Chino Hills, CA Accessory Structures: ADU Rules (2026)
ADU rules in Chino Hills, CA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Minimum size
- 220 sq ft (§16.10.140(I))
- Maximum size
- 850-1,000 sq ft interior livable space
- Side/rear setback
- 4 feet
- Height cap
- 1 story, 18 ft detached
- State law basis
- Implements Gov. Code § 65852.2
Summary
State law under Government Code § 65852.2 requires Chino Hills to allow accessory dwelling units, and the city's own standards in § 16.10.140 fill in the size, setback and height limits state law leaves to local control: a 220 square foot minimum, an 850 to 1,000 square foot maximum, four-foot side and rear setbacks, and an 18-foot height cap.
I.Minimum Size. Accessory dwelling units and junior accessory dwelling units shall have a minimum size of two hundred twenty (220) square feet.J.Maximum Size. The maximum size of an accessory dwelling unit shall not exceed eight hundred fifty (850) square feet of interior livable space for an accessory dwelling unit containing up to one bedroom, or one thousand (1,000) square feet of interior livable space for an accessory dwelling unit containing more than one bedroom...K.Setbacks. Accessory dwelling units and junior accessory dwelling units shall comply with the following setbacks:1.Front setback: Same as the primary dwelling.2.Side setbacks: Four feet to the property line.3.Rear setback: Four feet to the property line...M.Maximum Height. Accessory dwelling units shall not exceed one-story and eighteen (18) feet in height, except that an accessory dwelling unit attached to the primary dwelling shall not exceed the height of the existing primary dwelling or twenty-five (25) feet, whichever is greater.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 61).
Full Breakdown
140 of the Development Code, which fills in the standards state law leaves open to local jurisdictions. 140(I) and (J), an ADU or junior ADU must be at least 220 square feet, and a standalone ADU tops out at 850 square feet of interior livable space for a one-bedroom unit or 1,000 square feet for a unit with more than one bedroom; an attached ADU over 800 square feet also cannot exceed 50 percent of the primary dwelling's floor area. 140(K) are four feet from the side and rear property lines, with the front setback matching the primary dwelling, and no part of the structure may project into the four-foot side or rear buffer. 140(N)). 140(P)). 140(G)).
Violations & Fines
An ADU built without a permit, or that exceeds the size, height or setback standards of § 16.10.140, is a Development Code violation. Under § 1.36.010 and § 1.36.020, that is prosecutable as a misdemeanor with up to a $1,000 fine and six months in county jail, or the city may issue an administrative citation under Chapter 1.18 with fines set by council resolution and a right to administrative review and appeal to Superior Court under § 1.18.100.
Frequently Asked Questions
How big can an ADU be in Chino Hills?
What setbacks apply to a Chino Hills ADU?
Can Chino Hills ban ADUs from parts of the city?
Sources & Official References
Other rules in Chino Hills
How Chino Hills compares: Easiest Cities to Build an ADU·California rules heatmap·Compare Chino Hills to another location·View the California accessory structures overview
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ADU Rules in Nearby Cities
How other cities in San Bernardino County handle adu rules.