ADU Regulations in Hidden Hills, California (2026)

Regulations at a glance

Local rules & notes

No Traffic Impact Fee: Unlike many surrounding jurisdictions, Hidden Hills does not charge a traffic impact fee for development. Gated Community Context: Nearly the entire city is a private guard-gated community, which creates unique constraints and reliance on ADUs for affordable housing inventory. Deed-Restricted ADU Incentives: The City offers modified development standards specifically for second units that are deed-restricted for lower-income households.

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

Frequently asked questions about ADU regulations in Hidden Hills

• What is the maximum ADU size in Hidden Hills, California?

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

• What are the setback requirements for ADUs in Hidden Hills?

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

• What is the maximum height for an ADU in Hidden Hills?

  In Hidden Hills, 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 Hidden Hills or county planning for your zone.

• Is ADU approval ministerial in Hidden Hills?

  In Hidden Hills, 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; Hidden Hills planning can confirm the exact process.

• Are there parking requirements for ADUs in Hidden Hills?

  In Hidden Hills, 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 Hidden Hills planning for your address.