ADU Regulations in Highland, California (2026)

Regulations at a glance

Local rules & notes

Utility Connection Fee Waiver: The city removed the requirement for separate utility stubs (sewer and water) for ADUs, which previously required expensive road cuts and separate meters. Mandatory ADU Signage: To assist emergency services, the city requires visible signage for the ADU from the front of the property. Camouflaged Entrance Requirement: Primary entrances for ADUs must be at the rear, or if on the side, must be hidden from street view by landscaping or fencing.

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

Frequently asked questions about ADU regulations in Highland

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

  In Highland, the maximum ADU size is typically 0 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; Highland may follow state defaults or have local limits. Verify with Highland planning for your specific lot.

• What are the setback requirements for ADUs in Highland?

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

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

  In Highland, 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 Highland or county planning for your zone.

• Is ADU approval ministerial in Highland?

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

• Are there parking requirements for ADUs in Highland?

  In Highland, 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 Highland planning for your address.