Retaining Walls: Chino vs Ontario
How do retaining walls rules compare between Chino, CA and Ontario, CA?
Chino has fewer restrictions than Ontario.
Chino, CA
San Bernardino County
Per CBC § 105.2 (as adopted in CMC Title 15), retaining walls 4 ft or less in height (measured from bottom of footing to top of wall) and not supporting a surcharge are exempt from building permit. Taller walls or surcharge-loaded walls require permits, plans stamped by a licensed engineer, and inspections.
View full Chino rules →Ontario, CA
San Bernardino County
Ontario requires a permit for any retaining wall over 4 feet (footing to top) or carrying a surcharge such as a slope or driveway. Engineered plans by a licensed California civil or structural engineer are required.
View full Ontario rules →Key Facts Comparison
| Fact | Chino | Ontario |
|---|---|---|
| Permit-exempt height | ≤ 4 ft (no surcharge) | - |
| Permit-required threshold | Over 4 ft OR any surcharge | - |
| Code section | CBC § 105.2 (via CMC Title 15) | - |
| Engineered plans | Required for permitted walls | - |
| Combined fence-on-wall | Total height counted for zoning | - |
| Building Division | 909-334-3251 | - |
| No Permit | - | Up to 4 feet unsurcharged |
| Permit Required | - | Over 4 feet or surcharged |
| Plans | - | Licensed engineer required |
| Drainage | - | Cannot flow to neighbor |
| Measurement | - | Bottom of footing to top |
Highlighted rows indicate differences between cities.
Chino FAQ
Do I need a permit for a 3-foot landscape wall in Chino?
No, retaining walls 4 ft or less from footing bottom to top, with no surcharge load, are exempt under CBC § 105.2 as adopted in CMC Title 15.
When does my retaining wall require an engineer?
Any wall over 4 ft, or any wall supporting a surcharge (sloped fill, structure, driveway), needs engineered plans from a California-licensed civil or structural engineer.
Can I stack a 6-ft fence on a 4-ft retaining wall?
The wall may be permit-exempt, but the combined 10-ft height triggers fence permitting and zoning review. Contact Chino Building & Safety at 909-334-3251 first.
Ontario FAQ
Does a 3-foot retaining wall in Ontario need a permit?
Usually no if it is unsurcharged. If a slope, driveway, or pool loads the top of the wall, it is surcharged and does need a permit.
Who is liable if the wall fails?
The property owner. Using an engineer and permit creates a defensible record. Unpermitted walls expose you to liability for damage downhill and next door.
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