriction: The city restricted ADU entrances from being on the same wall plane as the primary dwelling, which HCD found to be an illegal constraint.

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

Frequently asked questions about ADU regulations in Sunnyvale

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

  In Sunnyvale, the maximum ADU size is typically 1000 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; Sunnyvale may follow state defaults or have local limits. Verify with Sunnyvale planning for your specific lot.

• What are the setback requirements for ADUs in Sunnyvale?

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

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

  In Sunnyvale, 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 Sunnyvale or county planning for your zone.

• Is ADU approval ministerial in Sunnyvale?

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

• Are there parking requirements for ADUs in Sunnyvale?

  In Sunnyvale, 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 Sunnyvale planning for your address.